1
|
Kussauer S, Dilk P, Elleisy M, Michaelis C, Lichtwark S, Rimmbach C, David R, Jung J. Heart rhythm in vitro: measuring stem cell-derived pacemaker cells on microelectrode arrays. Front Cardiovasc Med 2024; 11:1200786. [PMID: 38450366 PMCID: PMC10915086 DOI: 10.3389/fcvm.2024.1200786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 02/05/2024] [Indexed: 03/08/2024] Open
Abstract
Background Cardiac arrhythmias have markedly increased in recent decades, highlighting the urgent need for appropriate test systems to evaluate the efficacy and safety of new pharmaceuticals and the potential side effects of established drugs. Methods The Microelectrode Array (MEA) system may be a suitable option, as it provides both real-time and non-invasive monitoring of cellular networks of spontaneously active cells. However, there is currently no commercially available cell source to apply this technology in the context of the cardiac conduction system (CCS). In response to this problem, our group has previously developed a protocol for the generation of pure functional cardiac pacemaker cells from mouse embryonic stem cells (ESCs). In addition, we compared the hanging drop method, which was previously utilized, with spherical plate-derived embryoid bodies (EBs) and the pacemaker cells that are differentiated from these. Results We described the application of these pacemaker cells on the MEA platform, which required a number of crucial optimization steps in terms of coating, dissociation, and cell density. As a result, we were able to generate a monolayer of pure pacemaker cells on an MEA surface that is viable and electromechanically active for weeks. Furthermore, we introduced spherical plates as a convenient and scalable method to be applied for the production of induced sinoatrial bodies. Conclusion We provide a tool to transfer modeling and analysis of cardiac rhythm diseases to the cell culture dish. Our system allows answering CCS-related queries within a cellular network, both under baseline conditions and post-drug exposure in a reliable and affordable manner. Ultimately, our approach may provide valuable guidance not only for cardiac pacemaker cells but also for the generation of an MEA test platform using other sensitive non-proliferating cell types.
Collapse
Affiliation(s)
- Sophie Kussauer
- Department of Cardiac Surgery, Rostock University Medical Centre, Rostock, Germany
- Department of Life, Light, & Matter, University of Rostock, Rostock, Germany
| | - Patrick Dilk
- Department of Cardiac Surgery, Rostock University Medical Centre, Rostock, Germany
- Department of Life, Light, & Matter, University of Rostock, Rostock, Germany
| | - Moustafa Elleisy
- Department of Cardiac Surgery, Rostock University Medical Centre, Rostock, Germany
- Department of Life, Light, & Matter, University of Rostock, Rostock, Germany
| | - Claudia Michaelis
- Department of Cardiac Surgery, Rostock University Medical Centre, Rostock, Germany
- Department of Life, Light, & Matter, University of Rostock, Rostock, Germany
| | - Sarina Lichtwark
- Department of Cardiac Surgery, Rostock University Medical Centre, Rostock, Germany
- Department of Life, Light, & Matter, University of Rostock, Rostock, Germany
| | - Christian Rimmbach
- Department of Cardiac Surgery, Rostock University Medical Centre, Rostock, Germany
- Department of Life, Light, & Matter, University of Rostock, Rostock, Germany
| | - Robert David
- Department of Cardiac Surgery, Rostock University Medical Centre, Rostock, Germany
- Department of Life, Light, & Matter, University of Rostock, Rostock, Germany
| | - Julia Jung
- Department of Cardiac Surgery, Rostock University Medical Centre, Rostock, Germany
- Department of Life, Light, & Matter, University of Rostock, Rostock, Germany
| |
Collapse
|
2
|
Sommerfeld LC, Holmes AP, Yu TY, O'Shea C, Kavanagh DM, Pike JM, Wright T, Syeda F, Aljehani A, Kew T, Cardoso VR, Kabir SN, Hepburn C, Menon PR, Broadway-Stringer S, O'Reilly M, Witten A, Fortmueller L, Lutz S, Kulle A, Gkoutos GV, Pavlovic D, Arlt W, Lavery GG, Steeds R, Gehmlich K, Stoll M, Kirchhof P, Fabritz L. Reduced plakoglobin increases the risk of sodium current defects and atrial conduction abnormalities in response to androgenic anabolic steroid abuse. J Physiol 2024. [PMID: 38345865 DOI: 10.1113/jp284597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 01/16/2024] [Indexed: 03/07/2024] Open
Abstract
Androgenic anabolic steroids (AAS) are commonly abused by young men. Male sex and increased AAS levels are associated with earlier and more severe manifestation of common cardiac conditions, such as atrial fibrillation, and rare ones, such as arrhythmogenic right ventricular cardiomyopathy (ARVC). Clinical observations suggest a potential atrial involvement in ARVC. Arrhythmogenic right ventricular cardiomyopathy is caused by desmosomal gene defects, including reduced plakoglobin expression. Here, we analysed clinical records from 146 ARVC patients to identify that ARVC is more common in males than females. Patients with ARVC also had an increased incidence of atrial arrhythmias and P wave changes. To study desmosomal vulnerability and the effects of AAS on the atria, young adult male mice, heterozygously deficient for plakoglobin (Plako+/- ), and wild type (WT) littermates were chronically exposed to 5α-dihydrotestosterone (DHT) or placebo. The DHT increased atrial expression of pro-hypertrophic, fibrotic and inflammatory transcripts. In mice with reduced plakoglobin, DHT exaggerated P wave abnormalities, atrial conduction slowing, sodium current depletion, action potential amplitude reduction and the fall in action potential depolarization rate. Super-resolution microscopy revealed a decrease in NaV 1.5 membrane clustering in Plako+/- atrial cardiomyocytes after DHT exposure. In summary, AAS combined with plakoglobin deficiency cause pathological atrial electrical remodelling in young male hearts. Male sex is likely to increase the risk of atrial arrhythmia, particularly in those with desmosomal gene variants. This risk is likely to be exaggerated further by AAS use. KEY POINTS: Androgenic male sex hormones, such as testosterone, might increase the risk of atrial fibrillation in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC), which is often caused by desmosomal gene defects (e.g. reduced plakoglobin expression). In this study, we observed a significantly higher proportion of males who had ARVC compared with females, and atrial arrhythmias and P wave changes represented a common observation in advanced ARVC stages. In mice with reduced plakoglobin expression, chronic administration of 5α-dihydrotestosterone led to P wave abnormalities, atrial conduction slowing, sodium current depletion and a decrease in membrane-localized NaV 1.5 clusters. 5α-Dihydrotestosterone, therefore, represents a stimulus aggravating the pro-arrhythmic phenotype in carriers of desmosomal mutations and can affect atrial electrical function.
Collapse
Affiliation(s)
- Laura C Sommerfeld
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
- University Center of Cardiovascular Science, University Heart and Vascular Center, UKE Hamburg, Hamburg, Germany
- German Center for Cardiovascular Research (DZHK), Standort Hamburg/Kiel/Lübeck, Germany
| | - Andrew P Holmes
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
- School of Biomedical Sciences, Institute of Clinical Sciences, University of Birmingham, Birmingham, UK
| | - Ting Y Yu
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
- Research and Training Centre in Physical Sciences for Health, Birmingham, UK
| | - Christopher O'Shea
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
- Research and Training Centre in Physical Sciences for Health, Birmingham, UK
| | - Deirdre M Kavanagh
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
- Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, UK
| | - Jeremy M Pike
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
- Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, UK
| | - Thomas Wright
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
| | - Fahima Syeda
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
| | - Areej Aljehani
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
| | - Tania Kew
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
| | - Victor R Cardoso
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, UK
| | - S Nashitha Kabir
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
| | - Claire Hepburn
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
| | - Priyanka R Menon
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
| | | | - Molly O'Reilly
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
| | - Anika Witten
- Genetic Epidemiology, Institute for Human Genetics, University of Münster, Münster, Germany
- Core Facility Genomics of the Medical Faculty, University of Münster, Münster, Germany
| | - Lisa Fortmueller
- University Center of Cardiovascular Science, University Heart and Vascular Center, UKE Hamburg, Hamburg, Germany
- German Center for Cardiovascular Research (DZHK), Standort Hamburg/Kiel/Lübeck, Germany
- Genetic Epidemiology, Institute for Human Genetics, University of Münster, Münster, Germany
| | - Susanne Lutz
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, Göttingen, Germany
| | - Alexandra Kulle
- Division of Paediatric Endocrinology and Diabetes, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Georgios V Gkoutos
- University Center of Cardiovascular Science, University Heart and Vascular Center, UKE Hamburg, Hamburg, Germany
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, UK
- Institute of Translational Medicine, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
- MRC Health Data Research UK (HDR), Midlands Site, UK
| | - Davor Pavlovic
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
| | - Wiebke Arlt
- Institute of Metabolism and Systems Research (IMSR), University of Birmingham, Birmingham, UK
- Centre for Endocrinology, Diabetes and Metabolism (CEDAM), Birmingham Health Partners, Birmingham, UK
- Medical Research Council London Institute of Medical Sciences, London UK & Institute of Clinical Sciences, Faculty of Medicine, Imperial College, London, UK
| | - Gareth G Lavery
- Institute of Metabolism and Systems Research (IMSR), University of Birmingham, Birmingham, UK
- Centre for Endocrinology, Diabetes and Metabolism (CEDAM), Birmingham Health Partners, Birmingham, UK
| | - Richard Steeds
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
- Department of Cardiology, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Katja Gehmlich
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
| | - Monika Stoll
- Genetic Epidemiology, Institute for Human Genetics, University of Münster, Münster, Germany
- Core Facility Genomics of the Medical Faculty, University of Münster, Münster, Germany
- Cardiovascular Research Institute Maastricht, Department of Biochemistry, Maastricht University, Maastricht, The Netherlands
| | - Paulus Kirchhof
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
- German Center for Cardiovascular Research (DZHK), Standort Hamburg/Kiel/Lübeck, Germany
- Department of Cardiology, University Heart & Vascular Center Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Larissa Fabritz
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
- University Center of Cardiovascular Science, University Heart and Vascular Center, UKE Hamburg, Hamburg, Germany
- German Center for Cardiovascular Research (DZHK), Standort Hamburg/Kiel/Lübeck, Germany
- Department of Cardiology, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
- Department of Cardiology, University Heart & Vascular Center Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| |
Collapse
|
3
|
Sekihara T, Oka T, Ozu K, Sakata Y. Quantitative analysis of fractionated electrogram area of left atrium during right atrial pacing as an indicator of left atrial electrical remodeling in patients with atrial fibrillation. J Arrhythm 2024; 40:90-99. [PMID: 38333386 PMCID: PMC10848603 DOI: 10.1002/joa3.12971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 10/19/2023] [Accepted: 11/20/2023] [Indexed: 02/10/2024] Open
Abstract
Background The clinical significance of left atrial local electrogram fractionation after restoration of sinus rhythm in patients with atrial fibrillation (AF) has not been elucidated. Methods We evaluated ultrahigh-resolution maps of the left atrium (LA) during RA pacing acquired after pulmonary vein isolation in 40 patients with AF. The association between low-voltage area (LVA, <0.5 mV), fractionated electrogram area (FEA, the highlighted area with LUMIPOINT™ Complex Activation), the interval from onset of LA activation to wavefront collision at the mitral isthmus (LA activation time), and wave propagation velocity (WPV) was evaluated quantitatively. Results The total LVA, total FEA with ≥5.0 peaks or ≥7.0 peaks were 7.0 ± 7.9 cm2, 15.9 ± 12.9 cm2, and 5.2 ± 7.5 cm2, respectively. These areas were predominantly observed in the anteroseptal region. Total LVA, total FEA with ≥5.0 peaks, and total FEA with ≥5.0 peaks in the normal voltage area (NVA: ≥0.5 mV) correlated with LA activation time (R = 0.69, 0.75, and 0.71; each p < .0001). In the anterior wall, these areas correlated with regional mean WPV (R = -0.75, -0.83, and - 0.55; each p < .0001) and the extent of slow conduction area (SCA) with WPV <0.3 m/s (R = 0.89, 0.84, 0.33; p < .0001 for LVA and FEA, p < .05 for FEA located in NVA). The anterior wall FEA with ≥7.0 peaks and that in the NVA showed a better correlation in predicting anterior wall SCA (R = 0.92 and 0.86, each p < .0001). Conclusion Quantitative analysis of FEA together with LVA may facilitate the assessment of LA electrical remodeling.
Collapse
Affiliation(s)
- Takayuki Sekihara
- Department of Cardiovascular MedicineOsaka University Graduate School of MedicineOsakaJapan
| | - Takafumi Oka
- Department of Cardiovascular MedicineOsaka University Graduate School of MedicineOsakaJapan
| | - Kentaro Ozu
- Department of Cardiovascular MedicineOsaka University Graduate School of MedicineOsakaJapan
| | - Yasushi Sakata
- Department of Cardiovascular MedicineOsaka University Graduate School of MedicineOsakaJapan
| |
Collapse
|
4
|
Okubo Y, Oguri N, Sakai T, Uotani Y, Furutani M, Miyamoto S, Miyauchi S, Okamura S, Tokuyama T, Nakano Y. Conduction velocity mapping in atrial fibrillation using omnipolar technology. Pacing Clin Electrophysiol 2024; 47:19-27. [PMID: 38041418 DOI: 10.1111/pace.14899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 11/16/2023] [Accepted: 11/24/2023] [Indexed: 12/03/2023]
Abstract
BACKGROUND Recent studies have shown that atrial slow conduction velocity (CV) is associated with the perpetuation of atrial fibrillation (AF). However, the criteria of CV measurement have not been standardized. The aim of this study was to evaluate the relationship between the slow CV area (SCVA) measured by novel omnipolar technology (OT) and AF recurrence. METHODS This study included 90 patients with AF who underwent initial pulmonary vein isolation (PVI). The segmented surface area of the SCVA was measured by left atrial (LA) electrophysiological mapping using OT before the PVI. The proportion of the SCVA at each cutoff value of CV (from < 0.6 to < 0.9 m/s) was compared between the patients with and without AF recurrence. RESULTS During a mean follow-up period of 516 ± 197 days, the recurrence of AF after the initial PVI was observed in 23 (25.5%) patients. In patients with AF recurrence, the proportion of the SCVA in the LA posterior, LA appendage (LAA), and LA anterior were significantly higher than those without AF recurrence. The multivariate analysis indicated that the proportion of the low voltage area and the SCVA in the LA anterior (local CV < 0.7 m/s) were independent predictors of AF recurrence (hazard ratio [HR], 1.07; 95% confidence interval [CI], 1.01-1.14; p = 0.03; HR, 1.40; 95% CI, 1.07-1.83; p = 0.01, respectively). CONCLUSION By evaluating the local CV using OT, it was indicated that SCVA with CV < 0.7 m/s in the LA anterior is strongly associated with AF recurrence after PVI.
Collapse
Affiliation(s)
- Yousaku Okubo
- Department of Cardiovascular Medicine, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
| | - Naoto Oguri
- Department of Cardiovascular Medicine, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
| | - Takumi Sakai
- Department of Cardiovascular Medicine, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
| | - Yukimi Uotani
- Department of Cardiovascular Medicine, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
| | - Motoki Furutani
- Department of Cardiovascular Medicine, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
| | - Shogo Miyamoto
- Department of Cardiovascular Medicine, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
| | - Shunsuke Miyauchi
- Department of Cardiovascular Medicine, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
| | - Sho Okamura
- Department of Cardiovascular Medicine, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
| | - Takehito Tokuyama
- Department of Cardiovascular Medicine, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
| | - Yukiko Nakano
- Department of Cardiovascular Medicine, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
| |
Collapse
|
5
|
Macheret F, Bifulco SF, Scott GD, Kwan KT, Chahine Y, Afroze T, McDonagh R, Akoum N, Boyle PM. Comparing Inducibility of Re-Entrant Arrhythmia in Patient-Specific Computational Models to Clinical Atrial Fibrillation Phenotypes. JACC Clin Electrophysiol 2023; 9:2149-2162. [PMID: 37656099 PMCID: PMC10909381 DOI: 10.1016/j.jacep.2023.06.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 06/21/2023] [Accepted: 06/30/2023] [Indexed: 09/02/2023]
Abstract
BACKGROUND Computational models of fibrosis-mediated, re-entrant left atrial (LA) arrhythmia can identify possible substrate for persistent atrial fibrillation (AF) ablation. Contemporary models use a 1-size-fits-all approach to represent electrophysiological properties, limiting agreement between simulations and patient outcomes. OBJECTIVES The goal of this study was to test the hypothesis that conduction velocity (ϴ) modulation in persistent AF models can improve simulation agreement with clinical arrhythmias. METHODS Patients with persistent AF (n = 37) underwent ablation and were followed up for ≥2 years to determine post-ablation outcomes: AF, atrial flutter (AFL), or no recurrence. Patient-specific LA models (n = 74) were constructed using pre-ablation and ≥90 days' post-ablation magnetic resonance imaging data. Simulated pacing gauged in silico arrhythmia inducibility due to AF-like rotors or AFL-like macro re-entrant tachycardias. A physiologically plausible range of ϴ values (±10 or 20% vs. baseline) was tested, and model/clinical agreement was assessed. RESULTS Fifteen (41%) patients had a recurrence with AF and 6 (16%) with AFL. Arrhythmia was induced in 1,078 of 5,550 simulations. Using baseline ϴ, model/clinical agreement was 46% (34 of 74 models), improving to 65% (48 of 74) when any possible ϴ value was used (McNemar's test, P = 0.014). ϴ modulation improved model/clinical agreement in both pre-ablation and post-ablation models. Pre-ablation model/clinical agreement was significantly greater for patients with extensive LA fibrosis (>17.2%) and an elevated body mass index (>32.0 kg/m2). CONCLUSIONS Simulations in persistent AF models show a 41% relative improvement in model/clinical agreement when ϴ is modulated. Patient-specific calibration of ϴ values could improve model/clinical agreement and model usefulness, especially in patients with higher body mass index or LA fibrosis burden. This could ultimately facilitate better personalized modeling, with immediate clinical implications.
Collapse
Affiliation(s)
- Fima Macheret
- Division of Cardiology, University of Washington, Seattle, Washington, USA
| | - Savannah F Bifulco
- Department of Bioengineering, University of Washington, Seattle, Washington, USA
| | - Griffin D Scott
- Department of Bioengineering, University of Washington, Seattle, Washington, USA
| | - Kirsten T Kwan
- Department of Bioengineering, University of Washington, Seattle, Washington, USA
| | - Yaacoub Chahine
- Division of Cardiology, University of Washington, Seattle, Washington, USA
| | - Tanzina Afroze
- Division of Cardiology, University of Washington, Seattle, Washington, USA
| | | | - Nazem Akoum
- Division of Cardiology, University of Washington, Seattle, Washington, USA; Department of Bioengineering, University of Washington, Seattle, Washington, USA.
| | - Patrick M Boyle
- Department of Bioengineering, University of Washington, Seattle, Washington, USA; Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, Washington, USA; Center for Cardiovascular Biology, University of Washington, Seattle, Washington, USA.
| |
Collapse
|
6
|
Oliveira R, De Lucia M, Lutti A. Single-subject electroencephalography measurement of interhemispheric transfer time for the in-vivo estimation of axonal morphology. Hum Brain Mapp 2023; 44:4859-4874. [PMID: 37470446 PMCID: PMC10472916 DOI: 10.1002/hbm.26420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 06/12/2023] [Accepted: 06/26/2023] [Indexed: 07/21/2023] Open
Abstract
Assessing axonal morphology in vivo opens new avenues for the combined study of brain structure and function. A novel approach has recently been introduced to estimate the morphology of axonal fibers from the combination of magnetic resonance imaging (MRI) data and electroencephalography (EEG) measures of the interhemispheric transfer time (IHTT). In the original study, the IHTT measures were computed from EEG data averaged across a group, leading to bias of the axonal morphology estimates. Here, we seek to estimate axonal morphology from individual measures of IHTT, obtained from EEG data acquired in a visual evoked potential experiment. Subject-specific IHTTs are computed in a data-driven framework with minimal a priori constraints, based on the maximal peak of neural responses to visual stimuli within periods of statistically significant evoked activity in the inverse solution space. The subject-specific IHTT estimates ranged from 8 to 29 ms except for one participant and the between-session variability was comparable to between-subject variability. The mean radius of the axonal radius distribution, computed from the IHTT estimates and the MRI data, ranged from 0 to 1.09 μm across subjects. The change in axonal g-ratio with axonal radius ranged from 0.62 to 0.81 μm-α . The single-subject measurement of the IHTT yields estimates of axonal morphology that are consistent with histological values. However, improvement of the repeatability of the IHTT estimates is required to improve the specificity of the single-subject axonal morphology estimates.
Collapse
Affiliation(s)
- Rita Oliveira
- Laboratory for Research in Neuroimaging, Department of Clinical NeuroscienceLausanne University Hospital and University of LausanneLausanneSwitzerland
| | - Marzia De Lucia
- Laboratory for Research in Neuroimaging, Department of Clinical NeuroscienceLausanne University Hospital and University of LausanneLausanneSwitzerland
| | - Antoine Lutti
- Laboratory for Research in Neuroimaging, Department of Clinical NeuroscienceLausanne University Hospital and University of LausanneLausanneSwitzerland
| |
Collapse
|
7
|
Djemai M, Cupelli M, Boutjdir M, Chahine M. Optical Mapping of Cardiomyocytes in Monolayer Derived from Induced Pluripotent Stem Cells. Cells 2023; 12:2168. [PMID: 37681899 PMCID: PMC10487143 DOI: 10.3390/cells12172168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 08/21/2023] [Accepted: 08/25/2023] [Indexed: 09/09/2023] Open
Abstract
Optical mapping is a powerful imaging technique widely adopted to measure membrane potential changes and intracellular Ca2+ variations in excitable tissues using voltage-sensitive dyes and Ca2+ indicators, respectively. This powerful tool has rapidly become indispensable in the field of cardiac electrophysiology for studying depolarization wave propagation, estimating the conduction velocity of electrical impulses, and measuring Ca2+ dynamics in cardiac cells and tissues. In addition, mapping these electrophysiological parameters is important for understanding cardiac arrhythmia mechanisms. In this review, we delve into the fundamentals of cardiac optical mapping technology and its applications when applied to hiPSC-derived cardiomyocytes and discuss related advantages and challenges. We also provide a detailed description of the processing and analysis of optical mapping data, which is a crucial step in the study of cardiac diseases and arrhythmia mechanisms for extracting and comparing relevant electrophysiological parameters.
Collapse
Affiliation(s)
- Mohammed Djemai
- CERVO Brain Research Center, Institut Universitaire en Santé Mentale de Québec, Quebec City, QC G1J 2G3, Canada
| | - Michael Cupelli
- Cardiovascular Research Program, VA New York Harbor Healthcare System, New York, NY 11209, USA
- Department of Medicine, Cell Biology and Pharmacology, State University of New York Downstate Health Sciences University, New York, NY 11203, USA
| | - Mohamed Boutjdir
- Cardiovascular Research Program, VA New York Harbor Healthcare System, New York, NY 11209, USA
- Department of Medicine, Cell Biology and Pharmacology, State University of New York Downstate Health Sciences University, New York, NY 11203, USA
- Department of Medicine, NYU School of Medicine, New York, NY 10016, USA
| | - Mohamed Chahine
- CERVO Brain Research Center, Institut Universitaire en Santé Mentale de Québec, Quebec City, QC G1J 2G3, Canada
- Department of Medicine, Faculty of Medicine, Université Laval, Quebec City, QC G1V 0A6, Canada
| |
Collapse
|
8
|
Wilhelm TI, Lewalter T, Fischer J, Reiser J, Werner J, Baumgartner C, Gleirscher L, Hoppmann P, Kupatt C, Tiemann K, Jilek C. Electroanatomical Conduction Characteristics of Pig Myocardial Tissue Derived from High-Density Mapping. J Clin Med 2023; 12:5598. [PMID: 37685665 PMCID: PMC10488835 DOI: 10.3390/jcm12175598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 08/19/2023] [Accepted: 08/22/2023] [Indexed: 09/10/2023] Open
Abstract
BACKGROUND Ultra-high-density mapping systems allow more precise measurement of the heart chambers at corresponding conduction velocities (CVs) and voltage amplitudes (VAs). Our aim for this study was to define and compare a basic value set for unipolar CV and VA in all four heart chambers and their separate walls in healthy, juvenile porcine hearts using ultra-high-density mapping. METHODS We used the Rhythmia Mapping System to create electroanatomical maps of four pig hearts in sinus rhythm. CVs and VAs were calculated for chambers and wall segments with overlapping circular areas (radius of 5 mm). RESULTS We analysed 21 maps with a resolution of 1.4 points/mm2. CVs were highest in the left atrium (LA), followed by the left ventricle (LV), right ventricle (RV), and right atrium (RA). As for VA, LV was highest, followed by RV, LA, and RA. The left chambers had a higher overall CV and VA than the right. Within the chambers, CV varied more in the right than in the left chambers, and VA varied in the ventricles but not in the atria. There was a slightly positive correlation between CVs and VAs at velocity values of <1.5 m/s. CONCLUSIONS In healthy porcine hearts, the left chambers showed higher VAs and CVs than the right. CV differs mainly within the right chambers and VA differs only within the ventricles. A slightly positive linear correlation was found between slow CVs and low VAs.
Collapse
Affiliation(s)
- Theresa Isabelle Wilhelm
- Peter-Osypka Heart Centre Munich, Internistisches Klinikum München Süd, 81379 Munich, Germany (T.L.)
- Medical Graduate Center, School of Medicine, Technical University of Munich, 81675 Munich, Germany
| | - Thorsten Lewalter
- Peter-Osypka Heart Centre Munich, Internistisches Klinikum München Süd, 81379 Munich, Germany (T.L.)
| | - Johannes Fischer
- Center for Preclinical Research, University Hospital Rechts der Isar, Technical University of Munich, 81675 Munich, Germany
| | - Judith Reiser
- Center for Preclinical Research, University Hospital Rechts der Isar, Technical University of Munich, 81675 Munich, Germany
| | - Julia Werner
- Center for Preclinical Research, University Hospital Rechts der Isar, Technical University of Munich, 81675 Munich, Germany
| | - Christine Baumgartner
- Center for Preclinical Research, University Hospital Rechts der Isar, Technical University of Munich, 81675 Munich, Germany
| | - Lukas Gleirscher
- Peter-Osypka Heart Centre Munich, Internistisches Klinikum München Süd, 81379 Munich, Germany (T.L.)
| | - Petra Hoppmann
- Department of Internal Medicine I, University Hospital Rechts der Isar, Technical University of Munich, 81675 Munich, Germany
| | - Christian Kupatt
- Department of Internal Medicine I, University Hospital Rechts der Isar, Technical University of Munich, 81675 Munich, Germany
| | - Klaus Tiemann
- Peter-Osypka Heart Centre Munich, Internistisches Klinikum München Süd, 81379 Munich, Germany (T.L.)
- Department of Internal Medicine I, University Hospital Rechts der Isar, Technical University of Munich, 81675 Munich, Germany
| | - Clemens Jilek
- Peter-Osypka Heart Centre Munich, Internistisches Klinikum München Süd, 81379 Munich, Germany (T.L.)
- Department of Internal Medicine I, University Hospital Rechts der Isar, Technical University of Munich, 81675 Munich, Germany
| |
Collapse
|
9
|
Tung R, Tamarappoo B, Morris MF. Scar, Fat, and Fibrosis: Rethinking Re-Entry. JACC Clin Electrophysiol 2023; 9:1246-1247. [PMID: 37558286 DOI: 10.1016/j.jacep.2023.06.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Revised: 06/29/2023] [Accepted: 06/29/2023] [Indexed: 08/11/2023]
Affiliation(s)
- Roderick Tung
- Division of Cardiology, Banner University Medical Center, The University of Arizona College of Medicine, Phoenix, Arizona, USA.
| | - Balaji Tamarappoo
- Division of Cardiology, Banner University Medical Center, The University of Arizona College of Medicine, Phoenix, Arizona, USA
| | - Michael F Morris
- Division of Cardiology, Banner University Medical Center, The University of Arizona College of Medicine, Phoenix, Arizona, USA
| |
Collapse
|
10
|
Xu L, Zahid S, Khoshknab M, Moss J, Berger RD, Chrispin J, Callans D, Marchlinski FE, Zimmerman SL, Han Y, Desjardins B, Trayanova N, Nazarian S. Lipomatous Metaplasia Facilitates Slow Conduction in Critical Ventricular Tachycardia Corridors Within Postinfarct Myocardium. JACC Clin Electrophysiol 2023; 9:1235-1245. [PMID: 37227343 DOI: 10.1016/j.jacep.2023.02.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 02/10/2023] [Accepted: 02/15/2023] [Indexed: 05/26/2023]
Abstract
BACKGROUND Myocardial lipomatous metaplasia (LM) has been reported to be associated with post-infarct ventricular tachycardia (VT) circuitry. OBJECTIVES This study examined the association of scar versus LM composition with impulse conduction velocity (CV) in putative VT corridors that traverse the infarct zone in post-infarct patients. METHODS The cohort included 31 post-infarct patients from the prospective INFINITY (Intra-Myocardial Fat Deposition and Ventricular Tachycardia in Cardiomyopathy) study. Myocardial scar, border zone, and potential viable corridors were defined by late gadolinium enhancement cardiac magnetic resonance (LGE-CMR), and LM was defined by computed tomography. Images were registered to electroanatomic maps, and the CV at each electroanatomic map point was calculated as the mean CV between that point and 5 adjacent points along the activation wave front. RESULTS Regions with LM exhibited lower CV than scar (median = 11.9 vs 13.5 cm/s; P < 0.001). Of 94 corridors computed from LGE-CMR and electrophysiologically confirmed to participate in VT circuitry, 93 traversed through or near LM. These critical corridors displayed slower CV (median 8.8 [IQR: 5.9-15.7] cm/s vs 39.2 [IQR: 28.1-58.5]) cm/s; P < 0.001) than 115 noncritical corridors distant from LM. Additionally, critical corridors demonstrated low-peripheral, high-center (mountain shaped, 23.3%) or mean low-level (46.7%) CV patterns compared with 115 noncritical corridors distant from LM that displayed high-peripheral, low-center (valley shaped, 19.1%) or mean high-level (60.9%) CV patterns. CONCLUSIONS The association of myocardial LM with VT circuitry is at least partially mediated by slowing nearby corridor CV thus facilitating an excitable gap that enables circuit re-entry.
Collapse
Affiliation(s)
- Lingyu Xu
- Cardiovascular Medicine Division, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA.
| | - Sohail Zahid
- Department of Internal Medicine, New York University Langone Medical Center, New York, New York, USA
| | - Mirmilad Khoshknab
- Cardiovascular Medicine Division, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
| | - Juwann Moss
- Cardiovascular Medicine Division, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
| | - Ronald D Berger
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, USA; Department of Cardiology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Jonathan Chrispin
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, USA; Department of Cardiology, Johns Hopkins University, Baltimore, Maryland, USA
| | - David Callans
- Cardiovascular Medicine Division, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
| | - Francis E Marchlinski
- Cardiovascular Medicine Division, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
| | - Stefan L Zimmerman
- Department of Radiology and Radiological Sciences, Johns Hopkins University, Baltimore, Maryland, USA
| | - Yuchi Han
- Cardiovascular Medicine Division, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
| | - Benoit Desjardins
- Department of Radiology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
| | - Natalia Trayanova
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, USA
| | - Saman Nazarian
- Cardiovascular Medicine Division, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA. https://twitter.com/Dr_Nazarian_EP
| |
Collapse
|
11
|
Durkina AV, Szeiffova Bacova B, Bernikova OG, Gonotkov MA, Sedova KA, Cuprova J, Vaykshnorayte MA, Diez ER, Prado NJ, Azarov JE. Blockade of Melatonin Receptors Abolishes Its Antiarrhythmic Effect and Slows Ventricular Conduction in Rat Hearts. Int J Mol Sci 2023; 24:11931. [PMID: 37569306 PMCID: PMC10419066 DOI: 10.3390/ijms241511931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Revised: 07/17/2023] [Accepted: 07/22/2023] [Indexed: 08/13/2023] Open
Abstract
Melatonin has been reported to cause myocardial electrophysiological changes and prevent ventricular tachycardia or fibrillation (VT/VF) in ischemia and reperfusion. We sought to identify electrophysiological targets responsible for the melatonin antiarrhythmic action and to explore whether melatonin receptor-dependent pathways or its antioxidative properties are essential for these effects. Ischemia was induced in anesthetized rats given a placebo, melatonin, and/or luzindole (MT1/MT2 melatonin receptor blocker), and epicardial mapping with reperfusion VT/VFs assessment was performed. The oxidative stress assessment and Western blotting analysis were performed in the explanted hearts. Transmembrane potentials and ionic currents were recorded in cardiomyocytes with melatonin and/or luzindole application. Melatonin reduced reperfusion VT/VF incidence associated with local activation time in logistic regression analysis. Melatonin prevented ischemia-related conduction slowing and did not change the total connexin43 (Cx43) level or oxidative stress markers, but it increased the content of a phosphorylated Cx43 variant (P-Cx43368). Luzindole abolished the melatonin antiarrhythmic effect, slowed conduction, decreased total Cx43, protein kinase Cε and P-Cx43368 levels, and the IK1 current, and caused resting membrane potential (RMP) depolarization. Neither melatonin nor luzindole modified INa current. Thus, the antiarrhythmic effect of melatonin was mediated by the receptor-dependent enhancement of impulse conduction, which was associated with Cx43 phosphorylation and maintaining the RMP level.
Collapse
Affiliation(s)
- Aleksandra V. Durkina
- Department of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch of the Russian Academy of Sciences, 167982 Syktyvkar, Russia; (A.V.D.); (O.G.B.); (M.A.G.); (M.A.V.); (J.E.A.)
| | - Barbara Szeiffova Bacova
- Center of Experimental Medicine, Institute for Heart Research, Slovak Academy of Sciences, 81438 Bratislava, Slovakia
| | - Olesya G. Bernikova
- Department of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch of the Russian Academy of Sciences, 167982 Syktyvkar, Russia; (A.V.D.); (O.G.B.); (M.A.G.); (M.A.V.); (J.E.A.)
| | - Mikhail A. Gonotkov
- Department of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch of the Russian Academy of Sciences, 167982 Syktyvkar, Russia; (A.V.D.); (O.G.B.); (M.A.G.); (M.A.V.); (J.E.A.)
| | - Ksenia A. Sedova
- Department of Biomedical Technology, Faculty of Biomedical Engineering, Czech Technical University in Prague, 27201 Kladno, Czech Republic;
| | - Julie Cuprova
- Department of Health Care Disciplines and Population Protection, Faculty of Biomedical Engineering, Czech Technical University in Prague, 27201 Kladno, Czech Republic;
| | - Marina A. Vaykshnorayte
- Department of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch of the Russian Academy of Sciences, 167982 Syktyvkar, Russia; (A.V.D.); (O.G.B.); (M.A.G.); (M.A.V.); (J.E.A.)
| | - Emiliano R. Diez
- Instituto de Fisiología, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza 5500, Argentina; (E.R.D.); (N.J.P.)
| | - Natalia J. Prado
- Instituto de Fisiología, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza 5500, Argentina; (E.R.D.); (N.J.P.)
| | - Jan E. Azarov
- Department of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch of the Russian Academy of Sciences, 167982 Syktyvkar, Russia; (A.V.D.); (O.G.B.); (M.A.G.); (M.A.V.); (J.E.A.)
- Department of Biomedical Technology, Faculty of Biomedical Engineering, Czech Technical University in Prague, 27201 Kladno, Czech Republic;
| |
Collapse
|
12
|
Casolo A, Maeo S, Balshaw TG, Lanza MB, Martin NRW, Nuccio S, Moro T, Paoli A, Felici F, Maffulli N, Eskofier B, Kinfe TM, Folland JP, Farina D, Vecchio AD. Non-invasive estimation of muscle fibre size from high-density electromyography. J Physiol 2023; 601:1831-1850. [PMID: 36929484 DOI: 10.1113/jp284170] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Accepted: 03/13/2023] [Indexed: 03/18/2023] Open
Abstract
Because of the biophysical relation between muscle fibre diameter and the propagation velocity of action potentials along the muscle fibres, motor unit conduction velocity could be a non-invasive index of muscle fibre size in humans. However, the relation between motor unit conduction velocity and fibre size has been only assessed indirectly in animal models and in human patients with invasive intramuscular EMG recordings, or it has been mathematically derived from computer simulations. By combining advanced non-invasive techniques to record motor unit activity in vivo, i.e. high-density surface EMG, with the gold standard technique for muscle tissue sampling, i.e. muscle biopsy, here we investigated the relation between the conduction velocity of populations of motor units identified from the biceps brachii muscle, and muscle fibre diameter. We demonstrate the possibility of predicting muscle fibre diameter (R2 = 0.66) and cross-sectional area (R2 = 0.65) from conduction velocity estimates with low systematic bias (∼2% and ∼4% respectively) and a relatively low margin of individual error (∼8% and ∼16%, respectively). The proposed neuromuscular interface opens new perspectives in the use of high-density EMG as a non-invasive tool to estimate muscle fibre size without the need of surgical biopsy sampling. The non-invasive nature of high-density surface EMG for the assessment of muscle fibre size may be useful in studies monitoring child development, ageing, space and exercise physiology, although the applicability and validity of the proposed methodology need to be more directly assessed in these specific populations by future studies. KEY POINTS: Because of the biophysical relation between muscle fibre size and the propagation velocity of action potentials along the sarcolemma, motor unit conduction velocity could represent a potential non-invasive candidate for estimating muscle fibre size in vivo. This relation has been previously assessed in animal models and humans with invasive techniques, or it has been mathematically derived from simulations. By combining high-density surface EMG with muscle biopsy, here we explored the relation between the conduction velocity of populations of motor units and muscle fibre size in healthy individuals. Our results confirmed that motor unit conduction velocity can be considered as a novel biomarker of fibre size, which can be adopted to predict muscle fibre diameter and cross-sectional area with low systematic bias and margin of individual error. The proposed neuromuscular interface opens new perspectives in the use of high-density EMG as a non-invasive tool to estimate muscle fibre size without the need of surgical biopsy sampling.
Collapse
Affiliation(s)
- Andrea Casolo
- Department of Biomedical Sciences, University of Padova, Padua, Italy
| | - Sumiaki Maeo
- Faculty of Sport and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan
- School of Sport, Exercise & Health Sciences, Loughborough University, Loughborough, UK
| | - Thomas G Balshaw
- School of Sport, Exercise & Health Sciences, Loughborough University, Loughborough, UK
- Versus Arthritis Centre for Sport, Exercise and Osteoarthritis Research, Loughborough University, Leicestershire, UK
| | - Marcel B Lanza
- Department of Physical Therapy and Rehabilitation Science, University of Maryland, Baltimore, MD, USA
| | - Neil R W Martin
- Versus Arthritis Centre for Sport, Exercise and Osteoarthritis Research, Loughborough University, Leicestershire, UK
| | - Stefano Nuccio
- Department of Movement, Human and Health Sciences, University of Rome 'Foro Italico', Rome, Italy
| | - Tatiana Moro
- Department of Biomedical Sciences, University of Padova, Padua, Italy
| | - Antonio Paoli
- Department of Biomedical Sciences, University of Padova, Padua, Italy
| | - Francesco Felici
- Department of Movement, Human and Health Sciences, University of Rome 'Foro Italico', Rome, Italy
| | - Nicola Maffulli
- Department of Trauma and Orthopaedic Surgery, School Medicine, Surgery and Dentistry, University of Salerno, Salerno, Italy
- School of Pharmacy and Bioengineering, Keele University School of Medicine, Stoke on Trent, UK
- Queen Mary University of London, Barts and the London School of Medicine and Dentistry, Centre for Sports and Exercise Medicine, Mile End Hospital, London, UK
| | - Bjoern Eskofier
- Department Artificial Intelligence in Biomedical Engineering, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Thomas M Kinfe
- Department Artificial Intelligence in Biomedical Engineering, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Jonathan P Folland
- School of Sport, Exercise & Health Sciences, Loughborough University, Loughborough, UK
- Versus Arthritis Centre for Sport, Exercise and Osteoarthritis Research, Loughborough University, Leicestershire, UK
| | - Dario Farina
- Department of Bioengineering, Imperial College London, London, UK
| | - Alessandro Del Vecchio
- Department Artificial Intelligence in Biomedical Engineering, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| |
Collapse
|
13
|
Ciotu CI, Kistner K, Kaindl U, Millesi F, Weiss T, Radtke C, Kremer A, Schmidt K, Fischer MJM. Schwann cell stimulation induces functional and structural changes in peripheral nerves. Glia 2023; 71:945-956. [PMID: 36495059 DOI: 10.1002/glia.24316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 11/19/2022] [Accepted: 11/24/2022] [Indexed: 12/14/2022]
Abstract
Signal propagation is the essential function of nerves. Lysophosphatidic acid 18:1 (LPA) allows the selective stimulation of calcium signaling in Schwann cells but not neurons. Here, the time course of slowing and amplitude reduction on compound action potentials due to LPA exposure was observed in myelinated and unmyelinated fibers of the mouse, indicating a clear change of axonal function. Teased nerve fiber imaging showed that Schwann cell activation is also present in axon-attached Schwann cells in freshly isolated peripheral rat nerves. The LPA receptor 1 was primarily localized at the cell extensions in isolated rat Schwann cells, suggesting a role in cell migration. Structural investigation of rat C-fibers demonstrated that LPA leads to an evagination of the axons from their Schwann cells. In A-fibers, the nodes of Ranvier appeared unchanged, but the Schmidt-Lanterman incisures were shortened and myelination reduced. The latter might increase leak current, reducing the potential spread to the next node of Ranvier and explain the changes in conduction velocity. The observed structural changes provide a plausible explanation for the functional changes in myelinated and unmyelinated axons of peripheral nerves and the reported sensory sensations such as itch and pain.
Collapse
Affiliation(s)
- Cosmin I Ciotu
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Katrin Kistner
- Institute of Physiology and Pathophysiology, University of Erlangen-Nürnberg, Erlangen, Germany
| | - Ulrich Kaindl
- Department of Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Flavia Millesi
- Department of Plastic, Reconstructive and Aesthetic Surgery, Medical University of Vienna, Vienna, Austria
| | - Tamara Weiss
- Department of Plastic, Reconstructive and Aesthetic Surgery, Medical University of Vienna, Vienna, Austria
| | - Christine Radtke
- Department of Plastic, Reconstructive and Aesthetic Surgery, Medical University of Vienna, Vienna, Austria
| | - Andreas Kremer
- Department of Gastroenterology and Hepatology, University Hospital Zürich, Zürich, Switzerland
| | - Katy Schmidt
- Department of Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Michael J M Fischer
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| |
Collapse
|
14
|
Yamada S, Kaneshiro T, Nodera M, Amami K, Nehashi T, Takeishi Y. Left atrial epicardial adipose tissue exacerbates electrical conduction disturbance in normal-weight patients undergoing pulmonary vein isolation for atrial fibrillation. J Cardiovasc Electrophysiol 2023; 34:565-574. [PMID: 36571163 DOI: 10.1111/jce.15794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 12/04/2022] [Accepted: 12/20/2022] [Indexed: 12/27/2022]
Abstract
INTRODUCTION Epicardial adipose tissue (EAT) exacerbates both electrical and structural remodeling in obese atrial fibrillation (AF) patients, but the impacts of EAT on atrial arrhythmogenicity remain unclear in normal-weight AF patients. Therefore, we sought to investigate this issue using electroanatomic mapping. METHODS AND RESULTS We enrolled drug-refractory 105 paroxysmal AF patients in the normal body mass index range (18.5-24.9 kg/m2 ), who had undergone electroanatomic mapping after pulmonary vein isolation (PVI). One day before PVI, we assessed P-wave duration in a 12-lead electrocardiogram and left atrial (LA)-EAT volumes using contrast-enhanced computed tomography. The patients were divided into two groups based on the median LA-EAT volume (16.0 ml); the high LA-EAT group (≥16.0 ml, n = 53) and low LA-EAT group (<16.0 ml, n = 52). We compared P-wave duration, LA conduction velocity and bipolar voltage, the presence of low-voltage zone (<0.5 mV), and LA volume index on echocardiography between the two groups. The LA bipolar voltage, low-voltage zone, and LA volume index were not different between the high and low LA-EAT groups. However, P-wave duration was significantly longer in the high group than in the low group (p < .001). Additionally, the LA conduction velocity was significantly more depressed in the high group than in the low group (p < .001). Multivariate linear regression analysis revealed that LA-EAT volume was correlated with P-wave duration (β = .367, p < .001) and conduction velocity (β = -.566, p < .001), respectively. CONCLUSIONS Increased LA-EAT volumes were associated with electrical conduction disturbance after PVI in normal-weight patients with AF. P-wave duration may be a clinically useful predictor of LA-EAT.
Collapse
Affiliation(s)
- Shinya Yamada
- Department of Cardiovascular Medicine, Fukushima Medical University, Fukushima, Japan
| | - Takashi Kaneshiro
- Department of Cardiovascular Medicine, Fukushima Medical University, Fukushima, Japan.,Department of Arrhythmia and Cardiac Pacing, Fukushima Medical University, Fukushima, Japan
| | - Minoru Nodera
- Department of Cardiovascular Medicine, Fukushima Medical University, Fukushima, Japan
| | - Kazuaki Amami
- Department of Cardiovascular Medicine, Fukushima Medical University, Fukushima, Japan
| | - Takeshi Nehashi
- Department of Cardiovascular Medicine, Fukushima Medical University, Fukushima, Japan
| | - Yasuchika Takeishi
- Department of Cardiovascular Medicine, Fukushima Medical University, Fukushima, Japan
| |
Collapse
|
15
|
Lima da Silva G, Cortez-Dias N, Nunes Ferreira A, Nakar E, Francisco R, Pereira M, Moreno J, Martins RP, Pinto FJ, de Sousa J. Impact of different activation wavefronts on ischemic myocardial scar electrophysiological properties during high-density ventricular tachycardia mapping and ablation. J Cardiovasc Electrophysiol 2023; 34:389-399. [PMID: 36335623 DOI: 10.1111/jce.15740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 10/02/2022] [Accepted: 10/12/2022] [Indexed: 11/08/2022]
Abstract
INTRODUCTION Scar-related ventricular tachycardia (VT) usually results from an underlying reentrant circuit facilitated by anatomical and functional barriers. The later are sensitive to the direction of ventricular activation wavefronts. We aim to evaluate the impact of different ventricular activation wavefronts on the functional electrophysiological properties of myocardial tissue. METHODS Patients with ischemic heart disease referred for VT ablation underwent high-density mapping using Carto®3 (Biosense Webster). Maps were generated during sinus rhythm, right and left ventricular pacing, and analyzed using a new late potential map software, which allows to assess local conduction velocities and facilitates the delineation of intra-scar conduction corridors (ISCC); and for all stable VTs. RESULTS In 16 patients, 31 high-resolution substrate maps from different ventricular activation wavefronts and 7 VT activation maps were obtained. Local abnormal ventricular activities (LAVAs) were found in VT isthmus, but also in noncritical areas. The VT isthmus was localized in areas of LAVAs overlapping surface between the different activation wavefronts. The deceleration zone location differed depending on activation wavefronts. Sixty-six percent of ISCCs were similarly identified in all activating wavefronts, but the one acting as VT isthmus was simultaneously identified in all activation wavefronts in all cases. CONCLUSION Functional based substrate mapping may improve the specificity to localize the most arrhythmogenic regions within the scar, making the use of different activation wavefronts unnecessary in most cases.
Collapse
Affiliation(s)
- Gustavo Lima da Silva
- Cardiology Department, Santa Maria University Hospital (CHULN), Lisbon Academic Medical Centre, Lisbon, Portugal.,Cardiac Rhythm Abnormalities Unit, Cardiovascular Centre of the University of Lisbon, Lisbon School of Medicine of the Universidade de Lisboa, Lisbon, Portugal
| | - Nuno Cortez-Dias
- Cardiology Department, Santa Maria University Hospital (CHULN), Lisbon Academic Medical Centre, Lisbon, Portugal.,Cardiac Rhythm Abnormalities Unit, Cardiovascular Centre of the University of Lisbon, Lisbon School of Medicine of the Universidade de Lisboa, Lisbon, Portugal
| | - Afonso Nunes Ferreira
- Cardiology Department, Santa Maria University Hospital (CHULN), Lisbon Academic Medical Centre, Lisbon, Portugal.,Cardiac Rhythm Abnormalities Unit, Cardiovascular Centre of the University of Lisbon, Lisbon School of Medicine of the Universidade de Lisboa, Lisbon, Portugal
| | - Elad Nakar
- Research and Development Department, Biosense Webster, Johnson & Johnson, Yokneam, Israel
| | - Raquel Francisco
- Biosense Webster, Johnson & Johnson, EMEA Clinical Development, Diegem, Belgium
| | - Mariana Pereira
- Biosense Webster, Johnson & Johnson, Clinical Support, Porto Salvo, Portugal
| | - Javier Moreno
- Cardiology Department, Arrhythmia Unit, University Hospital Ramón y Cajal and CIBER-CV Madrid, Madrid, Spain
| | - Raphaël P Martins
- Department of Cardiology, Rennes University Hospital, Rennes, France
| | - Fausto J Pinto
- Cardiology Department, Santa Maria University Hospital (CHULN), Lisbon Academic Medical Centre, Lisbon, Portugal.,Cardiac Rhythm Abnormalities Unit, Cardiovascular Centre of the University of Lisbon, Lisbon School of Medicine of the Universidade de Lisboa, Lisbon, Portugal
| | - João de Sousa
- Cardiology Department, Santa Maria University Hospital (CHULN), Lisbon Academic Medical Centre, Lisbon, Portugal.,Cardiac Rhythm Abnormalities Unit, Cardiovascular Centre of the University of Lisbon, Lisbon School of Medicine of the Universidade de Lisboa, Lisbon, Portugal
| |
Collapse
|
16
|
Łach P. [Changes in neuromuscular conduction of workers depending on age]. Med Pr 2022; 73:417-425. [PMID: 36515224 DOI: 10.13075/mp.5893.01287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND The research was conducted to determine the effect of age on potential functional changes occurring through the transmission of nerve impulses in the motor nerves supplying selected muscles of the lower limb. The nerve conduction parameters in the lower limb were measured, as well as the ability to control muscle tension with pressure on the foot pedal. MATERIAL AND METHODS The study included a group of 54 men, differentiated by age. During the research, the speed of nerve conduction, amplitude and latency of the motor response in the tibial and peroneal nerves were measured. During the RAMP-contraction test, the EMG signal was recorded from the tibialis anterior muscles and the gastrocnemius muscles of the medial head. RESULTS The results of the research showed that with age the ability to control muscle tone decreases, the speed of transmission of electrical impulses decreases, the motor response is delayed and its amplitude is significantly lower than in the case of younger people. CONCLUSIONS The deterioration of neuromuscular conduction observed with age and a reduction in the ability to control the generated value of muscle strength may result in a deterioration of the ability to operate equipment or drive vehicles. From the point of view of prolonging the activity in working life, identifying all factors limiting the functioning of an older employee in the work environment may be the basis for creating guidelines and recommendations helpful in the design of devices and workstations for older employees. Med Pr. 2022;73(5):417-25.
Collapse
Affiliation(s)
- Patrycja Łach
- Centralny Instytut Ochrony Pracy - Państwowy Instytut Badawczy / Central Institute for Labour Protection - National Research Institute, Warsaw, Poland (Zakład Ergonomii / Department of Ergonomics)
| |
Collapse
|
17
|
Osanai Y, Yamazaki R, Shinohara Y, Ohno N. Heterogeneity and regulation of oligodendrocyte morphology. Front Cell Dev Biol 2022; 10:1030486. [PMID: 36393856 PMCID: PMC9644283 DOI: 10.3389/fcell.2022.1030486] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 10/10/2022] [Indexed: 09/24/2023] Open
Abstract
Oligodendrocytes form multiple myelin sheaths in the central nervous system (CNS), which increase nerve conduction velocity and are necessary for basic and higher brain functions such as sensory function, motor control, and learning. Structures of the myelin sheath such as myelin internodal length and myelin thickness regulate nerve conduction. Various parts of the central nervous system exhibit different myelin structures and oligodendrocyte morphologies. Recent studies supported that oligodendrocytes are a heterogenous population of cells and myelin sheaths formed by some oligodendrocytes can be biased to particular groups of axons, and myelin structures are dynamically modulated in certain classes of neurons by specific experiences. Structures of oligodendrocyte/myelin are also affected in pathological conditions such as demyelinating and neuropsychiatric disorders. This review summarizes our understanding of heterogeneity and regulation of oligodendrocyte morphology concerning central nervous system regions, neuronal classes, experiences, diseases, and how oligodendrocytes are optimized to execute central nervous system functions.
Collapse
Affiliation(s)
- Yasuyuki Osanai
- Department of Anatomy, Division of Histology and Cell Biology, School of Medicine, Jichi Medical University, Shimotsuke, Japan
- Australian Regenerative Medicine Institute, Monash University, Clayton, VIC, Australia
| | - Reiji Yamazaki
- Department of Anatomy, Division of Histology and Cell Biology, School of Medicine, Jichi Medical University, Shimotsuke, Japan
| | - Yoshiaki Shinohara
- Department of Anatomy, Division of Histology and Cell Biology, School of Medicine, Jichi Medical University, Shimotsuke, Japan
- Department of Anatomy and Cell Biology, Faculty of Medicine, University of Yamanashi, Chuo, Japan
| | - Nobuhiko Ohno
- Department of Anatomy, Division of Histology and Cell Biology, School of Medicine, Jichi Medical University, Shimotsuke, Japan
- Division of Ultrastructural Research, National Institute for Physiological Sciences, Okazaki, Japan
| |
Collapse
|
18
|
Basu K, Appukuttan S, Manchanda R, Sik A. Difference in axon diameter and myelin thickness between excitatory and inhibitory callosally projecting axons in mice. Cereb Cortex 2022; 33:4101-4115. [PMID: 36205478 PMCID: PMC10068302 DOI: 10.1093/cercor/bhac329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 07/18/2022] [Accepted: 08/02/2022] [Indexed: 11/13/2022] Open
Abstract
Synchronization of network oscillation in spatially distant cortical areas is essential for normal brain activity. Precision in synchronization between hemispheres depends on the axonal conduction velocity, which is determined by physical parameters of the axons involved, including diameter, and extent of myelination. To compare these parameters in long-projecting excitatory and inhibitory axons in the corpus callosum, we used genetically modified mice and virus tracing to separately label CaMKIIα expressing excitatory and GABAergic inhibitory axons. Using electron microscopy analysis, we revealed that (i) the axon diameters of excitatory fibers (myelinated axons) are significantly larger than those of nonmyelinated excitatory axons; (ii) the diameters of bare axons of excitatory myelinated fibers are significantly larger than those of their inhibitory counterparts; and (iii) myelinated excitatory fibers are significantly larger than myelinated inhibitory fibers. Also, the thickness of myelin ensheathing inhibitory axons is significantly greater than for excitatory axons, with the ultrastructure of the myelin around excitatory and inhibitory fibers also differing. We generated a computational model to investigate the functional consequences of these parameter divergences. Our simulations indicate that impulses through inhibitory and excitatory myelinated fibers reach the target almost simultaneously, whereas action potentials conducted by nonmyelinated axons reach target cells with considerable delay.
Collapse
Affiliation(s)
- Kaustuv Basu
- Facility for Electron Microscopy Research, McGill University, Montreal, QC H3A 0C72, Canada.,Department of Anatomy & Cell Biology, McGill University, Montreal, Canada
| | - Shailesh Appukuttan
- Biomedical Engineering Group, Department of Biosciences & Bioengineering IIT Bombay, Powai, Mumbay, 4000764, India
| | - Rohit Manchanda
- Biomedical Engineering Group, Department of Biosciences & Bioengineering IIT Bombay, Powai, Mumbay, 4000764, India
| | - Attila Sik
- College of Medical and Dental Sciences, University of Birmingham, Vincent Drive, Birmingham B15 2TT, United Kingdom.,Institute of Physiology, Medical School, University of Pecs, Pecs H-7624, Hungary.,Institute of Transdisciplinary Discoveries, Medical School, University of Pecs, Pecs H-7624, Hungary
| |
Collapse
|
19
|
Ogata G, Partida GJ, Fasoli A, Ishida AT. Calcium/calmodulin-dependent protein kinase II associates with the K + channel isoform Kv4.3 in adult rat optic nerve. Front Neuroanat 2022; 16:958986. [PMID: 36172564 PMCID: PMC9512010 DOI: 10.3389/fnana.2022.958986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 08/10/2022] [Indexed: 11/25/2022] Open
Abstract
Spikes are said to exhibit “memory” in that they can be altered by spikes that precede them. In retinal ganglion cell axons, for example, rapid spiking can slow the propagation of subsequent spikes. This increases inter-spike interval and, thus, low-pass filters instantaneous spike frequency. Similarly, a K+ ion channel blocker (4-aminopyridine, 4AP) increases the time-to-peak of compound action potentials recorded from optic nerve, and we recently found that reducing autophosphorylation of calcium/calmodulin-dependent protein kinase II (CaMKII) does too. These results would be expected if CaMKII modulates spike propagation by regulating 4AP-sensitive K+ channels. As steps toward identifying a possible substrate, we test whether (i) 4AP alters optic nerve spike shape in ways consistent with reducing K+ current, (ii) 4AP alters spike propagation consistent with effects of reducing CaMKII activation, (iii) antibodies directed against 4AP-sensitive and CaMKII-regulated K+ channels bind to optic nerve axons, and (iv) optic nerve CaMKII co-immunoprecipitates with 4AP-sensitive K+ channels. We find that, in adult rat optic nerve, (i) 4AP selectively slows spike repolarization, (ii) 4AP slows spike propagation, (iii) immunogen-blockable staining is achieved with anti-Kv4.3 antibodies but not with antibodies directed against Kv1.4 or Kv4.2, and (iv) CaMKII associates with Kv4.3. Kv4.3 may thus be a substrate that underlies activity-dependent spike regulation in adult visual system pathways.
Collapse
Affiliation(s)
- Genki Ogata
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, Davis, CA, United States
| | - Gloria J Partida
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, Davis, CA, United States
| | - Anna Fasoli
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, Davis, CA, United States
| | - Andrew T Ishida
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, Davis, CA, United States.,Department of Ophthalmology and Vision Science, University of California, Sacramento, Sacramento, CA, United States
| |
Collapse
|
20
|
Clark IA, Mohammadi S, Callaghan MF, Maguire EA. Conduction velocity along a key white matter tract is associated with autobiographical memory recall ability. eLife 2022; 11:79303. [PMID: 36166372 PMCID: PMC9514844 DOI: 10.7554/elife.79303] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 09/12/2022] [Indexed: 12/01/2022] Open
Abstract
Conduction velocity is the speed at which electrical signals travel along axons and is a crucial determinant of neural communication. Inferences about conduction velocity can now be made in vivo in humans using a measure called the magnetic resonance (MR) g-ratio. This is the ratio of the inner axon diameter relative to that of the axon plus the myelin sheath that encases it. Here, in the first application to cognition, we found that variations in MR g-ratio, and by inference conduction velocity, of the parahippocampal cingulum bundle were associated with autobiographical memory recall ability in 217 healthy adults. This tract connects the hippocampus with a range of other brain areas. We further observed that the association seemed to be with inner axon diameter rather than myelin content. The extent to which neurites were coherently organised within the parahippocampal cingulum bundle was also linked with autobiographical memory recall ability. Moreover, these findings were specific to autobiographical memory recall and were not apparent for laboratory-based memory tests. Our results offer a new perspective on individual differences in autobiographical memory recall ability, highlighting the possible influence of specific white matter microstructure features on conduction velocity when recalling detailed memories of real-life past experiences.
Collapse
Affiliation(s)
- Ian A Clark
- Wellcome Centre for Human Neuroimaging, Department of Imaging Neuroscience, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - Siawoosh Mohammadi
- Institute of Systems Neuroscience, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
| | - Martina F Callaghan
- Wellcome Centre for Human Neuroimaging, Department of Imaging Neuroscience, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - Eleanor A Maguire
- Wellcome Centre for Human Neuroimaging, Department of Imaging Neuroscience, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom
| |
Collapse
|
21
|
Biendarra‐Tiegs SM, Yechikov S, Shergill B, Brumback B, Takahashi K, Shirure VS, Gonzalez RE, Houshmand L, Zhong D, Weng K, Silva J, Smith TW, Rentschler SL, George SC. An iPS-derived in vitro model of human atrial conduction. Physiol Rep 2022; 10:e15407. [PMID: 36117385 PMCID: PMC9483613 DOI: 10.14814/phy2.15407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Revised: 04/27/2022] [Accepted: 07/14/2022] [Indexed: 11/25/2022] Open
Abstract
Atrial fibrillation (AF) is the most common arrhythmia in the United States, affecting approximately 1 in 10 adults, and its prevalence is expected to rise as the population ages. Treatment options for AF are limited; moreover, the development of new treatments is hindered by limited (1) knowledge regarding human atrial electrophysiological endpoints (e.g., conduction velocity [CV]) and (2) accurate experimental models. Here, we measured the CV and refractory period, and subsequently calculated the conduction wavelength, in vivo (four subjects with AF and four controls), and ex vivo (atrial slices from human hearts). Then, we created an in vitro model of human atrial conduction using induced pluripotent stem (iPS) cells. This model consisted of iPS-derived human atrial cardiomyocytes plated onto a micropatterned linear 1D spiral design of Matrigel. The CV (34-41 cm/s) of the in vitro model was nearly five times faster than 2D controls (7-9 cm/s) and similar to in vivo (40-64 cm/s) and ex vivo (28-51 cm/s) measurements. Our iPS-derived in vitro model recapitulates key features of in vivo atrial conduction and may be a useful methodology to enhance our understanding of AF and model patient-specific disease.
Collapse
Affiliation(s)
| | - Sergey Yechikov
- Department of Biomedical EngineeringUniversity of California, DavisDavisCaliforniaUSA
| | - Bhupinder Shergill
- Department of Biomedical EngineeringUniversity of California, DavisDavisCaliforniaUSA
| | - Brittany Brumback
- Department of Biomedical EngineeringWashington University in St. LouisSt. LouisMissouriUSA
| | - Kentaro Takahashi
- Department of MedicineWashington University in St. LouisSt. LouisMissouriUSA
| | - Venktesh S. Shirure
- Department of Biomedical EngineeringUniversity of California, DavisDavisCaliforniaUSA
| | - Ruth Estelle Gonzalez
- Department of Biomedical EngineeringUniversity of California, DavisDavisCaliforniaUSA
| | - Laura Houshmand
- Department of Biomedical EngineeringUniversity of California, DavisDavisCaliforniaUSA
| | - Denise Zhong
- Department of Biomedical EngineeringUniversity of California, DavisDavisCaliforniaUSA
| | - Kuo‐Chan Weng
- Department of Biomedical EngineeringWashington University in St. LouisSt. LouisMissouriUSA
| | - Jon Silva
- Department of Biomedical EngineeringWashington University in St. LouisSt. LouisMissouriUSA
| | - Timothy W. Smith
- Department of MedicineWashington University in St. LouisSt. LouisMissouriUSA
| | - Stacey L. Rentschler
- Department of MedicineWashington University in St. LouisSt. LouisMissouriUSA
- Department of Developmental BiologyWashington University in St. LouisSt. LouisMissouriUSA
| | - Steven C. George
- Department of Biomedical EngineeringUniversity of California, DavisDavisCaliforniaUSA
| |
Collapse
|
22
|
Durkina AV, Bernikova OG, Gonotkov MA, Mikhaleva NJ, Sedova KA, Malykhina IA, Kuzmin VS, Velegzhaninov IO, Azarov JE. Melatonin treatment improves ventricular conduction via upregulation of Nav1.5 channel proteins and sodium current in the normal rat heart. J Pineal Res 2022; 73:e12798. [PMID: 35384053 DOI: 10.1111/jpi.12798] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 03/31/2022] [Accepted: 04/02/2022] [Indexed: 11/29/2022]
Abstract
Melatonin treatment was reported to reduce the risk of cardiac arrhythmias, and crucial for this antiarrhythmic action was the effect of melatonin on activation spread. The aim of the present study was evaluation of the mechanisms of this activation enhancement. Experiments were performed in a total of 123 control and melatonin-treated (10 mg/kg, daily, for 7 days) male Wistar rats. In epicardial mapping studies (64 leads, interlead distance 0.5 mm) in the anesthetized animals, activation times (ATs) were determined in each lead as dV/dt minimum during QRS complex under sinus rhythm. Epicardial pacing was performed to measure conduction velocity (CV) across the mapped area. Average left ventricular ATs were shorter in the treated animals as compared to the controls, whereas the minimal epicardial ATs indicating the duration of activation propagation via the ventricular conduction system did not differ between the groups. CV was higher in the treated groups indicating that melatonin affected conduction via contractile myocardium The area of Cx43-derived fluorescence, as well as the expression of Cx43 protein, was similar in ventricles in the control and melatonin-treated groups. Expression of Gja1 gene transcripts encoding Cx43, was increased in the last group. An uncoupling agent octanol modified myocardial conduction properties (time of activation, action potential upstroke velocity, passive electrotonic phase duration) similarly in both groups. On the other hand, the expression of both Scn5a gene transcripts encoding Nav1.5 proteins, as well as peak density of transmembrane sodium current were increased in the ventricular myocytes from the melatonin-treated animals. Thus, a week-long melatonin treatment caused the increase of conduction velocity via enhancement of sodium channel proteins expression and increase of sodium current in the ventricular myocytes.
Collapse
Affiliation(s)
- Aleksandra V Durkina
- Department of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
| | - Olesya G Bernikova
- Department of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
| | - Mikhail A Gonotkov
- Department of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
| | - Natalia J Mikhaleva
- Department of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
| | - Ksenia A Sedova
- Department of Biomedical Technology, Faculty of Biomedical Engineering, Czech Technical University in Prague, Kladno, Czech Republic
| | - Inna A Malykhina
- Department of Human and Animal Physiology, Biological Faculty, Lomonosov Moscow State University, Moscow, Russia
| | - Vladislav S Kuzmin
- Department of Human and Animal Physiology, Biological Faculty, Lomonosov Moscow State University, Moscow, Russia
| | - Ilya O Velegzhaninov
- Department of Radioecology, Institute of Biology, Komi Scientific Centre, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
| | - Jan E Azarov
- Department of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
| |
Collapse
|
23
|
Campanini I, Merlo A, Disselhorst-Klug C, Mesin L, Muceli S, Merletti R. Fundamental Concepts of Bipolar and High-Density Surface EMG Understanding and Teaching for Clinical, Occupational, and Sport Applications: Origin, Detection, and Main Errors. Sensors (Basel) 2022; 22:4150. [PMID: 35684769 PMCID: PMC9185290 DOI: 10.3390/s22114150] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 05/20/2022] [Accepted: 05/26/2022] [Indexed: 06/15/2023]
Abstract
Surface electromyography (sEMG) has been the subject of thousands of scientific articles, but many barriers limit its clinical applications. Previous work has indicated that the lack of time, competence, training, and teaching is the main barrier to the clinical application of sEMG. This work follows up and presents a number of analogies, metaphors, and simulations using physical and mathematical models that provide tools for teaching sEMG detection by means of electrode pairs (1D signals) and electrode grids (2D and 3D signals). The basic mechanisms of sEMG generation are summarized and the features of the sensing system (electrode location, size, interelectrode distance, crosstalk, etc.) are illustrated (mostly by animations) with examples that teachers can use. The most common, as well as some potential, applications are illustrated in the areas of signal presentation, gait analysis, the optimal injection of botulinum toxin, neurorehabilitation, ergonomics, obstetrics, occupational medicine, and sport sciences. The work is primarily focused on correct sEMG detection and on crosstalk. Issues related to the clinical transfer of innovations are also discussed, as well as the need for training new clinical and/or technical operators in the field of sEMG.
Collapse
Affiliation(s)
- Isabella Campanini
- LAM-Motion Analysis Laboratory, Neuromotor and Rehabilitation Department, S. Sebastiano Hospital, Azienda USL-IRCCS di Reggio Emilia, Via Circondaria 29, 42015 Correggio, Italy; (I.C.); or (A.M.)
| | - Andrea Merlo
- LAM-Motion Analysis Laboratory, Neuromotor and Rehabilitation Department, S. Sebastiano Hospital, Azienda USL-IRCCS di Reggio Emilia, Via Circondaria 29, 42015 Correggio, Italy; (I.C.); or (A.M.)
- Merlo Bioengineering, 43121 Parma, Italy
| | - Catherine Disselhorst-Klug
- Department of Rehabilitation & Prevention Engineering, Institute of Applied Medical Engineering, RWTH Aachen University, Pauwelsstr. 20, 52074 Aachen, Germany;
| | - Luca Mesin
- Mathematical Biology and Physiology Group, Department of Electronics and Telecommunications, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Turin, Italy;
| | - Silvia Muceli
- Division of Signal Processing and Biomedical Engineering, Department of Electrical Engineering, Chalmers University of Technology, Hörsalsvägen 11, 41296 Gothenburg, Sweden;
| | - Roberto Merletti
- Laboratory for Engineering of the Neuromuscular System (LISiN), Department of Electronics and Telecommunications, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Turin, Italy
| |
Collapse
|
24
|
Woodworth LA, Cansız B, Kaliske M. Balancing conduction velocity error in cardiac electrophysiology using a modified quadrature approach. Int J Numer Method Biomed Eng 2022; 38:e3589. [PMID: 35266643 DOI: 10.1002/cnm.3589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 01/20/2022] [Accepted: 02/28/2022] [Indexed: 06/14/2023]
Abstract
Conduction velocity error is often the main culprit behind the need for very fine spatial discretizations and high computational effort in cardiac electrophysiology problems. In light of this, a novel approach for simulating an accurate conduction velocity in coarse meshes with linear elements is suggested based on a modified quadrature approach. In this approach, the quadrature points are placed at arbitrary offsets of the isoparametric coordinates. A numerical study illustrates the dependence of the conduction velocity on the spatial discretization and the conductivity when using different quadrature rules and calculation approaches. Additionally, examples using the modified quadrature in coarse meshes for wave propagation demonstrate the improved accuracy of the conduction velocity with this method. This novel approach possesses great potential in reducing the computational effort required but remains limited to specific linear elements and experiences a reduction in accuracy for irregular meshes and heterogeneous conductivities. Further research can focus on developing an adaptive quadrature and extending the approach to other element formulations in order to make the approach more generally applicable.
Collapse
Affiliation(s)
- Lucas A Woodworth
- Institute for Structural Analysis, Technische Universität Dresden, Dresden, Germany
| | - Barış Cansız
- Institute for Structural Analysis, Technische Universität Dresden, Dresden, Germany
| | - Michael Kaliske
- Institute for Structural Analysis, Technische Universität Dresden, Dresden, Germany
| |
Collapse
|
25
|
Hawson J, Anderson RD, Al-Kaisey A, Chieng D, Segan L, Watts T, Campbell T, Morton J, McLellan A, Kistler P, Voskoboinik A, Pathik B, Kumar S, Kalman J, Lee G. Functional Assessment of Ventricular Tachycardia Circuits and Their Underlying Substrate Using Automated Conduction Velocity Mapping. JACC Clin Electrophysiol 2022; 8:480-494. [PMID: 35450603 DOI: 10.1016/j.jacep.2021.12.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 11/03/2021] [Accepted: 12/17/2021] [Indexed: 11/16/2022]
Abstract
OBJECTIVES This study sought to describe the utility of automated conduction velocity mapping (ACVM) in ventricular tachycardia (VT) ablation. BACKGROUND Identification of areas of slowed conduction velocity (CV) is critical to our understanding of VT circuits and their underlying substrate. Recently, an ACVM called Coherent Mapping (Biosense Webster Inc) has been developed for atrial mapping. However, its utility in VT mapping has not been described. METHODS Patients with paired high-density VT activation and substrate maps were included. ACVM was applied to paired VT activation and substrate maps to assess regional CV and activation patterns. A combination of ACVM, traditional local activation time maps, electrogram analysis, and off-line calculated CV using triangulation were used to characterize zones of slowed conduction during VT and in substrate mapping. RESULTS Fifteen patients were included in the study. In all cases, ACVM identified slow CV within the putative VT isthmus, which colocalized to the VT isthmus identified with entrainment. The dimensions of the VT isthmus with local activation time mapping were 37.8 ± 13.7 mm long and 8.7 ± 4.2 mm wide. In comparison, ACVM produced an isthmus that was shorter (length: 25.1 ± 10.6 mm; mean difference: 12.8; 95% CI: 7.5-18.0; P < 0.01) and wider (width: 18.8 ± 8.1 mm; mean difference: 10.1; 95% CI: 6.1-14.2; P < 0.01). In VT, the CV using triangulation at the entrance (8.0 ± 3.6 cm/s) and midisthmus (8.1 ± 4.3 cm/s) was not significantly different (P = 0.92) but was significantly faster at the exit (16.2 ± 9.7 cm/s; P < 0.01). In the paired substrate analysis, traditional local activation time isochronal mapping identified 6.3 ± 2.0 deceleration zones. In contrast, ACVM identified a median of 0 deceleration zones (IQR: 0-1; P < 0.01). CONCLUSIONS ACVM is a novel complementary tool that can be used to accurately resolve complex VT circuits and identify slow conduction zones in VT but has limited accuracy in identifying slowed conduction during substrate-based mapping.
Collapse
Affiliation(s)
- Joshua Hawson
- Department of Cardiology, Royal Melbourne Hospital, Melbourne, Victoria, Australia; Faculty of Medicine, Dentistry, and Health Science, University of Melbourne, Melbourne, Victoria, Australia
| | - Robert D Anderson
- Department of Cardiology, Royal Melbourne Hospital, Melbourne, Victoria, Australia; Faculty of Medicine, Dentistry, and Health Science, University of Melbourne, Melbourne, Victoria, Australia
| | - Ahmed Al-Kaisey
- Department of Cardiology, Royal Melbourne Hospital, Melbourne, Victoria, Australia; Faculty of Medicine, Dentistry, and Health Science, University of Melbourne, Melbourne, Victoria, Australia
| | - David Chieng
- Faculty of Medicine, Dentistry, and Health Science, University of Melbourne, Melbourne, Victoria, Australia; Department of Cardiology, The Alfred Hospital, Melbourne, Victoria, Australia
| | - Louise Segan
- Faculty of Medicine, Dentistry, and Health Science, University of Melbourne, Melbourne, Victoria, Australia; Department of Cardiology, The Alfred Hospital, Melbourne, Victoria, Australia
| | - Troy Watts
- Department of Cardiology, Royal Melbourne Hospital, Melbourne, Victoria, Australia
| | - Timothy Campbell
- Faculty of Medicine and Health, Western Clinical School, The University of Sydney, Sydney, New South Wales, Australia
| | - Joseph Morton
- Department of Cardiology, Royal Melbourne Hospital, Melbourne, Victoria, Australia
| | - Alexander McLellan
- Department of Cardiology, Royal Melbourne Hospital, Melbourne, Victoria, Australia
| | - Peter Kistler
- Faculty of Medicine, Dentistry, and Health Science, University of Melbourne, Melbourne, Victoria, Australia; Department of Cardiology, The Alfred Hospital, Melbourne, Victoria, Australia
| | - Aleksander Voskoboinik
- Faculty of Medicine, Dentistry, and Health Science, University of Melbourne, Melbourne, Victoria, Australia; Department of Cardiology, The Alfred Hospital, Melbourne, Victoria, Australia
| | - Bhupesh Pathik
- Department of Cardiology, Royal Melbourne Hospital, Melbourne, Victoria, Australia
| | - Saurabh Kumar
- Department of Cardiology, Westmead Hospital and Westmead Applied Research Centre, Westmead, New South Wales, Australia; Faculty of Medicine and Health, Western Clinical School, The University of Sydney, Sydney, New South Wales, Australia
| | - Jonathan Kalman
- Department of Cardiology, Royal Melbourne Hospital, Melbourne, Victoria, Australia; Faculty of Medicine, Dentistry, and Health Science, University of Melbourne, Melbourne, Victoria, Australia
| | - Geoffrey Lee
- Department of Cardiology, Royal Melbourne Hospital, Melbourne, Victoria, Australia; Faculty of Medicine, Dentistry, and Health Science, University of Melbourne, Melbourne, Victoria, Australia.
| |
Collapse
|
26
|
Cortez-Dias N, da Silva GL, Ferreira AN, Nakar E, Francisco R, Pereira M, Carpinteiro L, Pinto FJ, de Sousa J. NOVEL "LATE POTENTIAL MAP" ALGORITHM: ABNORMAL POTENTIALS AND SCAR CHANNELS DETECTION FOR VENTRICULAR TACHYCARDIA ABLATION. J Cardiovasc Electrophysiol 2022; 33:1211-1222. [PMID: 35338745 DOI: 10.1111/jce.15470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 01/27/2022] [Accepted: 03/19/2022] [Indexed: 11/28/2022]
Abstract
BACKGROUND Automated systems for substrate mapping in context of ventricular tachycardia (VT) ablation may annotate far-field rather than near-field signals, rendering the resulting maps hard to interpret. Additionally, quantitative assessment of local conduction velocity (LCV) remains an unmet need in clinical practice. We evaluate whether a new Late Potential Map (LPM) algorithm can provide an automatic and reliable annotation and localized bipolar voltage measurement of ventricular electrograms, and if LCV analysis allows to recognize intra-scar conduction corridors acting as VT isthmuses. METHODS In 16 patients referred for scar-related VT ablation, 8 VT activation maps and 29 high-resolution substrate maps from different activation wavefronts were obtained. In offline analysis, the LPM algorithm was compared to manually annotated substrate maps. Locations of the VT isthmuses were compared with the corresponding substrate maps in regard to LCV. RESULTS The LPM algorithm had an overall/local abnormal ventricular activity (LAVA) annotation accuracy of 94.5%/81.1%, which compares to 83.7%/23.9% for the previous Wavefront algorithm. The resultant maps presented a spatial concordance of 88.1% in delineating regions displaying local abnormal ventricular activity (LAVA). LAVA median localized bipolar voltage was 0.22 mV, but voltage amplitude assessment had modest accuracy in distinguishing LAVA from other abnormal electrograms (AUC:0.676; p<0.001). LCV analysis in high-density substrate maps identified a median of 2 intra-scar conduction corridors per patient (IQR: 2-3), including the one acting as VT isthmus in all cases. CONCLUSION The new LPM algorithm and LCV analysis may enhance substrate characterization in scar-related VT. This article is protected by copyright. All rights reserved.
Collapse
Affiliation(s)
- Nuno Cortez-Dias
- Cardiology Department, Santa Maria University Hospital (CHULN), Lisbon Academic Medical Centre, Lisbon, Portugal.,Cardiovascular Centre of the University of Lisbon, Lisbon School of Medicine of the Universidade de Lisboa, Lisbon, Portugal
| | - Gustavo Lima da Silva
- Cardiology Department, Santa Maria University Hospital (CHULN), Lisbon Academic Medical Centre, Lisbon, Portugal.,Cardiovascular Centre of the University of Lisbon, Lisbon School of Medicine of the Universidade de Lisboa, Lisbon, Portugal
| | - Afonso Nunes Ferreira
- Cardiology Department, Santa Maria University Hospital (CHULN), Lisbon Academic Medical Centre, Lisbon, Portugal.,Cardiovascular Centre of the University of Lisbon, Lisbon School of Medicine of the Universidade de Lisboa, Lisbon, Portugal
| | - Elad Nakar
- Biosense Webster, Johnson & Johnson, Research and Development Department, Yokneam, Israel
| | - Raquel Francisco
- Biosense Webster, Johnson & Johnson, EMEA Clinical Development, Diegem, Belgium
| | - Mariana Pereira
- Biosense Webster, Johnson & Johnson, Clinical Support, Porto Salvo, Portugal
| | - Luís Carpinteiro
- Cardiology Department, Santa Maria University Hospital (CHULN), Lisbon Academic Medical Centre, Lisbon, Portugal.,Cardiovascular Centre of the University of Lisbon, Lisbon School of Medicine of the Universidade de Lisboa, Lisbon, Portugal
| | - Fausto J Pinto
- Cardiology Department, Santa Maria University Hospital (CHULN), Lisbon Academic Medical Centre, Lisbon, Portugal.,Cardiovascular Centre of the University of Lisbon, Lisbon School of Medicine of the Universidade de Lisboa, Lisbon, Portugal
| | - João de Sousa
- Cardiology Department, Santa Maria University Hospital (CHULN), Lisbon Academic Medical Centre, Lisbon, Portugal.,Cardiovascular Centre of the University of Lisbon, Lisbon School of Medicine of the Universidade de Lisboa, Lisbon, Portugal
| |
Collapse
|
27
|
Masè M, Cristoforetti A, Del Greco M, Ravelli F. A Divergence-Based Approach for the Identification of Atrial Fibrillation Focal Drivers From Multipolar Mapping: A Computational Study. Front Physiol 2021; 12:749430. [PMID: 35002755 PMCID: PMC8740027 DOI: 10.3389/fphys.2021.749430] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 11/30/2021] [Indexed: 11/13/2022] Open
Abstract
The expanding role of catheter ablation of atrial fibrillation (AF) has stimulated the development of novel mapping strategies to guide the procedure. We introduce a novel approach to characterize wave propagation and identify AF focal drivers from multipolar mapping data. The method reconstructs continuous activation patterns in the mapping area by a radial basis function (RBF) interpolation of multisite activation time series. Velocity vector fields are analytically determined, and the vector field divergence is used as a marker of focal drivers. The method was validated in a tissue patch cellular automaton model and in an anatomically realistic left atrial (LA) model with Courtemanche-Ramirez-Nattel ionic dynamics. Divergence analysis was effective in identifying focal drivers in a complex simulated AF pattern. Localization was reliable even with consistent reduction (47%) in the number of mapping points and in the presence of activation time misdetections (noise <10% of the cycle length). Proof-of-concept application of the method to human AF mapping data showed that divergence analysis consistently detected focal activation in the pulmonary veins and LA appendage area. These results suggest the potential of divergence analysis in combination with multipolar mapping to identify AF critical sites. Further studies on large clinical datasets may help to assess the clinical feasibility and benefit of divergence analysis for the optimization of ablation treatment.
Collapse
Affiliation(s)
- Michela Masè
- Laboratory of Biophysics and Translational Cardiology, Department of Cellular, Computational and Integrative Biology – CIBIO, University of Trento, Trento, Italy
- Institute of Mountain Emergency Medicine, EURAC Research, Bolzano, Italy
| | - Alessandro Cristoforetti
- Laboratory of Biophysics and Translational Cardiology, Department of Cellular, Computational and Integrative Biology – CIBIO, University of Trento, Trento, Italy
| | - Maurizio Del Greco
- Division of Cardiology, Santa Maria del Carmine Hospital, Rovereto, Italy
| | - Flavia Ravelli
- Laboratory of Biophysics and Translational Cardiology, Department of Cellular, Computational and Integrative Biology – CIBIO, University of Trento, Trento, Italy
- CISMed – Centre for Medical Sciences, University of Trento, Trento, Italy
| |
Collapse
|
28
|
Rodriguez-Falces J, Place N. Sarcolemmal Excitability, M-Wave Changes, and Conduction Velocity During a Sustained Low-Force Contraction. Front Physiol 2021; 12:732624. [PMID: 34721063 PMCID: PMC8554155 DOI: 10.3389/fphys.2021.732624] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 09/14/2021] [Indexed: 11/20/2022] Open
Abstract
This study was undertaken to investigate whether sarcolemmal excitability is impaired during a sustained low-force contraction [10% maximal voluntary contraction (MVC)] by assessing muscle conduction velocity and also by analyzing separately the first and second phases of the muscle compound action potential (M wave). Twenty-one participants sustained an isometric knee extension of 10% MVC for 3min. M waves were evoked by supramaximal single shocks to the femoral nerve given at 10-s intervals. The amplitude, duration, and area of the first and second M-wave phases were computed. Muscle fiber conduction velocity, voluntary surface electromyographic (EMG), perceived effort, MVC force, peak twitch force, and temperature were also recorded. The main findings were: (1) During the sustained contraction, conduction velocity remained unchanged. (2) The amplitude of the M-wave first phase decreased for the first ~30s (−7%, p<0.05) and stabilized thereafter, whereas the second phase amplitude increased for the initial ~30s (+7%, p<0.05), before stabilizing. (3) Both duration and area decreased steeply during the first ~30s, and then more gradually for the rest of the contraction. (4) During the sustained contraction, perceived effort increased fivefold, whereas knee extension EMG increased by ~10%. (5) Maximal voluntary force and peak twitch force decreased (respectively, −9% and −10%, p<0.05) after the low-force contraction. Collectively, the present results indicate that sarcolemmal excitability is well preserved during a sustained 10% MVC task. A depression of the M-wave first phase during a low-force contraction can occur even in the absence of changes in membrane excitability. The development of fatigue during a low-force contraction can occur without alteration of membrane excitability.
Collapse
Affiliation(s)
- Javier Rodriguez-Falces
- Department of Electrical and Electronical Engineering, Public University of Navarre, Pamplona, Spain
| | - Nicolas Place
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| |
Collapse
|
29
|
Han B, Trew ML, Zgierski-Johnston CM. Cardiac Conduction Velocity, Remodeling and Arrhythmogenesis. Cells 2021; 10:cells10112923. [PMID: 34831145 PMCID: PMC8616078 DOI: 10.3390/cells10112923] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 10/14/2021] [Accepted: 10/22/2021] [Indexed: 02/06/2023] Open
Abstract
Cardiac electrophysiological disorders, in particular arrhythmias, are a key cause of morbidity and mortality throughout the world. There are two basic requirements for arrhythmogenesis: an underlying substrate and a trigger. Altered conduction velocity (CV) provides a key substrate for arrhythmogenesis, with slowed CV increasing the probability of re-entrant arrhythmias by reducing the length scale over which re-entry can occur. In this review, we examine methods to measure cardiac CV in vivo and ex vivo, discuss underlying determinants of CV, and address how pathological variations alter CV, potentially increasing arrhythmogenic risk. Finally, we will highlight future directions both for methodologies to measure CV and for possible treatments to restore normal CV.
Collapse
Affiliation(s)
- Bo Han
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg-Bad Krozingen, 79110 Freiburg im Breisgau, Germany;
- Faculty of Medicine, University of Freiburg, 79110 Freiburg im Breisgau, Germany
- Spemann Graduate School of Biology and Medicine (SGBM), University of Freiburg, 79104 Freiburg im Breisgau, Germany
- Department of Cardiovascular Surgery, The Fourth People’s Hospital of Jinan, 250031 Jinan, China
| | - Mark L. Trew
- Auckland Bioengineering Institute, University of Auckland, Auckland 1010, New Zealand;
| | - Callum M. Zgierski-Johnston
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg-Bad Krozingen, 79110 Freiburg im Breisgau, Germany;
- Faculty of Medicine, University of Freiburg, 79110 Freiburg im Breisgau, Germany
- Correspondence:
| |
Collapse
|
30
|
Sankarankutty AC, Greiner J, Bragard J, Visker JR, Shankar TS, Kyriakopoulos CP, Drakos SG, Sachse FB. Etiology-Specific Remodeling in Ventricular Tissue of Heart Failure Patients and Its Implications for Computational Modeling of Electrical Conduction. Front Physiol 2021; 12:730933. [PMID: 34675817 PMCID: PMC8523803 DOI: 10.3389/fphys.2021.730933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 09/07/2021] [Indexed: 11/13/2022] Open
Abstract
With an estimated 64.3 million cases worldwide, heart failure (HF) imposes an enormous burden on healthcare systems. Sudden death from arrhythmia is the major cause of mortality in HF patients. Computational modeling of the failing heart provides insights into mechanisms of arrhythmogenesis, risk stratification of patients, and clinical treatment. However, the lack of a clinically informed approach to model cardiac tissues in HF hinders progress in developing patient-specific strategies. Here, we provide a microscopy-based foundation for modeling conduction in HF tissues. We acquired 2D images of left ventricular tissues from HF patients (n = 16) and donors (n = 5). The composition and heterogeneity of fibrosis were quantified at a sub-micrometer resolution over an area of 1 mm2. From the images, we constructed computational bidomain models of tissue electrophysiology. We computed local upstroke velocities of the membrane voltage and anisotropic conduction velocities (CV). The non-myocyte volume fraction was higher in HF than donors (39.68 ± 14.23 vs. 22.09 ± 2.72%, p < 0.01), and higher in ischemic (IC) than nonischemic (NIC) cardiomyopathy (47.2 ± 16.18 vs. 32.16 ± 6.55%, p < 0.05). The heterogeneity of fibrosis within each subject was highest for IC (27.1 ± 6.03%) and lowest for donors (7.47 ± 1.37%) with NIC (15.69 ± 5.76%) in between. K-means clustering of this heterogeneity discriminated IC and NIC with an accuracy of 81.25%. The heterogeneity in CV increased from donor to NIC to IC tissues. CV decreased with increasing fibrosis for longitudinal (R 2 = 0.28, p < 0.05) and transverse conduction (R 2 = 0.46, p < 0.01). The tilt angle of the CV vectors increased 2.1° for longitudinal and 0.91° for transverse conduction per 1% increase in fibrosis. Our study suggests that conduction fundamentally differs in the two etiologies due to the characteristics of fibrosis. Our study highlights the importance of the etiology-specific modeling of HF tissues and integration of medical history into electrophysiology models for personalized risk stratification and treatment planning.
Collapse
Affiliation(s)
- Aparna C Sankarankutty
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT, United States.,Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, United States
| | - Joachim Greiner
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg⋅Bad Krozingen, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Jean Bragard
- Department of Physics and Applied Mathematics, School of Sciences, University of Navarra, Pamplona, Spain
| | - Joseph R Visker
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT, United States.,Division of Cardiovascular Medicine, University of Utah School of Medicine, Salt Lake City, UT, United States
| | - Thirupura S Shankar
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT, United States.,Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, United States
| | - Christos P Kyriakopoulos
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT, United States.,Division of Cardiovascular Medicine, University of Utah School of Medicine, Salt Lake City, UT, United States
| | - Stavros G Drakos
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT, United States.,Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, United States.,Division of Cardiovascular Medicine, University of Utah School of Medicine, Salt Lake City, UT, United States
| | - Frank B Sachse
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT, United States.,Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, United States
| |
Collapse
|
31
|
Mei R, Huang L, Wu M, Jiang C, Yang A, Tao H, Zheng K, Yang J, Shen W, Chen X, Zhao X, Qiu M. Evidence That ITPR2-Mediated Intracellular Calcium Release in Oligodendrocytes Regulates the Development of Carbonic Anhydrase II + Type I/II Oligodendrocytes and the Sizes of Myelin Fibers. Front Cell Neurosci 2021; 15:751439. [PMID: 34630045 PMCID: PMC8492996 DOI: 10.3389/fncel.2021.751439] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Accepted: 09/03/2021] [Indexed: 11/13/2022] Open
Abstract
Myelination of neuronal axons in the central nervous system (CNS) by oligodendrocytes (OLs) enables rapid saltatory conductance and axonal integrity, which are crucial for normal brain functioning. Previous studies suggested that different subtypes of oligodendrocytes in the CNS form different types of myelin determined by the diameter of axons in the unit. However, the molecular mechanisms underlying the developmental association of different types of oligodendrocytes with different fiber sizes remain elusive. In the present study, we present the evidence that the intracellular Ca2+ release channel associated receptor (Itpr2) contributes to this developmental process. During early development, Itpr2 is selectively up-regulated in oligodendrocytes coinciding with the initiation of myelination. Functional analyses in both conventional and conditional Itpr2 mutant mice revealed that Itpr2 deficiency causes a developmental delay of OL differentiation, resulting in an increased percentage of CAII+ type I/II OLs which prefer to myelinate small-diameter axons in the CNS. The increased percentage of small caliber myelinated axons leads to an abnormal compound action potentials (CAP) in the optic nerves. Together, these findings revealed a previously unrecognized role for Itpr2-mediated calcium signaling in regulating the development of different types of oligodendrocytes.
Collapse
Affiliation(s)
- Ruyi Mei
- College of Life Sciences, Zhejiang University, Hangzhou, China.,Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Institute of Developmental and Regenerative Biology, Hangzhou Normal University, Hangzhou, China
| | - Linyu Huang
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Institute of Developmental and Regenerative Biology, Hangzhou Normal University, Hangzhou, China
| | - Mengyuan Wu
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Institute of Developmental and Regenerative Biology, Hangzhou Normal University, Hangzhou, China
| | - Chunxia Jiang
- College of Life Sciences, Zhejiang University, Hangzhou, China.,Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Institute of Developmental and Regenerative Biology, Hangzhou Normal University, Hangzhou, China
| | - Aifen Yang
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Institute of Developmental and Regenerative Biology, Hangzhou Normal University, Hangzhou, China
| | - Huaping Tao
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Institute of Developmental and Regenerative Biology, Hangzhou Normal University, Hangzhou, China
| | - Kang Zheng
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Institute of Developmental and Regenerative Biology, Hangzhou Normal University, Hangzhou, China
| | - Junlin Yang
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Institute of Developmental and Regenerative Biology, Hangzhou Normal University, Hangzhou, China
| | - Wanhua Shen
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Institute of Developmental and Regenerative Biology, Hangzhou Normal University, Hangzhou, China
| | - Xianjun Chen
- Department of Physiology, Research Center of Neuroscience, Chongqing Medical University, Chongqing, China
| | - Xiaofeng Zhao
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Institute of Developmental and Regenerative Biology, Hangzhou Normal University, Hangzhou, China
| | - Mengsheng Qiu
- College of Life Sciences, Zhejiang University, Hangzhou, China.,Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Institute of Developmental and Regenerative Biology, Hangzhou Normal University, Hangzhou, China
| |
Collapse
|
32
|
Degrugillier L, Prautsch KM, Schaefer DJ, Guzman R, Schären S, Kalbermatten DF, Madduri S. A new model of chronic peripheral nerve compression for basic research and pharmaceutical drug testing. Regen Med 2021; 16:931-947. [PMID: 34553612 DOI: 10.2217/rme-2020-0129] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Aim: To develop a consistent model to standardize research in the field of chronic peripheral nerve neuropathy. Methods: The left sciatic nerve of 8-week-old Sprague-Dawley rats was compressed using a customized instrument leaving a defined post injury nerve lumen (400 μm, 250 μm, 100 μm, 0 μm) for 6 weeks. Sensory and motor outcomes were measured weekly, and histomorphology and electrophysiology after 6 weeks. Results: The findings demonstrated compression depth-dependent sensory and motor pathologies. Quantitative measurements revealed a significant myelin degeneration, axon irregularities and muscle atrophy. At the functional level, we highlighted the dynamics of the different injury profiles. Conclusion: Our novel model of chronic peripheral nerve compression is a useful tool for research on pathophysiology and new therapeutic approaches.
Collapse
Affiliation(s)
- Lucas Degrugillier
- Department of Pathology, University Hospital Basel, Basel, 4021, Switzerland.,Department of Biomedical Engineering, University of Basel, Allschwil, 4123, Switzerland.,Department of Plastic, Reconstructive, Aesthetic & Hand Surgery, University Hospital Basel, University of Basel, Basel, 4021, Switzerland
| | - Katharina M Prautsch
- Department of Pathology, University Hospital Basel, Basel, 4021, Switzerland.,Department of Biomedical Engineering, University of Basel, Allschwil, 4123, Switzerland.,Department of Plastic, Reconstructive, Aesthetic & Hand Surgery, University Hospital Basel, University of Basel, Basel, 4021, Switzerland
| | - Dirk J Schaefer
- Department of Plastic, Reconstructive, Aesthetic & Hand Surgery, University Hospital Basel, University of Basel, Basel, 4021, Switzerland
| | - Raphael Guzman
- Department of Neurosurgery, University Hospital Basel, University of Basel, Basel, 4021, Switzerland
| | - Stefan Schären
- Department of Spinal Surgery, University Hospital Basel, Basel, 4021, Switzerland
| | - Daniel F Kalbermatten
- Department of Plastic, Reconstructive, Aesthetic & Hand Surgery, University Hospital Basel, University of Basel, Basel, 4021, Switzerland.,Bioengineering & Neuroregeneration, Department of Surgery, Geneva University Hospitals & University of Geneva, 1211, Geneva, Switzerland.,Plastic, Reconstructive & Aesthetic Srugery, Department of Surgery, Geneva University Hospitals & University of Geneva, 1211, Geneva, Switzerland
| | - Srinivas Madduri
- Department of Biomedical Engineering, University of Basel, Allschwil, 4123, Switzerland.,Department of Plastic, Reconstructive, Aesthetic & Hand Surgery, University Hospital Basel, University of Basel, Basel, 4021, Switzerland.,Bioengineering & Neuroregeneration, Department of Surgery, Geneva University Hospitals & University of Geneva, 1211, Geneva, Switzerland.,Plastic, Reconstructive & Aesthetic Srugery, Department of Surgery, Geneva University Hospitals & University of Geneva, 1211, Geneva, Switzerland
| |
Collapse
|
33
|
Riccio J, Alcaine A, Rocher S, Martinez-Mateu L, Laranjo S, Saiz J, Laguna P, Martínez JP. Characterization of Atrial Propagation Patterns and Fibrotic Substrate With a Modified Omnipolar Electrogram Strategy in Multi-Electrode Arrays. Front Physiol 2021; 12:674223. [PMID: 34539424 PMCID: PMC8446360 DOI: 10.3389/fphys.2021.674223] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Accepted: 07/13/2021] [Indexed: 11/15/2022] Open
Abstract
Introduction: The omnipolar electrogram method was recently proposed to try to generate orientation-independent electrograms. It estimates the electric field from the bipolar electrograms of a clique, under the assumption of locally plane and homogeneous propagation. The local electric field evolution over time describes a loop trajectory from which omnipolar signals in the propagation direction, substrate and propagation features, are derived. In this work, we propose substrate and conduction velocity mapping modalities based on a modified version of the omnipolar electrogram method, which aims to reduce orientation-dependent residual components in the standard approach. Methods: A simulated electrical propagation in 2D, with a tissue including a circular patch of diffuse fibrosis, was used for validation. Unipolar electrograms were calculated in a multi-electrode array, also deriving bipolar electrograms along the two main directions of the grid. Simulated bipolar electrograms were also contaminated with real noise, to assess the robustness of the mapping strategies against noise. The performance of the maps in identifying fibrosis and in reproducing unipolar reference voltage maps was evaluated. Bipolar voltage maps were also considered for performance comparison. Results: Results show that the modified omnipolar mapping strategies are more accurate and robust against noise than bipolar and standard omnipolar maps in fibrosis detection (accuracies higher than 85 vs. 80% and 70%, respectively). They present better correlation with unipolar reference voltage maps than bipolar and original omnipolar maps (Pearson's correlations higher than 0.75 vs. 0.60 and 0.70, respectively). Conclusion: The modified omnipolar method improves fibrosis detection, characterization of substrate and propagation, also reducing the residual sensitivity to directionality over the standard approach and improving robustness against noise. Nevertheless, studies with real electrograms will elucidate its impact in catheter ablation interventions.
Collapse
Affiliation(s)
- Jennifer Riccio
- Biomedical Signal Interpretation and Computational Simulation Group, Aragón Institute of Engineering Research, IIS Aragón, Universidad de Zaragoza, Zaragoza, Spain
| | - Alejandro Alcaine
- Biomedical Signal Interpretation and Computational Simulation Group, Aragón Institute of Engineering Research, IIS Aragón, Universidad de Zaragoza, Zaragoza, Spain.,Facultad de Ciencias de la Salud, Universidad San Jorge, Zaragoza, Spain.,Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina, Zaragoza, Spain
| | - Sara Rocher
- Centro de Investigación e Innovación en Ingeniería, Universitat Politècnica de València, Valencia, Spain
| | - Laura Martinez-Mateu
- Departamento de Teoría de la Señal y Comunicaciones y Sistemas Telemáticos y Computación, Universidad Rey Juan Carlos, Madrid, Spain
| | - Sergio Laranjo
- Department of Pediatric Cardiology, Hospital Santa Marta, Centro Hospitalar de Lisboa Central, Lisbon, Portugal
| | - Javier Saiz
- Centro de Investigación e Innovación en Ingeniería, Universitat Politècnica de València, Valencia, Spain
| | - Pablo Laguna
- Biomedical Signal Interpretation and Computational Simulation Group, Aragón Institute of Engineering Research, IIS Aragón, Universidad de Zaragoza, Zaragoza, Spain.,Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina, Zaragoza, Spain
| | - Juan Pablo Martínez
- Biomedical Signal Interpretation and Computational Simulation Group, Aragón Institute of Engineering Research, IIS Aragón, Universidad de Zaragoza, Zaragoza, Spain.,Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina, Zaragoza, Spain
| |
Collapse
|
34
|
Heida A, van Schie MS, van der Does WFB, Taverne YJHJ, Bogers AJJC, de Groot NMS. Reduction of Conduction Velocity in Patients with Atrial Fibrillation. J Clin Med 2021; 10:2614. [PMID: 34198544 DOI: 10.3390/jcm10122614] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 06/05/2021] [Accepted: 06/09/2021] [Indexed: 11/24/2022] Open
Abstract
It is unknown to what extent atrial fibrillation (AF) episodes affect intra-atrial conduction velocity (CV) and whether regional differences in local CV heterogeneities exist during sinus rhythm. This case-control study aims to compare CV assessed throughout both atria between patients with and without AF. Patients (n = 34) underwent intra-operative epicardial mapping of the right atrium (RA), Bachmann’s bundle (BB), left atrium (LA) and pulmonary vein area (PVA). CV vectors were constructed to calculate median CV in addition to total activation times (TAT) and unipolar voltages. Biatrial median CV did not differ between patients with and without AF (90 ± 8 cm/s vs. 92 ± 6 cm/s, p = 0.56); only BB showed a CV reduction in the AF group (79 ± 12 cm/s vs. 88 ± 11 cm/s, p = 0.02). In patients without AF, there was no predilection site for the lowest CV (P5) (RA: 12%; BB: 29%; LA: 29%; PVA: 29%). In patients with AF, lowest CV was most often measured at BB (53%) and ranged between 15 to 22 cm/s (median: 20 cm/s). Lowest CVs were also measured at the LA (18%) and PVA (29%), but not at the RA. AF was associated with a prolonged TAT (p = 0.03) and decreased voltages (P5) at BB (p = 0.02). BB was a predilection site for slowing of conduction in patients with AF. Prolonged TAT and decreased voltages were also found at this site. The next step will be to determine the relevance of a reduced CV at BB in relation to AF development and maintenance.
Collapse
|
35
|
Kahle AK, Gallotti RG, Alken FA, Meyer C, Moore JP. Electrophysiological Characteristics of Intra-Atrial Reentrant Tachycardia in Adult Congenital Heart Disease: Implications for Catheter Ablation. J Am Heart Assoc 2021; 10:e020835. [PMID: 34121415 PMCID: PMC8403273 DOI: 10.1161/jaha.121.020835] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Background Ultra‐high‐density mapping enables detailed mechanistic analysis of atrial reentrant tachycardia but has yet to be used to assess circuit conduction velocity (CV) patterns in adults with congenital heart disease. Methods and Results Circuit pathways and central isthmus CVs were calculated from consecutive ultra‐high‐density isochronal maps at 2 tertiary centers over a 3‐year period. Circuits using anatomic versus surgical obstacles were considered separately and pathway length <50th percentile identified small circuits. CV analysis was used to derive a novel index for prediction of postablation conduction block. A total of 136 supraventricular tachycardias were studied (60% intra‐atrial reentrant, 14% multiple loop). Circuits with anatomic versus surgical obstacles featured longer pathway length (119 mm; interquartile range [IQR], 80–150 versus 78 mm; IQR, 63–95; P<0.001), faster central isthmus CV (0.1 m/s; IQR, 0.06–0.25 versus 0.07 m/s; IQR, 0.05–0.10; P=0.016), faster non‐isthmus CV (0.52 m/s; IQR, 0.33–0.71 versus 0.38 m/s; IQR, 0.27–0.46; P=0.009), and fewer slow isochrones (4; IQR, 2.3–6.8 versus 6; IQR 5–7; P=0.008). Both central isthmus (R2=0.45; P<0.001) and non‐isthmus CV (R2=0.71; P<0.001) correlated with pathway length, whereas central isthmus CV <0.15 m/s was ubiquitous for small circuits. Non‐isthmus CV in tachycardia correlated with CV during block validation (R2=0.94; P<0.001) and a validation map to tachycardia conduction time ratio >85% predicted isthmus block in all cases. Over >1 year of follow‐up, arrhythmia‐free survival was better for homogeneous CV patterns (90% versus 57%; P=0.04). Conclusions Ultra‐high‐density mapping‐guided CV analysis distinguishes atrial reentrant patterns in adults with congenital heart disease with surgical obstacles producing slower and smaller circuits. Very slow central isthmus CV may be essential for atrial tachycardia maintenance in small circuits, and non‐isthmus conduction time in tachycardia appears to be useful for rapid assessment of postablation conduction block.
Collapse
Affiliation(s)
- Ann-Kathrin Kahle
- Division of Cardiology Evangelishces Krankenhaus Düsseldorf Düsseldorf Germany.,Institute of Neural and Sensory Physiology Heinrich Heine University DüsseldorfMedical Faculty Düsseldorf Germany.,cardiac Neuro- and Electrophysiology Research Consortium Düsseldorf Germany.,German Centre for Cardiovascular Research Partner Site Hamburg/Kiel/Lübeck Germany.,Clinic for Cardiology University Heart & Vascular CenterUniversity Hospital Hamburg-Eppendorf Hamburg Germany
| | - Roberto G Gallotti
- Division of Cardiology Department of Medicine University of California at Los Angeles Medical Center, Ahmanson/Adult Congenital Heart Disease Center Los Angeles CA
| | - Fares-Alexander Alken
- Division of Cardiology Evangelishces Krankenhaus Düsseldorf Düsseldorf Germany.,Institute of Neural and Sensory Physiology Heinrich Heine University DüsseldorfMedical Faculty Düsseldorf Germany.,cardiac Neuro- and Electrophysiology Research Consortium Düsseldorf Germany.,German Centre for Cardiovascular Research Partner Site Hamburg/Kiel/Lübeck Germany.,Clinic for Cardiology University Heart & Vascular CenterUniversity Hospital Hamburg-Eppendorf Hamburg Germany
| | - Christian Meyer
- Division of Cardiology Evangelishces Krankenhaus Düsseldorf Düsseldorf Germany.,Institute of Neural and Sensory Physiology Heinrich Heine University DüsseldorfMedical Faculty Düsseldorf Germany.,cardiac Neuro- and Electrophysiology Research Consortium Düsseldorf Germany.,German Centre for Cardiovascular Research Partner Site Hamburg/Kiel/Lübeck Germany.,Clinic for Cardiology University Heart & Vascular CenterUniversity Hospital Hamburg-Eppendorf Hamburg Germany
| | - Jeremy P Moore
- Division of Cardiology Department of Medicine University of California at Los Angeles Medical Center, Ahmanson/Adult Congenital Heart Disease Center Los Angeles CA.,University of California at Los Angeles Cardiac Arrhythmia CenterUCLA Health SystemDavid Geffen School of Medicine at Los Angeles CA
| |
Collapse
|
36
|
Nothstein M, Luik A, Jadidi A, Sánchez J, Unger LA, Wülfers EM, Dössel O, Seemann G, Schmitt C, Loewe A. CVAR-Seg: An Automated Signal Segmentation Pipeline for Conduction Velocity and Amplitude Restitution. Front Physiol 2021; 12:673047. [PMID: 34108887 PMCID: PMC8181407 DOI: 10.3389/fphys.2021.673047] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 04/30/2021] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Rate-varying S1S2 stimulation protocols can be used for restitution studies to characterize atrial substrate, ionic remodeling, and atrial fibrillation risk. Clinical restitution studies with numerous patients create large amounts of these data. Thus, an automated pipeline to evaluate clinically acquired S1S2 stimulation protocol data necessitates consistent, robust, reproducible, and precise evaluation of local activation times, electrogram amplitude, and conduction velocity. Here, we present the CVAR-Seg pipeline, developed focusing on three challenges: (i) No previous knowledge of the stimulation parameters is available, thus, arbitrary protocols are supported. (ii) The pipeline remains robust under different noise conditions. (iii) The pipeline supports segmentation of atrial activities in close temporal proximity to the stimulation artifact, which is challenging due to larger amplitude and slope of the stimulus compared to the atrial activity. METHODS AND RESULTS The S1 basic cycle length was estimated by time interval detection. Stimulation time windows were segmented by detecting synchronous peaks in different channels surpassing an amplitude threshold and identifying time intervals between detected stimuli. Elimination of the stimulation artifact by a matched filter allowed detection of local activation times in temporal proximity. A non-linear signal energy operator was used to segment periods of atrial activity. Geodesic and Euclidean inter electrode distances allowed approximation of conduction velocity. The automatic segmentation performance of the CVAR-Seg pipeline was evaluated on 37 synthetic datasets with decreasing signal-to-noise ratios. Noise was modeled by reconstructing the frequency spectrum of clinical noise. The pipeline retained a median local activation time error below a single sample (1 ms) for signal-to-noise ratios as low as 0 dB representing a high clinical noise level. As a proof of concept, the pipeline was tested on a CARTO case of a paroxysmal atrial fibrillation patient and yielded plausible restitution curves for conduction speed and amplitude. CONCLUSION The proposed openly available CVAR-Seg pipeline promises fast, fully automated, robust, and accurate evaluations of atrial signals even with low signal-to-noise ratios. This is achieved by solving the proximity problem of stimulation and atrial activity to enable standardized evaluation without introducing human bias for large data sets.
Collapse
Affiliation(s)
- Mark Nothstein
- Institute of Biomedical Engineering (IBT), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Armin Luik
- Medizinische Klinik IV, Städtisches Klinikum Karlsruhe, Karlsruhe, Germany
| | - Amir Jadidi
- Klinik für Kardiologie und Angiologie II, University Heart Center Freiburg-Bad Krozingen, Bad Krozingen, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Jorge Sánchez
- Institute of Biomedical Engineering (IBT), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Laura A. Unger
- Institute of Biomedical Engineering (IBT), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Eike M. Wülfers
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg-Bad Krozingen, Freiburg, Germany
| | - Olaf Dössel
- Institute of Biomedical Engineering (IBT), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Gunnar Seemann
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg-Bad Krozingen, Freiburg, Germany
| | - Claus Schmitt
- Medizinische Klinik IV, Städtisches Klinikum Karlsruhe, Karlsruhe, Germany
| | - Axel Loewe
- Institute of Biomedical Engineering (IBT), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| |
Collapse
|
37
|
Woodworth LA, Cansız B, Kaliske M. A numerical study on the effects of spatial and temporal discretization in cardiac electrophysiology. Int J Numer Method Biomed Eng 2021; 37:e3443. [PMID: 33522111 DOI: 10.1002/cnm.3443] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 12/16/2020] [Accepted: 01/23/2021] [Indexed: 06/12/2023]
Abstract
Millions of degrees of freedom are often required to accurately represent the electrophysiology of the myocardium due to the presence of discretization effects. This study seeks to explore the influence of temporal and spatial discretization on the simulation of cardiac electrophysiology in conjunction with changes in modeling choices. Several finite element analyses are performed to examine how discretization affects solution time, conduction velocity and electrical excitation. Discretization effects are considered along with changes in the electrophysiology model and solution approach. Two action potential models are considered: the Aliev-Panfilov model and the ten Tusscher-Noble-Noble-Panfilov model. The solution approaches consist of two time integration schemes and different treatments for solving the local system of ordinary differential equations. The efficiency and stability of the calculation approaches are demonstrated to be dependent on the action potential model. The dependency of the conduction velocity on the element size and time step is shown to be different for changes in material parameters. Finally, the discrepancies between the wave propagation in coarse and fine meshes are analyzed based on the temporal evolution of the transmembrane potential at a node and its neighboring Gauss points. Insight obtained from this study can be used to suggest new methods to improve the efficiency of simulations in cardiac electrophysiology.
Collapse
Affiliation(s)
- Lucas A Woodworth
- Institute for Structural Analysis, Technische Universität Dresden, Dresden, Germany
| | - Barış Cansız
- Institute for Structural Analysis, Technische Universität Dresden, Dresden, Germany
| | - Michael Kaliske
- Institute for Structural Analysis, Technische Universität Dresden, Dresden, Germany
| |
Collapse
|
38
|
Gaeta S, Bahnson TD, Henriquez C. High-Resolution Measurement of Local Activation Time Differences From Bipolar Electrogram Amplitude. Front Physiol 2021; 12:653645. [PMID: 33967825 PMCID: PMC8100452 DOI: 10.3389/fphys.2021.653645] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 03/30/2021] [Indexed: 11/13/2022] Open
Abstract
Localized changes in myocardial conduction velocity (CV) are pro-arrhythmic, but high-resolution mapping of local CV is not yet possible during clinical electrophysiology procedures. This is in part because measurement of local CV at small spatial scales (1 mm) requires accurate annotation of local activation time (LAT) differences with very high temporal resolution (≤1 ms), beyond that of standard clinical methods. We sought to develop a method for high-resolution measurement of LAT differences and validate against existing techniques. First, we use a simplified theoretical model to identify a quantitative relationship between the LAT difference of a pair of electrodes and the peak amplitude of the bipolar EGM measured between them. This allows LAT differences to be calculated from bipolar EGM peak amplitude, by a novel "Determination of EGM Latencies by Transformation of Amplitude" (DELTA) method. Next, we use simulated EGMs from a computational model to validate this method. With 1 kHz sampling, LAT differences less than 4 ms were more accurately measured with DELTA than by standard LAT annotation (mean error 3.8% vs. 22.9%). In a 1-dimensional and a 2-dimension model, CV calculations were more accurate using LAT differences found by the DELTA method than by standard LAT annotation (by unipolar dV/dt timing). DELTA-derived LAT differences were more accurate than standard LAT annotation in simulated complex fractionated EGMs from a model incorporating fibrosis. Finally, we validated the DELTA method in vivo using 18,740 bipolar EGMs recorded from the left atrium of 10 atrial fibrillation patients undergoing catheter ablation. Using clinical EGMs, there was agreement in LAT differences found by DELTA, standard LAT annotation, and unipolar waveform cross-correlation. These results demonstrate an underlying relationship between a bipolar EGM's peak amplitude and the activation time difference between its two electrodes. Our computational modeling and clinical results suggest this relationship can be leveraged clinically to improve measurement accuracy for small LAT differences, which may improve CV measurement at small spatial scales.
Collapse
Affiliation(s)
- Stephen Gaeta
- Inova Heart and Vascular Institute, Falls Church, VA, United States.,Division of Cardiology, Duke University Medical Center, Durham, NC, United States
| | - Tristram D Bahnson
- Division of Cardiology, Duke University Medical Center, Durham, NC, United States
| | - Craig Henriquez
- Department of Biomedical Engineering, Duke University, Durham, NC, United States
| |
Collapse
|
39
|
Liu SH, Lin YJ, Lee PT, Vicera JJ, Chang SL, Lo LW, Hu YF, Chung FP, Tuan TC, Chao TF, Liao JN, Chang TY, Lin CY, Wu CI, Liu CM, Cheng WH, Chen SA. The isthmus characteristics of scar-related macroreentrant atrial tachycardia in patients with and without cardiac surgery. J Cardiovasc Electrophysiol 2021; 32:1921-1930. [PMID: 33834555 DOI: 10.1111/jce.15034] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Revised: 03/09/2021] [Accepted: 03/16/2021] [Indexed: 11/28/2022]
Abstract
INTRODUCTION Identifying the critical isthmus (CI) in scar-related macroreentrant atrial tachycardia (AT) is challenging, especially for patients with cardiac surgery. We aimed to investigate the electrophysiological characteristics of scar-related macroreentrant ATs in patients with and without cardiac surgery. METHODS A prospective study of 31 patients (mean age 59.4 ± 9.81 years old) with scar-related macroreentrant ATs were enrolled for investigation of substrate properties. Patients were categorized into the nonsurgery (n = 18) and surgery group (n = 13). The CIs were defined by concealed entrainment, conduction velocity less than 0.3 m/s, and the presence of local fractionated electrograms. RESULTS Among the 31 patients, a total of 65 reentrant circuits and 76 CIs were identified on the coherent map. The scar in the surgical group is larger than the nonsurgical group (18.81 ± 9.22 vs. 10.23 ± 5.34%, p = .016). The CIs in surgical group have longer CI length (15.27 ± 4.89 vs. 11.20 ± 2.96 mm, p = .004), slower conduction velocity (0.46 ± 0.19 vs. 0.69 ± 0.14 m/s, p < .001), and longer total activation time (45.34 ± 9.04 vs. 38.24 ± 8.41%, p = .016) than those in the nonsurgical group. After ablation, 93.54% of patients remained in sinus rhythm during a follow-up of 182 ± 19 days. CONCLUSION The characteristics of the isthmus in macroreentrant AT are diverse, especially for surgical scar-related AT. The identification of CIs can facilitate the successful ablation of scar-related ATs.
Collapse
Affiliation(s)
- Shin-Huei Liu
- Division of Cardiology, Department of Medicine, Heart Rhythm Center, Taipei Veterans General Hospital, Taipei, Taiwan.,Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Yenn-Jiang Lin
- Division of Cardiology, Department of Medicine, Heart Rhythm Center, Taipei Veterans General Hospital, Taipei, Taiwan.,Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Po-Tseng Lee
- Division of Cardiology, Department of Medicine, Heart Rhythm Center, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Jennifer Jeanne Vicera
- Division of Cardiology, Department of Medicine, Heart Rhythm Center, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Shih-Lin Chang
- Division of Cardiology, Department of Medicine, Heart Rhythm Center, Taipei Veterans General Hospital, Taipei, Taiwan.,Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Li-Wei Lo
- Division of Cardiology, Department of Medicine, Heart Rhythm Center, Taipei Veterans General Hospital, Taipei, Taiwan.,Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Yu-Feng Hu
- Division of Cardiology, Department of Medicine, Heart Rhythm Center, Taipei Veterans General Hospital, Taipei, Taiwan.,Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Fa-Po Chung
- Division of Cardiology, Department of Medicine, Heart Rhythm Center, Taipei Veterans General Hospital, Taipei, Taiwan.,Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Ta-Chuan Tuan
- Division of Cardiology, Department of Medicine, Heart Rhythm Center, Taipei Veterans General Hospital, Taipei, Taiwan.,Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Tze-Fan Chao
- Division of Cardiology, Department of Medicine, Heart Rhythm Center, Taipei Veterans General Hospital, Taipei, Taiwan.,Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Jo-Nan Liao
- Division of Cardiology, Department of Medicine, Heart Rhythm Center, Taipei Veterans General Hospital, Taipei, Taiwan.,Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Ting-Yung Chang
- Division of Cardiology, Department of Medicine, Heart Rhythm Center, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Chin-Yu Lin
- Division of Cardiology, Department of Medicine, Heart Rhythm Center, Taipei Veterans General Hospital, Taipei, Taiwan.,Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Cheng-I Wu
- Division of Cardiology, Department of Medicine, Heart Rhythm Center, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Chih-Min Liu
- Division of Cardiology, Department of Medicine, Heart Rhythm Center, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Wen-Han Cheng
- Division of Cardiology, Department of Medicine, Heart Rhythm Center, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Shih-Ann Chen
- Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan.,Cardiovascular Center, Taichung Veterans General Hospital, Taichung, Taiwan
| |
Collapse
|
40
|
He Y, Wang G, Gao H, Liu Y, Li H, Feng Y, Tang J. Prolonged duration of repolarization and decreased conduction velocity in the atrial myocardium after hypothermic ischemia-reperfusion may be related to expressions of inward rectifier potassium channel 2.1 protein and connexin 40. Perfusion 2021; 36:146-153. [PMID: 32650696 DOI: 10.1177/0267659120934612] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVES The study aimed to determine the role of inward rectifier potassium channel 2.1 protein and connexin 40 expressions in regulating the duration of repolarization and conduction velocity of right atrial myocardium in rats following hypothermic ischemia-reperfusion. METHODS The Langendorff isolated rat cardiac perfusion models were divided into control (C) and hypothermic ischemia-reperfusion groups, with 8 models in group C and 16 models in group ischemia-reperfusion. Depending on the incidence of atrial arrhythmia after reperfusion, the models in group ischemia-reperfusion were further divided into reperfusion non-atrial arrhythmia or reperfusion atrial arrhythmia subgroup. Right atrial monophasic action potential duration at 50% and 90% of repolarization after 30 minutes of continuous perfusion in group C and group ischemia-reperfusion (T0), 105 minutes of continuous perfusion in group C or after 15 minutes of reperfusion in group ischemia-reperfusion (T1) and 120 minutes of continuous perfusion in group C or 30 minutes of reperfusion in group ischemia-reperfusion (T2) were recorded. Right atrial conduction velocity and effective refractory period were recorded at T2. Then, the expressions of inward rectifier potassium channel 2.1 protein and connexin 40 in the right atrial myocardium were detected. RESULTS Monophasic action potential duration at 50% and 90% were higher at T1 and T2 than those at T0 in subgroup reperfusion atrial arrhythmia (p < 0.05); monophasic action potential duration at 50% in subgroup reperfusion atrial arrhythmia were larger than group C and subgroup reperfusion non-atrial arrhythmia at T1 and T2 (p < 0.05); monophasic action potential duration at 90% in subgroup reperfusion atrial arrhythmia were larger than group C and subgroup reperfusion non-atrial arrhythmia at T1 and T2 (p < 0.05); effective refractory period in subgroup reperfusion atrial arrhythmia was greater than that in group C and subgroup reperfusion non-atrial arrhythmia, and the conduction velocity and the expressions of inward rectifier potassium channel 2.1 protein and connexin 40 were significantly lower than group C and subgroup reperfusion non-atrial arrhythmia (p < 0.05). CONCLUSIONS The prolonged duration of repolarization and a decrease in conduction velocity of the atrial myocardium occur in rats after hypothermic ischemia-reperfusion. These observed effects may be related to the downregulated expressions of connexin 40 and inward rectifier potassium channel 2.1.
Collapse
Affiliation(s)
- Youqin He
- School of Anesthesiology, Guizhou Medical University, Guiyang, P.R. China
| | - Guilong Wang
- Department of Anesthesiology, The People's Hospital of Zhijin County, Bijie, P.R. China
| | - Hong Gao
- The Third Affiliated Hospital of Guizhou Medical University, Duyun, P.R. China
| | - Yanqiu Liu
- Department of Anesthesiology, The Affiliated Hospital of Guizhou Medical University, Guiyang, P.R. China
| | - Huayu Li
- School of Anesthesiology, Guizhou Medical University, Guiyang, P.R. China
| | - Yurong Feng
- School of Anesthesiology, Guizhou Medical University, Guiyang, P.R. China
| | - Jian Tang
- School of Anesthesiology, Guizhou Medical University, Guiyang, P.R. China
| |
Collapse
|
41
|
Williams SE, Roney CH, Connolly A, Sim I, Whitaker J, O’Hare D, Kotadia I, O’Neill L, Corrado C, Bishop M, Niederer SA, Wright M, O’Neill M, Linton NWF. OpenEP: A Cross-Platform Electroanatomic Mapping Data Format and Analysis Platform for Electrophysiology Research. Front Physiol 2021; 12:646023. [PMID: 33716795 PMCID: PMC7952326 DOI: 10.3389/fphys.2021.646023] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Accepted: 01/29/2021] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Electroanatomic mapping systems are used to support electrophysiology research. Data exported from these systems is stored in proprietary formats which are challenging to access and storage-space inefficient. No previous work has made available an open-source platform for parsing and interrogating this data in a standardized format. We therefore sought to develop a standardized, open-source data structure and associated computer code to store electroanatomic mapping data in a space-efficient and easily accessible manner. METHODS A data structure was defined capturing the available anatomic and electrical data. OpenEP, implemented in MATLAB, was developed to parse and interrogate this data. Functions are provided for analysis of chamber geometry, activation mapping, conduction velocity mapping, voltage mapping, ablation sites, and electrograms as well as visualization and input/output functions. Performance benchmarking for data import and storage was performed. Data import and analysis validation was performed for chamber geometry, activation mapping, voltage mapping and ablation representation. Finally, systematic analysis of electrophysiology literature was performed to determine the suitability of OpenEP for contemporary electrophysiology research. RESULTS The average time to parse clinical datasets was 400 ± 162 s per patient. OpenEP data was two orders of magnitude smaller than compressed clinical data (OpenEP: 20.5 ± 8.7 Mb, vs clinical: 1.46 ± 0.77 Gb). OpenEP-derived geometry metrics were correlated with the same clinical metrics (Area: R 2 = 0.7726, P < 0.0001; Volume: R 2 = 0.5179, P < 0.0001). Investigating the cause of systematic bias in these correlations revealed OpenEP to outperform the clinical platform in recovering accurate values. Both activation and voltage mapping data created with OpenEP were correlated with clinical values (mean voltage R 2 = 0.8708, P < 0.001; local activation time R 2 = 0.8892, P < 0.0001). OpenEP provides the processing necessary for 87 of 92 qualitatively assessed analysis techniques (95%) and 119 of 136 quantitatively assessed analysis techniques (88%) in a contemporary cohort of mapping studies. CONCLUSIONS We present the OpenEP framework for evaluating electroanatomic mapping data. OpenEP provides the core functionality necessary to conduct electroanatomic mapping research. We demonstrate that OpenEP is both space-efficient and accurately representative of the original data. We show that OpenEP captures the majority of data required for contemporary electroanatomic mapping-based electrophysiology research and propose a roadmap for future development.
Collapse
Affiliation(s)
- Steven E. Williams
- King’s College London, London, United Kingdom
- Centre for Cardiovascular Science, The University of Edinburgh, Edinburgh, United Kingdom
| | | | - Adam Connolly
- King’s College London, London, United Kingdom
- Invicro, Ltd., London, United Kingdom
| | - Iain Sim
- King’s College London, London, United Kingdom
| | | | | | | | | | | | | | | | - Matt Wright
- King’s College London, London, United Kingdom
- Guy’s and St Thomas’ NHS Foundation Trust, London, United Kingdom
| | - Mark O’Neill
- King’s College London, London, United Kingdom
- Guy’s and St Thomas’ NHS Foundation Trust, London, United Kingdom
| | | |
Collapse
|
42
|
Jæger KH, Charwat V, Wall S, Healy KE, Tveito A. Identifying Drug Response by Combining Measurements of the Membrane Potential, the Cytosolic Calcium Concentration, and the Extracellular Potential in Microphysiological Systems. Front Pharmacol 2021; 11:569489. [PMID: 33628168 PMCID: PMC7898238 DOI: 10.3389/fphar.2020.569489] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 11/16/2020] [Indexed: 01/01/2023] Open
Abstract
Cardiomyocytes derived from human induced pluripotent stem cells (hiPSC-CMs) offer a new means to study and understand the human cardiac action potential, and can give key insight into how compounds may interact with important molecular pathways to destabilize the electrical function of the heart. Important features of the action potential can be readily measured using standard experimental techniques, such as the use of voltage sensitive dyes and fluorescent genetic reporters to estimate transmembrane potentials and cytosolic calcium concentrations. Using previously introduced computational procedures, such measurements can be used to estimate the current density of major ion channels present in hiPSC-CMs, and how compounds may alter their behavior. However, due to the limitations of optical recordings, resolving the sodium current remains difficult from these data. Here we show that if these optical measurements are complemented with observations of the extracellular potential using multi electrode arrays (MEAs), we can accurately estimate the current density of the sodium channels. This inversion of the sodium current relies on observation of the conduction velocity which turns out to be straightforwardly computed using measurements of extracellular waves across the electrodes. The combined data including the membrane potential, the cytosolic calcium concentration and the extracellular potential further opens up for the possibility of accurately estimating the effect of novel drugs applied to hiPSC-CMs.
Collapse
Affiliation(s)
| | - Verena Charwat
- Department of Bioengineering, University of California, Berkeley, CA, United States
| | | | - Kevin E. Healy
- Department of Bioengineering, University of California, Berkeley, CA, United States
- Department of Material Science and Engineering, University of California, Berkeley, CA, United States
| | - Aslak Tveito
- Simula Research Laboratory, Oslo, Norway
- Department of Informatics, University of Oslo, Oslo, Norway
| |
Collapse
|
43
|
Cullen CL, Pepper RE, Clutterbuck MT, Pitman KA, Oorschot V, Auderset L, Tang AD, Ramm G, Emery B, Rodger J, Jolivet RB, Young KM. Periaxonal and nodal plasticities modulate action potential conduction in the adult mouse brain. Cell Rep 2021; 34:108641. [PMID: 33472075 DOI: 10.1016/j.celrep.2020.108641] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 11/18/2020] [Accepted: 12/21/2020] [Indexed: 12/25/2022] Open
Abstract
Central nervous system myelination increases action potential conduction velocity. However, it is unclear how myelination is coordinated to ensure the temporally precise arrival of action potentials and facilitate information processing within cortical and associative circuits. Here, we show that myelin sheaths, supported by mature oligodendrocytes, remain plastic in the adult mouse brain and undergo subtle structural modifications to influence action potential conduction velocity. Repetitive transcranial magnetic stimulation and spatial learning, two stimuli that modify neuronal activity, alter the length of the nodes of Ranvier and the size of the periaxonal space within active brain regions. This change in the axon-glial configuration is independent of oligodendrogenesis and robustly alters action potential conduction velocity. Because aptitude in the spatial learning task was found to correlate with action potential conduction velocity in the fimbria-fornix pathway, modifying the axon-glial configuration may be a mechanism that facilitates learning in the adult mouse brain.
Collapse
Affiliation(s)
- Carlie L Cullen
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS 7000, Australia
| | - Renee E Pepper
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS 7000, Australia
| | | | - Kimberley A Pitman
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS 7000, Australia
| | - Viola Oorschot
- Ramaciotti Centre for Cryo-Electron Microscopy, Monash University, Melbourne, VIC 3800, Australia
| | - Loic Auderset
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS 7000, Australia
| | - Alexander D Tang
- Experimental and Regenerative Neuroscience, School of Biological Sciences, University of Western Australia, Perth, WA 6009, Australia
| | - Georg Ramm
- Ramaciotti Centre for Cryo-Electron Microscopy, Monash University, Melbourne, VIC 3800, Australia
| | - Ben Emery
- Jungers Center for Neurosciences Research, Department of Neurology, Oregon Health and Science University, Portland, OR 97239-3098, USA
| | - Jennifer Rodger
- Experimental and Regenerative Neuroscience, School of Biological Sciences, University of Western Australia, Perth, WA 6009, Australia; Perron Institute for Neurological and Translational Research, Perth, WA 6009, Australia
| | - Renaud B Jolivet
- Département de Physique Nucléaire et Corpusculaire, University of Geneva, 1211 Geneva 4, Switzerland
| | - Kaylene M Young
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS 7000, Australia.
| |
Collapse
|
44
|
Andersson M, Kjer HM, Rafael-Patino J, Pacureanu A, Pakkenberg B, Thiran JP, Ptito M, Bech M, Bjorholm Dahl A, Andersen Dahl V, Dyrby TB. Axon morphology is modulated by the local environment and impacts the noninvasive investigation of its structure-function relationship. Proc Natl Acad Sci U S A 2020; 117:33649-33659. [PMID: 33376224 PMCID: PMC7777205 DOI: 10.1073/pnas.2012533117] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Axonal conduction velocity, which ensures efficient function of the brain network, is related to axon diameter. Noninvasive, in vivo axon diameter estimates can be made with diffusion magnetic resonance imaging, but the technique requires three-dimensional (3D) validation. Here, high-resolution, 3D synchrotron X-ray nano-holotomography images of white matter samples from the corpus callosum of a monkey brain reveal that blood vessels, cells, and vacuoles affect axonal diameter and trajectory. Within single axons, we find that the variation in diameter and conduction velocity correlates with the mean diameter, contesting the value of precise diameter determination in larger axons. These complex 3D axon morphologies drive previously reported 2D trends in axon diameter and g-ratio. Furthermore, we find that these morphologies bias the estimates of axon diameter with diffusion magnetic resonance imaging and, ultimately, impact the investigation and formulation of the axon structure-function relationship.
Collapse
Affiliation(s)
- Mariam Andersson
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, 2650 Hvidovre, Denmark;
- Department of Applied Mathematics and Computer Science, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - Hans Martin Kjer
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, 2650 Hvidovre, Denmark
- Department of Applied Mathematics and Computer Science, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - Jonathan Rafael-Patino
- Signal Processing Laboratory (LTS5), École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | | | - Bente Pakkenberg
- Research Laboratory for Stereology and Neuroscience, Copenhagen University Hospital, Bispebjerg, 2400 Copenhagen, Denmark
| | - Jean-Philippe Thiran
- Signal Processing Laboratory (LTS5), École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
- Radiology Department, Centre Hospitalier Universitaire Vaudois and University of Lausanne, 1011 Lausanne, Switzerland
- Center for Biomedical Imaging, 1015 Lausanne, Switzerland
| | - Maurice Ptito
- School of Optometry, University of Montreal, Montreal, QC H3T 1P1, Canada
- Department of Neuroscience, Faculty of Health Science, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Martin Bech
- Division of Medical Radiation Physics, Department of Clinical Sciences, Lund University, 221 85 Lund, Sweden
| | - Anders Bjorholm Dahl
- Department of Applied Mathematics and Computer Science, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - Vedrana Andersen Dahl
- Department of Applied Mathematics and Computer Science, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - Tim B Dyrby
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, 2650 Hvidovre, Denmark;
- Department of Applied Mathematics and Computer Science, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| |
Collapse
|
45
|
Jager F, Geršak K, Vouk P, Pirnar Ž, Trojner-Bregar A, Lučovnik M, Borovac A. Assessing Velocity and Directionality of Uterine Electrical Activity for Preterm Birth Prediction Using EHG Surface Records. Sensors (Basel) 2020; 20:E7328. [PMID: 33419319 DOI: 10.3390/s20247328] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 12/14/2020] [Accepted: 12/16/2020] [Indexed: 11/16/2022]
Abstract
The aim of the present study was to assess the capability of conduction velocity amplitudes and directions of propagation of electrohysterogram (EHG) waves to better distinguish between preterm and term EHG surface records. Using short-time cross-correlation between pairs of bipolar EHG signals (upper and lower, left and right), the conduction velocities and their directions were estimated using preterm and term EHG records of the publicly available Term–Preterm EHG DataSet with Tocogram (TPEHGT DS) and for different frequency bands below and above 1.0 Hz, where contractions and the influence of the maternal heart rate on the uterus, respectively, are expected. No significant or preferred continuous direction of propagation was found in any of the non-contraction (dummy) or contraction intervals; however, on average, a significantly lower percentage of velocity vectors was found in the vertical direction, and significantly higher in the horizontal direction, for preterm dummy intervals above 1.0 Hz. The newly defined features—the percentages of velocities in the vertical and horizontal directions, in combination with the sample entropy of the EHG signal recorded in the vertical direction, obtained from dummy intervals above 1.0 Hz—showed the highest classification accuracy of 86.8% (AUC=90.3%) in distinguishing between preterm and term EHG records of the TPEHGT DS.
Collapse
|
46
|
Niazi IK, Kamavuako EN, Holt K, Janjua TAM, Kumari N, Amjad I, Haavik H. The Effect of Spinal Manipulation on the Electrophysiological and Metabolic Properties of the Tibialis Anterior Muscle. Healthcare (Basel) 2020; 8:healthcare8040548. [PMID: 33321904 PMCID: PMC7764559 DOI: 10.3390/healthcare8040548] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 12/07/2020] [Accepted: 12/07/2020] [Indexed: 12/31/2022] Open
Abstract
There is growing evidence showing that spinal manipulation increases muscle strength in healthy individuals as well as in people with some musculoskeletal and neurological disorders. However, the underlying mechanism by which spinal manipulation changes muscle strength is less clear. This study aimed to assess the effects of a single spinal manipulation session on the electrophysiological and metabolic properties of the tibialis anterior (TA) muscle. Maximum voluntary contractions (MVC) of the ankle dorsiflexors, high-density electromyography (HDsEMG), intramuscular EMG, and near-infrared spectroscopy (NIRS) were recorded from the TA muscle in 25 participants with low level recurring spinal dysfunction using a randomized controlled crossover design. The following outcomes: motor unit discharge rate (MUDR), strength (force at MVC), muscle conduction velocity (CV), relative changes in oxy- and deoxyhemoglobin were assessed pre and post a spinal manipulation intervention and passive movement control. Repeated measures ANOVA was used to assess within and between-group differences. Following the spinal manipulation intervention, there was a significant increase in MVC (p = 0.02; avg 18.87 ± 28.35%) and a significant increase in CV in both the isometric steady-state (10% of MVC) contractions (p < 0.01; avg 22.11 ± 11.69%) and during the isometric ramp (10% of MVC) contractions (p < 0.01; avg 4.52 ± 4.58%) compared to the control intervention. There were no other significant findings. The observed TA strength and CV increase, without changes in MUDR, suggests that the strength changes observed following spinal manipulation are, in part, due to increased recruitment of larger, higher threshold motor units. Further research needs to investigate the longer term and potential functional effects of spinal manipulation in various patients who may benefit from improved muscle function and greater motor unit recruitment.
Collapse
Affiliation(s)
- Imran Khan Niazi
- Centre for Chiropractic Research, New Zealand College of Chiropractic, Auckland 1060, New Zealand; (K.H.); (N.K.); (I.A.)
- Faculty of Health & Environmental Sciences, Health & Rehabilitation Research Institute, AUT University, Auckland 0627, New Zealand
- Department of Health Science and Technology, Aalborg University, Aalborg 9220, Denmark;
- Correspondence: (I.K.N.); (H.H.)
| | - Ernest Nlandu Kamavuako
- Department of Informatics, King’s College London, London WC2R 2LS, UK;
- Faculté de Médecine, Université de Kindu, Kindu, Congo
| | - Kelly Holt
- Centre for Chiropractic Research, New Zealand College of Chiropractic, Auckland 1060, New Zealand; (K.H.); (N.K.); (I.A.)
| | | | - Nitika Kumari
- Centre for Chiropractic Research, New Zealand College of Chiropractic, Auckland 1060, New Zealand; (K.H.); (N.K.); (I.A.)
- Faculty of Health & Environmental Sciences, Health & Rehabilitation Research Institute, AUT University, Auckland 0627, New Zealand
| | - Imran Amjad
- Centre for Chiropractic Research, New Zealand College of Chiropractic, Auckland 1060, New Zealand; (K.H.); (N.K.); (I.A.)
- Faculty of Rehabilitation and Allied Sciences, Riphah International University, Islamabad 46000, Pakistan
| | - Heidi Haavik
- Centre for Chiropractic Research, New Zealand College of Chiropractic, Auckland 1060, New Zealand; (K.H.); (N.K.); (I.A.)
- Correspondence: (I.K.N.); (H.H.)
| |
Collapse
|
47
|
Abstract
Anisotropy is the property of directional dependence. In cardiac tissue, conduction velocity is anisotropic and its orientation is determined by myocyte direction. Cell shape and size, excitability, myocardial fibrosis, gap junction distribution and function are all considered to contribute to anisotropic conduction. In disease states, anisotropic conduction may be enhanced, and is implicated, in the genesis of pathological arrhythmias. The principal mechanism responsible for enhanced anisotropy in disease remains uncertain. Possible contributors include changes in cellular excitability, changes in gap junction distribution or function and cellular uncoupling through interstitial fibrosis. It has recently been demonstrated that myocyte orientation may be identified using diffusion tensor magnetic resonance imaging in explanted hearts, and multisite pacing protocols have been proposed to estimate myocyte orientation and anisotropic conduction in vivo. These tools have the potential to contribute to the understanding of the role of myocyte disarray and anisotropic conduction in arrhythmic states.
Collapse
Affiliation(s)
- Irum Kotadia
- School of Biomedical Engineering and Imaging Sciences, King’s College, London, UK
- Guy’s and St Thomas’ NHS Foundation Trust, London, UK
| | - John Whitaker
- School of Biomedical Engineering and Imaging Sciences, King’s College, London, UK
- Guy’s and St Thomas’ NHS Foundation Trust, London, UK
| | - Caroline Roney
- School of Biomedical Engineering and Imaging Sciences, King’s College, London, UK
| | - Steven Niederer
- School of Biomedical Engineering and Imaging Sciences, King’s College, London, UK
| | - Mark O’Neill
- School of Biomedical Engineering and Imaging Sciences, King’s College, London, UK
- Guy’s and St Thomas’ NHS Foundation Trust, London, UK
| | - Martin Bishop
- School of Biomedical Engineering and Imaging Sciences, King’s College, London, UK
| | - Matthew Wright
- School of Biomedical Engineering and Imaging Sciences, King’s College, London, UK
- Guy’s and St Thomas’ NHS Foundation Trust, London, UK
| |
Collapse
|
48
|
Roberts TPL, Bloy L, Ku M, Blaskey L, Jackel CR, Edgar JC, Berman JI. A Multimodal Study of the Contributions of Conduction Velocity to the Auditory Evoked Neuromagnetic Response: Anomalies in Autism Spectrum Disorder. Autism Res 2020; 13:1730-1745. [PMID: 32924333 DOI: 10.1002/aur.2369] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 06/22/2020] [Accepted: 06/26/2020] [Indexed: 11/12/2022]
Abstract
This multimodal imaging study used magnetoencephalography, diffusion magnetic resonance imaging (MRI), and gamma-aminobutyric acid (GABA) magnetic resonance spectroscopy (MRS) to identify and contrast the multiple physiological mechanisms associated with auditory processing efficiency in typically developing (TD) children and children with autism spectrum disorder (ASD). Efficient transmission of auditory input between the ear and auditory cortex is necessary for rapid encoding of auditory sensory information. It was hypothesized that the M50 auditory evoked response latency would be modulated by white matter microstructure (indexed by diffusion MRI) and by tonic inhibition (indexed by GABA MRS). Participants were 77 children diagnosed with ASD and 40 TD controls aged 7-17 years. A model of M50 latency with auditory radiation fractional anisotropy and age as independent variables was able to predict 52% of M50 latency variance in TD children, but only 12% of variance in ASD. The ASD group exhibited altered patterns of M50 latency modulation characterized by both higher variance and deviation from the expected structure-function relationship established with the TD group. The TD M50 latency model was used to identify a subpopulation of ASD who are significant "outliers" to the TD model. The ASD outlier group exhibited unexpectedly long M50 latencies in conjunction with significantly lower GABA levels. These findings indicate the dependence of electrophysiologic sensory response latency on underlying microstructure (white matter) and neurochemistry (synaptic activity). This study demonstrates the use of biologically based measures to stratify ASD according to their brain-level "building blocks" as an alternative to their behavioral phenotype. LAY SUMMARY: Children with ASD often have a slower brain response when hearing sounds. This study used multiple brain imaging techniques to examine the structural and neurochemical factors which control the brain's response time to auditory tones in children with ASD and TD children. The relationship between brain imaging measures and brain response time was also used to identify ASD subgroups. Autism Res 2020, 13: 1730-1745. © 2020 International Society for Autism Research and Wiley Periodicals LLC.
Collapse
Affiliation(s)
- Timothy P L Roberts
- Department of Radiology, Lurie Family Foundations MEG Imaging Center, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA.,Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Luke Bloy
- Department of Radiology, Lurie Family Foundations MEG Imaging Center, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Matt Ku
- Department of Radiology, Lurie Family Foundations MEG Imaging Center, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Lisa Blaskey
- Department of Radiology, Lurie Family Foundations MEG Imaging Center, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA.,Department of Child and Adolescent Psychiatry and Behavioral Sciences, Center for Autism Research, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Carissa R Jackel
- Department of Radiology, Lurie Family Foundations MEG Imaging Center, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA.,Division of Developmental and Behavioral Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - James Christopher Edgar
- Department of Radiology, Lurie Family Foundations MEG Imaging Center, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA.,Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Jeffrey I Berman
- Department of Radiology, Lurie Family Foundations MEG Imaging Center, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA.,Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| |
Collapse
|
49
|
Saluja D, Bar-On T, Hayam G, Kassotis J, Kostis WJ, Coromilas J. The Rapid Prediction of Focal Wavefront Origins: Integration With a 3-Dimensional Mapping System. JACC Clin Electrophysiol 2020; 6:1478-1487. [PMID: 33213807 DOI: 10.1016/j.jacep.2020.05.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 05/20/2020] [Accepted: 05/20/2020] [Indexed: 10/23/2022]
Abstract
OBJECTIVES This study assessed the accuracy of an algorithm that predicts the origin of focal arrhythmias using a limited number of data points. BACKGROUND Despite advances in technology, ablations can be time-consuming, and activation mapping continues to have inherent limitations. The authors developed an algorithm that can predict the origin of a focal wavefront using the location and activation timing information in 2 pairs of sampled points. This algorithm was incorporated into an electroanatomic mapping (EAM) system to assess its accuracy in a 3-dimensional clinical environment. METHODS EAM data from patients who underwent successful ablation of a focal wavefront using the CARTO3 system were loaded onto an offline version of the software modified to contain the algorithm. Prediction curves were retrospectively generated. Predictive accuracy, defined as the distance between true and predicted origin wavefront origins, was measured. RESULTS Seventeen wavefronts in as many patients (2 with atrial tachycardia, 3 with orthodromic re-entrant tachycardia, 8 with premature ventricular complex and/or ventricular tachycardia, 4 with focal pulmonary vein isolation breakthroughs) were studied. Thirty-three origin predictions were attempted (1.9 ± 0.4 per patient) using 132 points. Predictions were successfully calculated in 31 of 33 (93.9%) attempts and were accurate to within 5.7 ± 6.9 mm. Individual prediction curves were accurate to within 3.0 ± 4.7 mm. CONCLUSIONS Focal wavefront origins may be accurately predicted in 3 dimensions using a novel algorithm incorporated into an EAM system.
Collapse
Affiliation(s)
- Deepak Saluja
- Department of Medicine, Columbia University, New York, New York, USA.
| | | | | | - John Kassotis
- Department of Medicine, Rutgers-Robert Wood Johnson Medical School, New Brunswick, New Jersey, USA
| | - William J Kostis
- Department of Medicine, Rutgers-Robert Wood Johnson Medical School, New Brunswick, New Jersey, USA
| | - James Coromilas
- Department of Medicine, Rutgers-Robert Wood Johnson Medical School, New Brunswick, New Jersey, USA
| |
Collapse
|
50
|
Saadeh K, Achercouk Z, Fazmin IT, Nantha Kumar N, Salvage SC, Edling CE, Huang CLH, Jeevaratnam K. Protein expression profiles in murine ventricles modeling catecholaminergic polymorphic ventricular tachycardia: effects of genotype and sex. Ann N Y Acad Sci 2020; 1478:63-74. [PMID: 32713021 DOI: 10.1111/nyas.14426] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 05/27/2020] [Accepted: 06/15/2020] [Indexed: 12/12/2022]
Abstract
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is associated with mutations in the cardiac ryanodine receptor (RyR2). These result in stress-induced ventricular arrhythmic episodes, with clinical symptoms and prognosis reported more severe in male than female patients. Murine homozygotic RyR2-P2328S (RyR2S/S ) hearts replicate the proarrhythmic CPVT phenotype of abnormal sarcoplasmic reticular Ca2+ leak and disrupted Ca2+ homeostasis. In addition, RyR2S/S hearts show decreased myocardial action potential conduction velocities (CV), all features implicated in arrhythmic trigger and substrate. The present studies explored for independent and interacting effects of RyR2S/S genotype and sex on expression levels of molecular determinants of Ca2+ homeostasis (CASQ2, FKBP12, SERCA2a, NCX1, and CaV 1.2) and CV (NaV 1.5, Connexin (Cx)-43, phosphorylated-Cx43, and TGF-β1) in mice. Expression levels of Ca2+ homeostasis proteins were not altered, hence implicating abnormal RyR2 function alone in disrupted cytosolic Ca2+ homeostasis. Furthermore, altered NaV 1.5, phosphorylated Cx43, and TGF-β1 expression were not implicated in the development of slowed CV. By contrast, decreased Cx43 expression correlated with slowed CV, in female, but not male, RyR2S/S mice. The CV changes may reflect acute actions of the increased cytosolic Ca2+ on NaV 1.5 and Cx43 function.
Collapse
Affiliation(s)
- Khalil Saadeh
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom.,School of Clinical Medicine, Addenbrooke's Hospital, University of Cambridge, Cambridge, United Kingdom
| | - Zakaria Achercouk
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Ibrahim T Fazmin
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom.,School of Clinical Medicine, Addenbrooke's Hospital, University of Cambridge, Cambridge, United Kingdom
| | - Nakulan Nantha Kumar
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom.,Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Samantha C Salvage
- Physiological Laboratory, University of Cambridge, Cambridge, United Kingdom.,Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Charlotte E Edling
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Christopher L-H Huang
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom.,Physiological Laboratory, University of Cambridge, Cambridge, United Kingdom.,Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Kamalan Jeevaratnam
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom.,Physiological Laboratory, University of Cambridge, Cambridge, United Kingdom
| |
Collapse
|