1
|
Zabrodska E, Kvasilova A, Sedmera D, Olejnickova V. Electrical remodeling of atrioventricular junction: a study on retrogradely perfused chick embryonic heart. Am J Physiol Heart Circ Physiol 2024; 327:H555-H564. [PMID: 39028286 PMCID: PMC11427115 DOI: 10.1152/ajpheart.00115.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 07/10/2024] [Accepted: 07/12/2024] [Indexed: 07/20/2024]
Abstract
Atrioventricular (AV) accessory pathways (APs) provide additional electrical connections between the atria and ventricles, resulting in severe electrical disturbances. It is generally accepted that APs originate in the altered annulus fibrosus maturation in the late prenatal and perinatal period. However, current experimental methods cannot address their development in specific locations around the annulus fibrosus because of the inaccessibility of late fetal hearts for electrophysiological investigation under physiological conditions. In this study, we describe an approach for optical mapping of the retrogradely perfused chick heart in the last third of the incubation period. This system showed stability for electrophysiological measurement for several hours. This feature allowed analysis of the number and functionality of the APs separately in each clinically relevant position. Under physiological conditions, we also recorded the shortening of the AV delay with annulus fibrosus maturation and analyzed ventricular activation patterns after conduction through APs at specific locations. We observed a gradual regression of AP with an area-specific rate (left-sided APs disappeared first). The results also revealed a sudden drop in the number of active APs between embryonic days 16 and 18. Accessory myocardial AV connections were histologically documented in all positions around the annulus fibrosus even after hatching. The fact that no electrically active AP was present at this stage highlights the necessity of electrophysiological evaluation of accessory atrioventricular connections in studying AP formation.NEW & NOTEWORTHY We present the use of retrograde perfusion and optical mapping to investigate, for the first time, the regression of accessory pathways during annulus fibrosus maturation, separately examining each clinically relevant location. The system enables measurements under physiological conditions and demonstrates long-lasting stability compared with other approaches. This study offers applications of the model to investigate electrical and/or functional development in late embryonic development without concern about heart viability.
Collapse
Affiliation(s)
- Eva Zabrodska
- Institute of Anatomy, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Alena Kvasilova
- Institute of Anatomy, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - David Sedmera
- Institute of Anatomy, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Veronika Olejnickova
- Institute of Anatomy, First Faculty of Medicine, Charles University, Prague, Czech Republic
| |
Collapse
|
2
|
Martinez KN, Gerstner NC, Yang SJ, Miller EW. Extended voltage imaging in cardiomyocytes with a triplet state quencher-stabilized silicon rhodamine. Bioorg Med Chem Lett 2024; 109:129842. [PMID: 38844174 DOI: 10.1016/j.bmcl.2024.129842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 05/17/2024] [Accepted: 06/02/2024] [Indexed: 06/18/2024]
Abstract
Voltage imaging of cardiac electrophysiology with voltage-sensitive dyes has long been a powerful complement to traditional methods like patch-clamp electrophysiology. Chemically synthesized voltage sensitive fluorophores offer flexibility for imaging in sensitive samples like human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs), since they do not require genetic transformation of the sample. One serious concern for any fluorescent voltage indicator, whether chemically synthesized or genetically encoded, is phototoxicity. We have been exploring self-healing fluorophores that use triplet state quenchers (TSQs) as a means to reduce the already low phototoxicity of VoltageFluor dyes developed in our lab. We previously showed that conjugation of the TSQ cyclooctatetraene (COT) to a fluorescein based VoltageFluor dye substantially reduced phototoxicity. Here, we show that this approach can be applied to far-red Silicon rhodamine dyes. COT-conjugated Si-rhodamines show improved photostability and reduced phototoxicity in hiPSC-CMs compared to the unmodified dye. This enables imaging of hiPSC-CMs for up to 30 min with continuous illumination. We show that this effect is mediated by a combination of reduced singlet oxygen production and lower loading in the cellular membrane. We discuss future applications and avenues of improvement for TSQ-stabilized VoltageFluor dyes.
Collapse
Affiliation(s)
- Kayli N Martinez
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720-1460, USA
| | - Nels C Gerstner
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720-1460, USA
| | - Samantha J Yang
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720-1460, USA
| | - Evan W Miller
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720-1460, USA; Department of Molecular & Cell Biology, University of California, Berkeley, Berkeley, CA 94720-1460, USA; Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720-1460, USA.
| |
Collapse
|
3
|
Yang C, Cheng Z, Li P, Tian B. Exploring Present and Future Directions in Nano-Enhanced Optoelectronic Neuromodulation. Acc Chem Res 2024; 57:1398-1410. [PMID: 38652467 DOI: 10.1021/acs.accounts.4c00086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2024]
Abstract
Electrical neuromodulation has achieved significant translational advancements, including the development of deep brain stimulators for managing neural disorders and vagus nerve stimulators for seizure treatment. Optoelectronics, in contrast to wired electrical systems, offers the leadless feature that guides multisite and high spatiotemporal neural system targeting, ensuring high specificity and precision in translational therapies known as "photoelectroceuticals". This Account provides a concise overview of developments in novel optoelectronic nanomaterials that are engineered through innovative molecular, chemical, and nanostructure designs to facilitate neural interfacing with high efficiency and minimally invasive implantation.This Account outlines the progress made both within our laboratory and across the broader scientific community, with particular attention to implications in materials innovation strategies, studying bioelectrical activation with spatiotemporal methods, and applications in regenerative medicine. In materials innovation, we highlight a nongenetic, biocompatible, and minimally invasive approach for neuromodulation that spans various length scales, from single neurons to nerve tissues using nanosized particles and monolithic membranes. Furthermore, our discussion exposes the critical unresolved questions in the field, including mechanisms of interaction at the nanobio interface, the precision of cellular or tissue targeting, and integration into existing neural networks with high spatiotemporal modulation. In addition, we present the challenges and pressing needs for long-term stability and biocompatibility, scalability for clinical applications, and the development of noninvasive monitoring and control systems.In addressing the existing challenges in the field of nanobio interfaces, particularly for neural applications, we envisage promising strategic directions that could significantly advance this burgeoning domain. This involves a deeper theoretical understanding of nanobiointerfaces, where simulations and experimental validations on how nanomaterials interact spatiotemporally with biological systems are crucial. The development of more durable materials is vital for prolonged applications in dynamic neural interfaces, and the ability to manipulate neural activity with high specificity and spatial resolution, paves the way for targeting individual neurons or specific neural circuits. Additionally, integrating these interfaces with advanced control systems, possibly leveraging artificial intelligence and machine learning algorithms and programming dynamically responsive materials designs, could significantly ease the implementation of stimulation and recording. These innovations hold the potential to introduce novel treatment modalities for a wide range of neurological and systemic disorders.
Collapse
Affiliation(s)
- Chuanwang Yang
- The James Franck Institute, The University of Chicago, Chicago, Illinois 60637, United States
| | - Zhe Cheng
- Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, United States
| | - Pengju Li
- Pritzker School of Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, United States
| | - Bozhi Tian
- The James Franck Institute, The University of Chicago, Chicago, Illinois 60637, United States
- Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, United States
- The Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, United States
| |
Collapse
|
4
|
Iravanian S, Uzelac I, Shah AD, Toye MJ, Lloyd MS, Burke MA, Daneshmand MA, Attia TS, Vega JD, El-Chami MF, Merchant FM, Cherry EM, Bhatia NK, Fenton FH. Complex repolarization dynamics in ex vivo human ventricles are independent of the restitution properties. Europace 2023; 25:euad350. [PMID: 38006390 PMCID: PMC10751849 DOI: 10.1093/europace/euad350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Accepted: 11/13/2023] [Indexed: 11/27/2023] Open
Abstract
AIMS The mechanisms of transition from regular rhythms to ventricular fibrillation (VF) are poorly understood. The concordant to discordant repolarization alternans pathway is extensively studied; however, despite its theoretical centrality, cannot guide ablation. We hypothesize that complex repolarization dynamics, i.e. oscillations in the repolarization phase of action potentials with periods over two of classic alternans, is a marker of electrically unstable substrate, and ablation of these areas has a stabilizing effect and may reduce the risk of VF. To prove the existence of higher-order periodicities in human hearts. METHODS AND RESULTS We performed optical mapping of explanted human hearts obtained from recipients of heart transplantation at the time of surgery. Signals recorded from the right ventricle endocardial surface were processed to detect global and local repolarization dynamics during rapid pacing. A statistically significant global 1:4 peak was seen in three of six hearts. Local (pixel-wise) analysis revealed the spatially heterogeneous distribution of Periods 4, 6, and 8, with the regional presence of periods greater than two in all the hearts. There was no significant correlation between the underlying restitution properties and the period of each pixel. CONCLUSION We present evidence of complex higher-order periodicities and the co-existence of such regions with stable non-chaotic areas in ex vivo human hearts. We infer that the oscillation of the calcium cycling machinery is the primary mechanism of higher-order dynamics. These higher-order regions may act as niduses of instability and may provide targets for substrate-based ablation of VF.
Collapse
Affiliation(s)
- Shahriar Iravanian
- Department of Medicine, Division of Cardiology, Emory University School of Medicine, 1364 Clifton Road, Atlanta, GA 30322, USA
| | - Ilija Uzelac
- Georgia Institute of Technology, Department of Physics, 837 State St NW, Atlanta, GA 30332, USA
| | - Anand D Shah
- Department of Medicine, Division of Cardiology, Emory University School of Medicine, 1364 Clifton Road, Atlanta, GA 30322, USA
| | - Mikael J Toye
- Georgia Institute of Technology, Department of Physics, 837 State St NW, Atlanta, GA 30332, USA
| | - Michael S Lloyd
- Department of Medicine, Division of Cardiology, Emory University School of Medicine, 1364 Clifton Road, Atlanta, GA 30322, USA
| | - Michael A Burke
- Department of Medicine, Division of Cardiology, Emory University School of Medicine, 1364 Clifton Road, Atlanta, GA 30322, USA
| | - Mani A Daneshmand
- Department of Surgery, Division of Cardiovascular Surgery, Emory University School of Medicine, 1364 Clifton Road, Atlanta, GA 30322, USA
| | - Tamer S Attia
- Department of Surgery, Division of Cardiovascular Surgery, Emory University School of Medicine, 1364 Clifton Road, Atlanta, GA 30322, USA
| | - John David Vega
- Department of Surgery, Division of Cardiovascular Surgery, Emory University School of Medicine, 1364 Clifton Road, Atlanta, GA 30322, USA
| | - Mikhael F El-Chami
- Department of Medicine, Division of Cardiology, Emory University School of Medicine, 1364 Clifton Road, Atlanta, GA 30322, USA
| | - Faisal M Merchant
- Department of Medicine, Division of Cardiology, Emory University School of Medicine, 1364 Clifton Road, Atlanta, GA 30322, USA
| | - Elizabeth M Cherry
- Georgia Institute of Technology, Department of Physics, 837 State St NW, Atlanta, GA 30332, USA
| | - Neal K Bhatia
- Department of Medicine, Division of Cardiology, Emory University School of Medicine, 1364 Clifton Road, Atlanta, GA 30322, USA
| | - Flavio H Fenton
- Georgia Institute of Technology, Department of Physics, 837 State St NW, Atlanta, GA 30332, USA
| |
Collapse
|
5
|
Zhang H, Patton HN, Wood GA, Yan P, Loew LM, Acker CD, Walcott GP, Rogers JM. Optical mapping of cardiac electromechanics in beating in vivo hearts. Biophys J 2023; 122:4207-4219. [PMID: 37775969 PMCID: PMC10645561 DOI: 10.1016/j.bpj.2023.09.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 08/31/2023] [Accepted: 09/26/2023] [Indexed: 10/01/2023] Open
Abstract
Optical mapping has been widely used in the study of cardiac electrophysiology in motion-arrested, ex vivo heart preparations. Recent developments in motion artifact mitigation techniques have made it possible to optically map beating ex vivo hearts, enabling the study of cardiac electromechanics using optical mapping. However, the ex vivo setting imposes limitations on optical mapping such as altered metabolic states, oversimplified mechanical loads, and the absence of neurohormonal regulation. In this study, we demonstrate optical electromechanical mapping in an in vivo heart preparation. Swine hearts were exposed via median sternotomy. Voltage-sensitive dye, either di-4-ANEQ(F)PTEA or di-5-ANEQ(F)PTEA, was injected into the left anterior descending artery. Fluorescence was excited by alternating green and amber light for excitation ratiometry. Cardiac motion during sinus and paced rhythm was tracked using a marker-based method. Motion tracking and excitation ratiometry successfully corrected most motion artifact in the membrane potential signal. Marker-based motion tracking also allowed simultaneous measurement of epicardial deformation. Reconstructed membrane potential and mechanical deformation measurements were validated using monophasic action potentials and sonomicrometry, respectively. Di-5-ANEQ(F)PTEA produced longer working time and higher signal/noise ratio than di-4-ANEQ(F)PTEA. In addition, we demonstrate potential applications of the new optical mapping system including electromechanical mapping during vagal nerve stimulation, fibrillation/defibrillation. and acute regional ischemia. In conclusion, although some technical limitations remain, optical mapping experiments that simultaneously image electrical and mechanical function can be conducted in beating, in vivo hearts.
Collapse
Affiliation(s)
- Hanyu Zhang
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama
| | - Haley N Patton
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama
| | - Garrett A Wood
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama
| | - Ping Yan
- R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut School of Medicine, Farmington, Connecticut
| | - Leslie M Loew
- R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut School of Medicine, Farmington, Connecticut
| | - Corey D Acker
- R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut School of Medicine, Farmington, Connecticut
| | - Gregory P Walcott
- Department of Medicine, Division of Cardiovascular Disease, University of Alabama at Birmingham, Birmingham, Alabama
| | - Jack M Rogers
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama.
| |
Collapse
|
6
|
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] [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
|
7
|
Iravanian S, Uzelac I, Shah AD, Toye MJ, Lloyd MS, Burke MA, Daneshmand MA, Attia TS, Vega JD, El-Chami M, Merchant FM, Cherry EM, Bhatia NK, Fenton FH. Higher-Order Dynamics Beyond Repolarization Alternans in Ex-Vivo Human Ventricles are Independent of the Restitution Properties. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.08.16.23293853. [PMID: 37662394 PMCID: PMC10473769 DOI: 10.1101/2023.08.16.23293853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
Background Repolarization alternans, defined as period-2 oscillation in the repolarization phase of the action potentials, provides a mechanistic link between cellular dynamics and ventricular fibrillation (VF). Theoretically, higher-order periodicities (e.g., periods 4, 6, 8,...) are expected but have minimal experimental evidence. Methods We studied explanted human hearts obtained from recipients of heart transplantation at the time of surgery. Optical mapping of the transmembrane potential was performed after staining the hearts with voltage-sensitive fluorescent dyes. Hearts were stimulated at an increasing rate until VF was induced. Signals recorded from the right ventricle endocardial surface prior to induction of VF and in the presence of 1:1 conduction were processed using the Principal Component Analysis and a combinatorial algorithm to detect and quantify higher-order dynamics. Results were correlated to the underlying electrophysiological characteristics as quantified by restitution curves and conduction velocity. Results A prominent and statistically significant global 1:4 peak (corresponding to period-4 dynamics) was seen in three of the six studied hearts. Local (pixel-wise) analysis revealed the spatially heterogeneous distribution of periods 4, 6, and 8, with the regional presence of periods greater than two in all the hearts. There was no significant correlation between the underlying restitution properties and the period of each pixel. Discussion We present evidence of higher-order periodicities and the co-existence of such regions with stable non-chaotic areas in ex-vivo human hearts. We infer from the independence of the period to the underlying restitution properties that the oscillation of the excitation-contraction coupling and calcium cycling mechanisms is the primary mechanism of higher-order dynamics. These higher-order regions may act as niduses of instability that can degenerate into chaotic fibrillation and may provide targets for substrate-based ablation of VF.
Collapse
Affiliation(s)
- Shahriar Iravanian
- Department of Cardiovascular Medicine, Emory University School of Medicine, Atlanta, GA
| | - Ilija Uzelac
- Georgia Tech, Department of Physics, Atlanta, GA
| | - Anand D Shah
- Department of Cardiovascular Medicine, Emory University School of Medicine, Atlanta, GA
| | | | - Michael S. Lloyd
- Department of Cardiovascular Medicine, Emory University School of Medicine, Atlanta, GA
| | - Michael A. Burke
- Department of Cardiovascular Medicine, Emory University School of Medicine, Atlanta, GA
| | - Mani A Daneshmand
- Division of Cardiovascular Surgery, Department of Surgery, Emory University School of Medicine, Atlanta, GA
| | - Tamer S Attia
- Division of Cardiovascular Surgery, Department of Surgery, Emory University School of Medicine, Atlanta, GA
| | - J David Vega
- Division of Cardiovascular Surgery, Department of Surgery, Emory University School of Medicine, Atlanta, GA
| | - Michael El-Chami
- Department of Cardiovascular Medicine, Emory University School of Medicine, Atlanta, GA
| | - Faisal M. Merchant
- Department of Cardiovascular Medicine, Emory University School of Medicine, Atlanta, GA
| | | | - Neal K. Bhatia
- Department of Cardiovascular Medicine, Emory University School of Medicine, Atlanta, GA
| | | |
Collapse
|
8
|
Zhang H, Patton HN, Nagahawatte ND, Athavale ON, Walcott GP, Cheng LK, Rogers JM. Optical Mapping of Virtual Electrode Polarization Pattern and Its Relationship with Pacemaker Location during Gastric Pacing . ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2023; 2023:1-4. [PMID: 38082999 DOI: 10.1109/embc40787.2023.10340002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2023]
Abstract
Gastric rhythmic contractions are regulated by bioelectrical events known as slow waves (SW). Abnormal SW activity is associated with gastric motility disorders. Gastric pacing is a potential treatment method to restore rhythmic SW activity. However, to date, the efficacy of gastric pacing is inconsistent and the underlying mechanisms of gastric pacing are poorly understood. Optical mapping is widely used in cardiac electrophysiology studies. Its immunity to pacing artifacts offers a distinct advantage over conventional electrical mapping for studying pacing. In the present study, we first found that optical mapping can image pacing-induced virtual electrode polarization patterns in the stomach (adjacent regions of depolarized and hyperpolarized tissue). Second, we found that elicited SWs usually (15 of 16) originated from the depolarized areas of the stimulated region (virtual cathodes). To our knowledge, this is the first direct observation of virtual electrode polarization patterns in the stomach. Conclusions: Optical mapping can image virtual electrode polarization patterns during gastric pacing with high spatial resolution.Clinical Relevance- Gastric pacing is a potential therapeutic method for gastric motility disorders. This study provides direct observation of virtual electrode polarization pattern during gastric pacing and improves our understanding of the mechanisms underlying gastric pacing..
Collapse
|
9
|
Zhang H, Patton HN, Wood GA, Yan P, Loew LM, Acker CD, Walcott GP, Rogers JM. Di-5-ANEQ(F)PTEA Offers Better Performance than Di-4-ANEQ(F)PTEA for In-Situ Cardiac Optical Mapping . ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2023; 2023:1-4. [PMID: 38082915 DOI: 10.1109/embc40787.2023.10340445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2023]
Abstract
Cardiac optical mapping has traditionally been performed in ex-vivo, motion-arrested hearts. Recently, in-situ cardiac optical mapping has been made possible by both motion correction techniques and long-wavelength voltage sensitive dyes (VSDs). However, VSDs have been observed to wash out quickly from blood-perfused in-situ hearts. In this study, we evaluate the performance of a newly developed VSD, di-5-ANEQ(F)PTEA, relative to an earlier VSD, di-4-ANEQ(F)PTEA. We find that di-5-ANEQ(F)PTEA persists over 3 times longer, produces improved signal-to-noise ratio, and does not prolong loading unacceptably.Clinical Relevance-Optical mapping has provided many insights into cardiac arrhythmias, but has traditionally been limited to ex-vivo preparations. The present findings extend the utility of optical mapping in the more realistic in-vivo setting and may eventually enable its use in patients.
Collapse
|
10
|
Lee P, Hou L, Alibhai FJ, Al-attar R, Simón-Chica A, Redondo-Rodríguez A, Nie Y, Mirotsou M, Laflamme MA, Swaminath G, Filgueiras-Rama D. A fully-automated low-cost cardiac monolayer optical mapping robot. Front Cardiovasc Med 2023; 10:1096884. [PMID: 37283579 PMCID: PMC10240081 DOI: 10.3389/fcvm.2023.1096884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Accepted: 04/24/2023] [Indexed: 06/08/2023] Open
Abstract
Scalable and high-throughput electrophysiological measurement systems are necessary to accelerate the elucidation of cardiac diseases in drug development. Optical mapping is the primary method of simultaneously measuring several key electrophysiological parameters, such as action potentials, intracellular free calcium and conduction velocity, at high spatiotemporal resolution. This tool has been applied to isolated whole-hearts, whole-hearts in-vivo, tissue-slices and cardiac monolayers/tissue-constructs. Although optical mapping of all of these substrates have contributed to our understanding of ion-channels and fibrillation dynamics, cardiac monolayers/tissue-constructs are scalable macroscopic substrates that are particularly amenable to high-throughput interrogation. Here, we describe and validate a scalable and fully-automated monolayer optical mapping robot that requires no human intervention and with reasonable costs. As a proof-of-principle demonstration, we performed parallelized macroscopic optical mapping of calcium dynamics in the well-established neonatal-rat-ventricular-myocyte monolayer plated on standard 35 mm dishes. Given the advancements in regenerative and personalized medicine, we also performed parallelized macroscopic optical mapping of voltage dynamics in human pluripotent stem cell-derived cardiomyocyte monolayers using a genetically encoded voltage indictor and a commonly-used voltage sensitive dye to demonstrate the versatility of our system.
Collapse
Affiliation(s)
- Peter Lee
- Novel Arrhythmogenic Mechanisms Program, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
- Essel Research and Development Inc., Toronto, ON, Canada
| | - Luqia Hou
- Cardiometabolic Department, Merck & Co., Inc., South San Francisco, CA, United States
| | - Faisal J. Alibhai
- McEwen Stem Cell Institute, University Health Network, Toronto, ON, Canada
| | - Rasha Al-attar
- McEwen Stem Cell Institute, University Health Network, Toronto, ON, Canada
| | - Ana Simón-Chica
- Novel Arrhythmogenic Mechanisms Program, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
| | - Andrés Redondo-Rodríguez
- Novel Arrhythmogenic Mechanisms Program, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
| | - Yilin Nie
- Cardiometabolic Department, Merck & Co., Inc., South San Francisco, CA, United States
| | - Maria Mirotsou
- Cardiometabolic Department, Merck & Co., Inc., South San Francisco, CA, United States
| | - Michael A. Laflamme
- McEwen Stem Cell Institute, University Health Network, Toronto, ON, Canada
- Peter Munk Cardiac Centre, University Health Network, Toronto, ON, Canada
- Department of Laboratory Medicine & Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Gayathri Swaminath
- Cardiometabolic Department, Merck & Co., Inc., South San Francisco, CA, United States
| | - David Filgueiras-Rama
- Novel Arrhythmogenic Mechanisms Program, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain
- Instituto de Investigación Sanitaria Hospital Clínico San Carlos (IdISSC), Hospital Clínico San Carlos, Madrid, Spain
| |
Collapse
|
11
|
Iravanian S, Uzelac I, Shah AD, Toye MJ, Lloyd MS, Burke MA, Daneshmand MA, Attia TS, Vega JD, Merchant FM, Cherry EM, Bhatia NK, Fenton FH. Beyond Alternans: Detection of Higher-Order Periodicity in Ex-Vivo Human Ventricles Before Induction of Ventricular Fibrillation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.01.539003. [PMID: 37205562 PMCID: PMC10187180 DOI: 10.1101/2023.05.01.539003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Background Repolarization alternans, defined as period-2 oscillation in the repolarization phase of the action potentials, is one of the cornerstones of cardiac electrophysiology as it provides a mechanistic link between cellular dynamics and ventricular fibrillation (VF). Theoretically, higher-order periodicities (e.g., period-4, period-8,...) are expected but have very limited experimental evidence. Methods We studied explanted human hearts, obtained from the recipients of heart transplantation at the time of surgery, using optical mapping technique with transmembrane voltage-sensitive fluorescent dyes. The hearts were stimulated at an increasing rate until VF was induced. The signals recorded from the right ventricle endocardial surface just before the induction of VF and in the presence of 1:1 conduction were processed using the Principal Component Analysis and a combinatorial algorithm to detect and quantify higher-order dynamics. Results A prominent and statistically significant 1:4 peak (corresponding to period-4 dynamics) was seen in three of the six studied hearts. Local analysis revealed the spatiotemporal distribution of higher-order periods. Period-4 was localized to temporally stable islands. Higher-order oscillations (period-5, 6, and 8) were transient and primarily occurred in arcs parallel to the activation isochrones. Discussion We present evidence of higher-order periodicities and the co-existence of such regions with stable non-chaotic areas in ex-vivo human hearts before VF induction. This result is consistent with the period-doubling route to chaos as a possible mechanism of VF initiation, which complements the concordant to discordant alternans mechanism. The presence of higher-order regions may act as niduses of instability that can degenerate into chaotic fibrillation.
Collapse
|
12
|
Kappadan V, Sohi A, Parlitz U, Luther S, Uzelac I, Fenton F, Peters NS, Christoph J, Ng FS. Optical mapping of contracting hearts. J Physiol 2023; 601:1353-1370. [PMID: 36866700 PMCID: PMC10952556 DOI: 10.1113/jp283683] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 02/27/2023] [Indexed: 03/04/2023] Open
Abstract
Optical mapping is a widely used tool to record and visualize the electrophysiological properties in a variety of myocardial preparations such as Langendorff-perfused isolated hearts, coronary-perfused wedge preparations, and cell culture monolayers. Motion artifact originating from the mechanical contraction of the myocardium creates a significant challenge to performing optical mapping of contracting hearts. Hence, to minimize the motion artifact, cardiac optical mapping studies are mostly performed on non-contracting hearts, where the mechanical contraction is removed using pharmacological excitation-contraction uncouplers. However, such experimental preparations eliminate the possibility of electromechanical interaction, and effects such as mechano-electric feedback cannot be studied. Recent developments in computer vision algorithms and ratiometric techniques have opened the possibility of performing optical mapping studies on isolated contracting hearts. In this review, we discuss the existing techniques and challenges of optical mapping of contracting hearts.
Collapse
Affiliation(s)
- Vineesh Kappadan
- National Heart and Lung Institute (NHLI)Imperial College LondonLondonUK
| | - Anies Sohi
- National Heart and Lung Institute (NHLI)Imperial College LondonLondonUK
| | - Ulrich Parlitz
- Biomedical Physcis GroupMax Planck Institute for Dynamics and Self‐OrganizationGöttingenGermany
| | - Stefan Luther
- Biomedical Physcis GroupMax Planck Institute for Dynamics and Self‐OrganizationGöttingenGermany
| | - Ilija Uzelac
- School of PhysicsGeorgia Institute of TechnologyAtlantaGAUSA
| | - Flavio Fenton
- School of PhysicsGeorgia Institute of TechnologyAtlantaGAUSA
| | - Nicholas S Peters
- National Heart and Lung Institute (NHLI)Imperial College LondonLondonUK
| | - Jan Christoph
- Cardiovascular Research InstituteUniversity of CaliforniaSan FranciscoCAUSA
| | - Fu Siong Ng
- National Heart and Lung Institute (NHLI)Imperial College LondonLondonUK
| |
Collapse
|
13
|
Nakao M, Watanabe M, Miquerol L, Natsui H, Koizumi T, Kadosaka T, Koya T, Hagiwara H, Kamada R, Temma T, de Vries AAF, Anzai T. Optogenetic termination of atrial tachyarrhythmias by brief pulsed light stimulation. J Mol Cell Cardiol 2023; 178:9-21. [PMID: 36965700 DOI: 10.1016/j.yjmcc.2023.03.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 03/16/2023] [Accepted: 03/21/2023] [Indexed: 03/27/2023]
Abstract
AIMS The most efficient way to acutely restore sinus rhythm from atrial fibrillation (AF) is electrical cardioversion, which is painful without adequate sedation. Recent studies in various experimental models have indicated that optogenetic termination of AF using light-gated ion channels may provide a myocardium-specific and potentially painless alternative future therapy. However, its underlying mechanism(s) remain(s) incompletely understood. As brief pulsed light stimulation, even without global illumination, can achieve optogenetic AF termination, besides direct conduction block also modulation of action potential (AP) properties may be involved in the termination mechanism. We studied the relationship between optogenetic AP duration (APD) and effective refractory period (ERP) prolongation by brief pulsed light stimulation and termination of atrial tachyarrhythmia (AT). METHODS AND RESULTS Hearts from transgenic mice expressing the H134R variant of channelrhodopsin-2 in atrial myocytes were explanted and perfused retrogradely. AT induced by electrical stimulation was terminated by brief pulsed blue light stimulation (470 nm, 10 ms, 16 mW/mm2) with 68% efficacy. The termination rate was dependent on pulse duration and light intensity. Optogenetically imposed APD and ERP changes were systematically examined and optically monitored. Brief pulsed light stimulation (10 ms, 6 mW/mm2) consistently prolonged APD and ERP when light was applied at different phases of the cardiac action potential. Optical tracing showed light-induced APD prolongation during the termination of AT. CONCLUSION Our results directly demonstrate that cationic channelrhodopsin activation by brief pulsed light stimulation prolongs the atrial refractory period suggesting that this is one of the key mechanisms of optogenetic termination of AT.
Collapse
Affiliation(s)
- Motoki Nakao
- Department of Cardiovascular Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Masaya Watanabe
- Department of Cardiovascular Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan.
| | - Lucile Miquerol
- Developmental Biology Institute of Marseille, Aix-Marseille Université, CNRS UMR 7288, Campus de Luminy Case 907, CEDEX 9, Marseille 13288, France
| | - Hiroyuki Natsui
- Department of Cardiovascular Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Takuya Koizumi
- Department of Cardiovascular Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Takahide Kadosaka
- Department of Cardiovascular Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Taro Koya
- Department of Cardiovascular Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Hikaru Hagiwara
- Department of Cardiovascular Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Rui Kamada
- Department of Cardiovascular Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Taro Temma
- Department of Cardiovascular Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Antoine A F de Vries
- Laboratory of Experimental Cardiology Department of Cardiology, Leiden University Medical Center Leiden, Netherlands
| | - Toshihisa Anzai
- Department of Cardiovascular Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| |
Collapse
|
14
|
Niort BC, Recalde A, Cros C, Brette F. Critical Link between Calcium Regional Heterogeneity and Atrial Fibrillation Susceptibility in Sheep Left Atria. J Clin Med 2023; 12:jcm12030746. [PMID: 36769395 PMCID: PMC9917890 DOI: 10.3390/jcm12030746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 12/30/2022] [Accepted: 01/12/2023] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND Atrial fibrillation is the most sustained form of arrhythmia in the human population that leads to important electrophysiological and structural cardiac remodeling as it progresses into a chronic form. Calcium is an established key player of cellular electrophysiology in the heart, yet to date, there is no information that maps calcium signaling across the left atrium. OBJECTIVE The aim of this study is to determine whether calcium signaling is homogenous throughout the different regions of the left atrium. This work tests the hypothesis that differences across the healthy left atrium contribute to a unique, region-dependent calcium cycling and participates in the pro-arrhythmic activity during atrial fibrillation. METHODS An animal model relevant to human cardiac function (the sheep) was used to characterize both the electrical activity and the calcium signaling of three distinct left atrium regions (appendage, free wall and pulmonary veins) in control conditions and after acetylcholine perfusion (5 μM) to induce acute atrial fibrillation. High-resolution dual calcium-voltage optical mapping on the left atria of sheep was performed to explore the spatiotemporal dynamics of calcium signaling in relation to electrophysiological properties. RESULTS Action potential duration (at 80% repolarization) was not significantly different in the three regions of interest for the three pacing sites. In contrast, the time to 50% calcium transient decay was significantly different depending on the region paced and recorded. Acetylcholine perfusion and burst pacing-induced atrial fibrillation when pulmonary veins and appendage regions were paced but not when the free wall region was. Dantrolene (a ryanodine receptor blocker) did not reduce atrial fibrillation susceptibility. CONCLUSION These data provide the first evidence of heterogenous calcium signaling across the healthy left atrium. Such basal regional differences may be exacerbated during the progression of atrial fibrillation and thus play a crucial role in focal arrhythmia initiation without ryanodine receptor gating modification.
Collapse
Affiliation(s)
- Barbara C. Niort
- Centre de Recherche Cardio-Thoracique de Bordeaux (CRCTB), Inserm U1045, Univeristé de Bordeaux, F-33000 Bordeaux, France
- IHU Liryc, Electrophysiology and Heart Modeling Institute, F-33600 Pessac, France
| | - Alice Recalde
- Centre de Recherche Cardio-Thoracique de Bordeaux (CRCTB), Inserm U1045, Univeristé de Bordeaux, F-33000 Bordeaux, France
- IHU Liryc, Electrophysiology and Heart Modeling Institute, F-33600 Pessac, France
| | - Caroline Cros
- Centre de Recherche Cardio-Thoracique de Bordeaux (CRCTB), Inserm U1045, Univeristé de Bordeaux, F-33000 Bordeaux, France
- IHU Liryc, Electrophysiology and Heart Modeling Institute, F-33600 Pessac, France
| | - Fabien Brette
- Centre de Recherche Cardio-Thoracique de Bordeaux (CRCTB), Inserm U1045, Univeristé de Bordeaux, F-33000 Bordeaux, France
- IHU Liryc, Electrophysiology and Heart Modeling Institute, F-33600 Pessac, France
- Phymedexp Inserm, CNRS, Université de Montpellier, CHRU, F-34295 Montpellier, France
- Correspondence:
| |
Collapse
|
15
|
Amesz JH, Zhang L, Everts BR, De Groot NMS, Taverne YJHJ. Living myocardial slices: Advancing arrhythmia research. Front Physiol 2023; 14:1076261. [PMID: 36711023 PMCID: PMC9880234 DOI: 10.3389/fphys.2023.1076261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 01/04/2023] [Indexed: 01/15/2023] Open
Abstract
Living myocardial slices (LMS) are ultrathin (150-400 µm) sections of intact myocardium that can be used as a comprehensive model for cardiac arrhythmia research. The recent introduction of biomimetic electromechanical cultivation chambers enables long-term cultivation and easy control of living myocardial slices culture conditions. The aim of this review is to present the potential of this biomimetic interface using living myocardial slices in electrophysiological studies outlining advantages, disadvantages and future perspectives of the model. Furthermore, different electrophysiological techniques and their application on living myocardial slices will be discussed. The developments of living myocardial slices in electrophysiology research will hopefully lead to future breakthroughs in the understanding of cardiac arrhythmia mechanisms and the development of novel therapeutic options.
Collapse
Affiliation(s)
- Jorik H. Amesz
- Translational Cardiothoracic Surgery Research Lab, Lowlands Institute for Bioelectric Medicine, Department of Cardiothoracic Surgery, Erasmus University Medical Center, Rotterdam, Netherlands
- Translational Electrophysiology, Lowlands Institute for Bioelectric Medicine, Department of Cardiology, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Lu Zhang
- Translational Electrophysiology, Lowlands Institute for Bioelectric Medicine, Department of Cardiology, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Bian R. Everts
- Translational Cardiothoracic Surgery Research Lab, Lowlands Institute for Bioelectric Medicine, Department of Cardiothoracic Surgery, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Natasja M. S. De Groot
- Translational Electrophysiology, Lowlands Institute for Bioelectric Medicine, Department of Cardiology, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Yannick J. H. J. Taverne
- Translational Cardiothoracic Surgery Research Lab, Lowlands Institute for Bioelectric Medicine, Department of Cardiothoracic Surgery, Erasmus University Medical Center, Rotterdam, Netherlands
| |
Collapse
|
16
|
Nagahawatte ND, Cheng LK, Avci R, Angeli-Gordon TR, Paskaranandavadivel N. Systematic review of small intestine pacing parameters for modulation of gut function. Neurogastroenterol Motil 2023; 35:e14473. [PMID: 36194179 PMCID: PMC10078404 DOI: 10.1111/nmo.14473] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Revised: 08/22/2022] [Accepted: 09/12/2022] [Indexed: 12/31/2022]
Abstract
BACKGROUND AND PURPOSE The efficacy of conventional treatments for severe and chronic functional motility disorders remains limited. High-energy pacing is a promising alternative therapy for patients that fail conventional treatment. Pacing primarily regulates gut motility by modulating rhythmic bio-electrical events called slow waves. While the efficacy of this technique has been widely investigated on the stomach, its application in the small intestine is less developed. This systematic review was undertaken to summarize the status of small intestinal pacing and evaluate its efficacy in modulating bowel function through preclinical research studies. METHODS The literature was searched using Scopus, PubMed, Ovid, Cochrane, CINAHL, and Google Scholar. Studies investigating electrophysiological, motility, and/or nutrient absorption responses to pacing were included. A critical review of all included studies was conducted comparing study outcomes against experimental protocols. RESULTS The inclusion criteria were met by 34 publications. A range of pacing parameters including amplitude, pulse width, pacing direction, and its application to broad regional small intestinal segments were identified and assessed. Out of the 34 studies surveyed, 20/23 studies successfully achieved slow-wave entrainment, 9/11 studies enhanced nutrient absorption and 21/27 studies modulated motility with pacing. CONCLUSION Small intestine pacing shows therapeutic potential in treating disorders such as short bowel syndrome and obesity. This systematic review proposes standardized protocols to maximize research outcomes and thereby translate to human studies for clinical validation. The use of novel techniques such as high-resolution electrical, manometric, and optical mapping in future studies will enable a mechanistic understanding of pacing.
Collapse
Affiliation(s)
- Nipuni D Nagahawatte
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Leo K Cheng
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand.,Department of Surgery, Vanderbilt University, Nashville, Tennessee, USA.,Riddet Institute Centre of Research Excellence, Palmerston North, New Zealand
| | - Recep Avci
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Timothy R Angeli-Gordon
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand.,Department of Surgery, University of Auckland, Auckland, New Zealand
| | | |
Collapse
|
17
|
Hu H, Huang H, Li M, Gao X, Yin L, Qi R, Wu RS, Chen X, Ma Y, Shi K, Li C, Maus TM, Huang B, Lu C, Lin M, Zhou S, Lou Z, Gu Y, Chen Y, Lei Y, Wang X, Wang R, Yue W, Yang X, Bian Y, Mu J, Park G, Xiang S, Cai S, Corey PW, Wang J, Xu S. A wearable cardiac ultrasound imager. Nature 2023; 613:667-675. [PMID: 36697864 PMCID: PMC9876798 DOI: 10.1038/s41586-022-05498-z] [Citation(s) in RCA: 109] [Impact Index Per Article: 109.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 10/31/2022] [Indexed: 01/26/2023]
Abstract
Continuous imaging of cardiac functions is highly desirable for the assessment of long-term cardiovascular health, detection of acute cardiac dysfunction and clinical management of critically ill or surgical patients1-4. However, conventional non-invasive approaches to image the cardiac function cannot provide continuous measurements owing to device bulkiness5-11, and existing wearable cardiac devices can only capture signals on the skin12-16. Here we report a wearable ultrasonic device for continuous, real-time and direct cardiac function assessment. We introduce innovations in device design and material fabrication that improve the mechanical coupling between the device and human skin, allowing the left ventricle to be examined from different views during motion. We also develop a deep learning model that automatically extracts the left ventricular volume from the continuous image recording, yielding waveforms of key cardiac performance indices such as stroke volume, cardiac output and ejection fraction. This technology enables dynamic wearable monitoring of cardiac performance with substantially improved accuracy in various environments.
Collapse
Affiliation(s)
- Hongjie Hu
- Department of Nanoengineering, University of California San Diego, La Jolla, CA, USA
| | - Hao Huang
- Department of Nanoengineering, University of California San Diego, La Jolla, CA, USA
| | - Mohan Li
- Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, CA, USA
| | - Xiaoxiang Gao
- Department of Nanoengineering, University of California San Diego, La Jolla, CA, USA
| | - Lu Yin
- Department of Nanoengineering, University of California San Diego, La Jolla, CA, USA
| | - Ruixiang Qi
- Department of Computer Science and Engineering, University of California San Diego, La Jolla, CA, USA
| | - Ray S Wu
- Department of Nanoengineering, University of California San Diego, La Jolla, CA, USA
| | - Xiangjun Chen
- Materials Science and Engineering Program, University of California San Diego, La Jolla, CA, USA
| | - Yuxiang Ma
- Department of Nanoengineering, University of California San Diego, La Jolla, CA, USA
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Keren Shi
- Materials Science and Engineering Program, University of California San Diego, La Jolla, CA, USA
- Materials Science and Engineering Program, University of California, Riverside, CA, USA
| | - Chenghai Li
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, CA, USA
| | - Timothy M Maus
- Department of Anesthesiology, University of California, San Diego Health Sulpizio Cardiovascular Center, La Jolla, CA, USA
| | - Brady Huang
- Department of Radiology, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Chengchangfeng Lu
- Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, CA, USA
| | - Muyang Lin
- Department of Nanoengineering, University of California San Diego, La Jolla, CA, USA
| | - Sai Zhou
- Materials Science and Engineering Program, University of California San Diego, La Jolla, CA, USA
| | - Zhiyuan Lou
- Department of Nanoengineering, University of California San Diego, La Jolla, CA, USA
| | - Yue Gu
- Materials Science and Engineering Program, University of California San Diego, La Jolla, CA, USA
- Department of Neurosurgery, Yale University, New Haven, CT, USA
| | - Yimu Chen
- Department of Nanoengineering, University of California San Diego, La Jolla, CA, USA
| | - Yusheng Lei
- Department of Nanoengineering, University of California San Diego, La Jolla, CA, USA
- Department of Chemical Engineering, Stanford University, Stanford, CA, USA
| | - Xinyu Wang
- Department of Nanoengineering, University of California San Diego, La Jolla, CA, USA
| | - Ruotao Wang
- Department of Nanoengineering, University of California San Diego, La Jolla, CA, USA
| | - Wentong Yue
- Department of Nanoengineering, University of California San Diego, La Jolla, CA, USA
| | - Xinyi Yang
- Materials Science and Engineering Program, University of California San Diego, La Jolla, CA, USA
| | - Yizhou Bian
- Department of Nanoengineering, University of California San Diego, La Jolla, CA, USA
| | - Jing Mu
- Materials Science and Engineering Program, University of California San Diego, La Jolla, CA, USA
| | - Geonho Park
- Department of Nanoengineering, University of California San Diego, La Jolla, CA, USA
| | - Shu Xiang
- Softsonics, Inc., San Diego, CA, USA
| | - Shengqiang Cai
- Materials Science and Engineering Program, University of California San Diego, La Jolla, CA, USA
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, CA, USA
| | - Paul W Corey
- Department of Anesthesiology, Sharp Memorial Hospital, San Diego, CA, USA
| | - Joseph Wang
- Department of Nanoengineering, University of California San Diego, La Jolla, CA, USA
- Materials Science and Engineering Program, University of California San Diego, La Jolla, CA, USA
| | - Sheng Xu
- Department of Nanoengineering, University of California San Diego, La Jolla, CA, USA.
- Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, CA, USA.
- Materials Science and Engineering Program, University of California San Diego, La Jolla, CA, USA.
- Department of Radiology, School of Medicine, University of California San Diego, La Jolla, CA, USA.
- Department of Bioengineering, University of California San Diego, La Jolla, CA, USA.
| |
Collapse
|
18
|
Maltsev VA, Stern MD. The paradigm shift: Heartbeat initiation without "the pacemaker cell". Front Physiol 2022; 13:1090162. [PMID: 36569749 PMCID: PMC9780451 DOI: 10.3389/fphys.2022.1090162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Accepted: 11/23/2022] [Indexed: 12/13/2022] Open
Abstract
The current dogma about the heartbeat origin is based on "the pacemaker cell," a specialized cell residing in the sinoatrial node (SAN) that exhibits spontaneous diastolic depolarization triggering rhythmic action potentials (APs). Recent high-resolution imaging, however, demonstrated that Ca signals and APs in the SAN are heterogeneous, with many cells generating APs of different rates and rhythms or even remaining non-firing (dormant cells), i.e., generating only subthreshold signals. Here we numerically tested a hypothesis that a community of dormant cells can generate normal automaticity, i.e., "the pacemaker cell" is not required to initiate rhythmic cardiac impulses. Our model includes 1) non-excitable cells generating oscillatory local Ca releases and 2) an excitable cell lacking automaticity. While each cell in isolation was not "the pacemaker cell", the cell system generated rhythmic APs: The subthreshold signals of non-excitable cells were transformed into respective membrane potential oscillations via electrogenic Na/Ca exchange and further transferred and integrated (computed) by the excitable cells to reach its AP threshold, generating rhythmic pacemaking. Cardiac impulse is an emergent property of the SAN cellular network and can be initiated by cells lacking intrinsic automaticity. Cell heterogeneity, weak coupling, subthreshold signals, and their summation are critical properties of the new pacemaker mechanism, i.e., cardiac pacemaker can operate via a signaling process basically similar to that of "temporal summation" happening in a neuron with input from multiple presynaptic cells. The new mechanism, however, does not refute the classical pacemaker cell-based mechanism: both mechanisms can co-exist and interact within SAN tissue.
Collapse
|
19
|
Carta-Bergaz A, Ríos-Muñoz GR, Crisóstomo V, Sánchez-Margallo FM, Ledesma-Carbayo MJ, Bermejo-Thomas J, Fernández-Avilés F, Arenal-Maíz Á. Intrapericardial cardiosphere-derived cells hinder epicardial dense scar expansion and promote electrical homogeneity in a porcine post-infarction model. Front Physiol 2022; 13:1041348. [PMID: 36457311 PMCID: PMC9705343 DOI: 10.3389/fphys.2022.1041348] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2022] [Accepted: 10/11/2022] [Indexed: 11/14/2023] Open
Abstract
The arrhythmic substrate of ventricular tachycardias in many structural heart diseases is located in the epicardium, often resulting in poor outcomes with currently available therapies. Cardiosphere-derived cells (CDCs) have been shown to modify myocardial scarring. A total of 19 Large White pigs were infarcted by occlusion of the mid-left anterior descending coronary artery for 150 min. Baseline cardiac magnetic resonance (CMR) imaging with late gadolinium enhancement sequences was obtained 4 weeks post-infarction and pigs were randomized to a treatment group (intrapericardial administration of 300,000 allogeneic CDCs/kg), (n = 10) and to a control group (n = 9). A second CMR and high-density endocardial electroanatomical mapping were performed at 16 weeks post-infarction. After the electrophysiological study, pigs were sacrificed and epicardial optical mapping and histological studies of the heterogeneous tissue of the endocardial and epicardial scars were performed. In comparison with control conditions, intrapericardial CDCs reduced the growth of epicardial dense scar and epicardial electrical heterogeneity. The relative differences in conduction velocity and action potential duration between healthy myocardium and heterogeneous tissue were significantly smaller in the CDC-treated group than in the control group. The lower electrical heterogeneity coincides with heterogeneous tissue with less fibrosis, better cardiomyocyte viability, and a greater quantity and better polarity of connexin 43. At the endocardial level, no differences were detected between groups. Intrapericardial CDCs produce anatomical and functional changes in the epicardial arrhythmic substrate, which could have an anti-arrhythmic effect.
Collapse
Affiliation(s)
- Alejandro Carta-Bergaz
- Gregorio Marañón Health Research Institute (IiSGM), Department of Cardiology, Hospital General Universitario Gregorio Marañón, Madrid, Spain
- Centre for Biomedical Research in Cardiovascular Disease Network (CIBERCV), Madrid, Spain
| | - Gonzalo R. Ríos-Muñoz
- Gregorio Marañón Health Research Institute (IiSGM), Department of Cardiology, Hospital General Universitario Gregorio Marañón, Madrid, Spain
- Centre for Biomedical Research in Cardiovascular Disease Network (CIBERCV), Madrid, Spain
- Department of Bioengineering and Space Engineering, Universidad Carlos III de Madrid, Madrid, Spain
| | - Verónica Crisóstomo
- Centre for Biomedical Research in Cardiovascular Disease Network (CIBERCV), Madrid, Spain
- Jesús Usón Minimally Invasive Surgery Centre, Cáceres, Spain
| | - Francisco M. Sánchez-Margallo
- Centre for Biomedical Research in Cardiovascular Disease Network (CIBERCV), Madrid, Spain
- Jesús Usón Minimally Invasive Surgery Centre, Cáceres, Spain
| | - María J. Ledesma-Carbayo
- Biomedical Image Technologies, ETSI Telecomunicación, Universidad Politécnica de Madrid, Madrid, Spain
- CIBER-BBN, Instituto de Salud Carlos III, Madrid, Spain
| | - Javier Bermejo-Thomas
- Gregorio Marañón Health Research Institute (IiSGM), Department of Cardiology, Hospital General Universitario Gregorio Marañón, Madrid, Spain
- Centre for Biomedical Research in Cardiovascular Disease Network (CIBERCV), Madrid, Spain
- Medical School, Universidad Complutense de Madrid, Madrid, Spain
| | - Francisco Fernández-Avilés
- Gregorio Marañón Health Research Institute (IiSGM), Department of Cardiology, Hospital General Universitario Gregorio Marañón, Madrid, Spain
- Centre for Biomedical Research in Cardiovascular Disease Network (CIBERCV), Madrid, Spain
- Medical School, Universidad Complutense de Madrid, Madrid, Spain
| | - Ángel Arenal-Maíz
- Gregorio Marañón Health Research Institute (IiSGM), Department of Cardiology, Hospital General Universitario Gregorio Marañón, Madrid, Spain
- Centre for Biomedical Research in Cardiovascular Disease Network (CIBERCV), Madrid, Spain
| |
Collapse
|
20
|
Rinella S, Massimino S, Fallica PG, Giacobbe A, Donato N, Coco M, Neri G, Parenti R, Perciavalle V, Conoci S. Emotion Recognition: Photoplethysmography and Electrocardiography in Comparison. BIOSENSORS 2022; 12:811. [PMID: 36290948 PMCID: PMC9599834 DOI: 10.3390/bios12100811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 09/23/2022] [Accepted: 09/26/2022] [Indexed: 06/16/2023]
Abstract
Automatically recognizing negative emotions, such as anger or stress, and also positive ones, such as euphoria, can contribute to improving well-being. In real-life, emotion recognition is a difficult task since many of the technologies used for this purpose in both laboratory and clinic environments, such as electroencephalography (EEG) and electrocardiography (ECG), cannot realistically be used. Photoplethysmography (PPG) is a non-invasive technology that can be easily integrated into wearable sensors. This paper focuses on the comparison between PPG and ECG concerning their efficacy in detecting the psychophysical and affective states of the subjects. It has been confirmed that the levels of accuracy in the recognition of affective variables obtained by PPG technology are comparable to those achievable with the more traditional ECG technology. Moreover, the affective psychological condition of the participants (anxiety and mood levels) may influence the psychophysiological responses recorded during the experimental tests.
Collapse
Affiliation(s)
- Sergio Rinella
- Department of Educational Sciences, University of Catania, via Biblioteca 4, 95124 Catania, Italy
| | - Simona Massimino
- Department of Biomedical and Biotechnological Sciences, Section of Physiology, University of Catania, via S. Sofia 89, 95125 Catania, Italy
| | - Piero Giorgio Fallica
- INSTM (National Interuniversity Consortium of Science and Technology of Materials), via G. Giusti 9, 50121 Firenze, Italy
| | - Alberto Giacobbe
- Department of Engineering, University of Messina, Contrada Di Dio, 98158 Messina, Italy
| | - Nicola Donato
- Department of Engineering, University of Messina, Contrada Di Dio, 98158 Messina, Italy
| | - Marinella Coco
- Department of Educational Sciences, University of Catania, via Biblioteca 4, 95124 Catania, Italy
| | - Giovanni Neri
- Department of Engineering, University of Messina, Contrada Di Dio, 98158 Messina, Italy
| | - Rosalba Parenti
- Department of Biomedical and Biotechnological Sciences, Section of Physiology, University of Catania, via S. Sofia 89, 95125 Catania, Italy
| | - Vincenzo Perciavalle
- Department of Sciences of Life, Kore University of Enna, Cittadella Universitaria, 94100 Enna, Italy
| | - Sabrina Conoci
- Department of Chemical, Biological, Pharmaceutical and Environmental Science, University of Messina, Viale F. Stagno d’Alcontres 31, Vill. S. Agata, 98166 Messina, Italy
- LAB Sense Beyond Nano—URT Department of Sciences Physics and Technologies of Matter (DSFTM) CNR, Viale F. Stagno d’Alcontres 31, Vill. S. Agata, 98166 Messina, Italy
- Department of Chemistry ‘‘Giacomo Ciamician’’, University of Bologna, Via Selmi 2, 40126 Bologna, Italy
- Istituto per la Microelettronica e Microsistemi, Consiglio Nazionale delle Ricerche (CNR-IMM), Strada VIII n. 5, 95121 Catania, Italy
| |
Collapse
|
21
|
Abstract
The global burden caused by cardiovascular disease is substantial, with heart disease representing the most common cause of death around the world. There remains a need to develop better mechanistic models of cardiac function in order to combat this health concern. Heart rhythm disorders, or arrhythmias, are one particular type of disease which has been amenable to quantitative investigation. Here we review the application of quantitative methodologies to explore dynamical questions pertaining to arrhythmias. We begin by describing single-cell models of cardiac myocytes, from which two and three dimensional models can be constructed. Special focus is placed on results relating to pattern formation across these spatially-distributed systems, especially the formation of spiral waves of activation. Next, we discuss mechanisms which can lead to the initiation of arrhythmias, focusing on the dynamical state of spatially discordant alternans, and outline proposed mechanisms perpetuating arrhythmias such as fibrillation. We then review experimental and clinical results related to the spatio-temporal mapping of heart rhythm disorders. Finally, we describe treatment options for heart rhythm disorders and demonstrate how statistical physics tools can provide insights into the dynamics of heart rhythm disorders.
Collapse
Affiliation(s)
- Wouter-Jan Rappel
- Department of Physics, University of California San Diego, La Jolla, CA 92037
| |
Collapse
|
22
|
Siles-Paredes JG, Crowley CJ, Fenton FH, Bhatia N, Iravanian S, Sandoval I, Pollnow S, Dössel O, Salinet J, Uzelac I. Circle Method for Robust Estimation of Local Conduction Velocity High-Density Maps From Optical Mapping Data: Characterization of Radiofrequency Ablation Sites. Front Physiol 2022; 13:794761. [PMID: 36035466 PMCID: PMC9417315 DOI: 10.3389/fphys.2022.794761] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 06/15/2022] [Indexed: 01/10/2023] Open
Abstract
Conduction velocity (CV) slowing is associated with atrial fibrillation (AF) and reentrant ventricular tachycardia (VT). Clinical electroanatomical mapping systems used to localize AF or VT sources as ablation targets remain limited by the number of measuring electrodes and signal processing methods to generate high-density local activation time (LAT) and CV maps of heterogeneous atrial or trabeculated ventricular endocardium. The morphology and amplitude of bipolar electrograms depend on the direction of propagating electrical wavefront, making identification of low-amplitude signal sources commonly associated with fibrotic area difficulty. In comparison, unipolar electrograms are not sensitive to wavefront direction, but measurements are susceptible to distal activity. This study proposes a method for local CV calculation from optical mapping measurements, termed the circle method (CM). The local CV is obtained as a weighted sum of CV values calculated along different chords spanning a circle of predefined radius centered at a CV measurement location. As a distinct maximum in LAT differences is along the chord normal to the propagating wavefront, the method is adaptive to the propagating wavefront direction changes, suitable for electrical conductivity characterization of heterogeneous myocardium. In numerical simulations, CM was validated characterizing modeled ablated areas as zones of distinct CV slowing. Experimentally, CM was used to characterize lesions created by radiofrequency ablation (RFA) on isolated hearts of rats, guinea pig, and explanted human hearts. To infer the depth of RFA-created lesions, excitation light bands of different penetration depths were used, and a beat-to-beat CV difference analysis was performed to identify CV alternans. Despite being limited to laboratory research, studies based on CM with optical mapping may lead to new translational insights into better-guided ablation therapies.
Collapse
Affiliation(s)
- Jimena G. Siles-Paredes
- Graduate Program in Biotechnoscience, Federal University of ABC, São Paulo, Brazil
- HEartLab, Federal University of ABC, São Paulo, Brazil
- *Correspondence: Jimena G. Siles-Paredes,
| | | | - Flavio H. Fenton
- Georgia Institute of Technology, School of Physics, Atlanta, GA, United States
| | - Neal Bhatia
- Division of Cardiology, Section of Electrophysiology, Emory University Hospital, Atlanta, GA, United States
| | - Shahriar Iravanian
- Division of Cardiology, Section of Electrophysiology, Emory University Hospital, Atlanta, GA, United States
| | | | - Stefan Pollnow
- Karlsruhe Institute of Technology (KIT)/Institute of Biomedical Engineering, Karlsruhe, Germany
| | - Olaf Dössel
- Karlsruhe Institute of Technology (KIT)/Institute of Biomedical Engineering, Karlsruhe, Germany
| | - João Salinet
- Graduate Program in Biotechnoscience, Federal University of ABC, São Paulo, Brazil
- HEartLab, Federal University of ABC, São Paulo, Brazil
| | - Ilija Uzelac
- Georgia Institute of Technology, School of Physics, Atlanta, GA, United States
| |
Collapse
|
23
|
Nagahawatte ND, Zhang H, Paskaranandavadivel N, Patton HN, Garrett AS, Angeli-Gordon TR, Nisbet L, Rogers JM, Cheng LK. Gastric pacing response evaluated with simultaneous electrical and optical mapping. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2022; 2022:2224-2227. [PMID: 36086523 DOI: 10.1109/embc48229.2022.9871138] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Gastric pacing is an attractive therapeutic approach for correcting abnormal bioelectrical activity. While high-resolution (HR) electrical mapping techniques have largely contributed to the current understanding of the effect of pacing on the electrophysiological function, these mapping techniques are restricted to surface contact electrodes and the signal quality can be corrupted by pacing artifacts. Optical mapping of voltage sensitive dyes is an alternative approach used in cardiac research, and the signal quality is not affected by pacing artifacts. In this study, we simultaneously applied HR optical and electrical mapping techniques to evaluate the bioelectrical slow wave response to gastric pacing. The studies were conducted in vivo on porcine stomachs ( n=3) where the gastric electrical activity was entrained using high-energy pacing. The pacing response was optically tracked using voltage-sensitive fluorescent dyes and electrically tracked using surface contact electrodes positioned on adjacent regions. Slow waves were captured optically and electrically and were concordant in time and direction of propagation with comparable mean velocities ([Formula: see text]) and periods ([Formula: see text]). Importantly, the optical signals were free from pacing artifacts otherwise induced in electrical recordings highlighting an advantage of optical mapping. Clinical Relevance- Entrainment mapping of gastric pacing using optical techniques is a major advance for improving the preclinical understanding of the therapy. The findings can thereby inform the efficacy of gastric pacing in treating functional motility disorders.
Collapse
|
24
|
Simultaneous triple-parametric optical mapping of transmembrane potential, intracellular calcium and NADH for cardiac physiology assessment. Commun Biol 2022; 5:319. [PMID: 35388167 PMCID: PMC8987030 DOI: 10.1038/s42003-022-03279-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 03/15/2022] [Indexed: 11/08/2022] Open
Abstract
Investigation of the complex relationships and dependencies of multiple cellular processes that govern cardiac physiology and pathophysiology requires simultaneous dynamic assessment of multiple parameters. In this study, we introduce triple-parametric optical mapping to simultaneously image metabolism, electrical excitation, and calcium signaling from the same field of view and demonstrate its application in the field of drug testing and cardiovascular research. We applied this metabolism-excitation-contraction coupling (MECC) methodology to test the effects of blebbistatin, 4-aminopyridine and verapamil on cardiac physiology. While blebbistatin and 4-aminopyridine alter multiple aspects of cardiac function suggesting off-target effects, the effects of verapamil were on-target and it altered only one of ten tested parameters. Triple-parametric optical mapping was also applied during ischemia and reperfusion; and we identified that metabolic changes precede the effects of ischemia on cardiac electrophysiology.
Collapse
|
25
|
Herrero Martin C, Oved A, Chowdhury RA, Ullmann E, Peters NS, Bharath AA, Varela M. EP-PINNs: Cardiac Electrophysiology Characterisation Using Physics-Informed Neural Networks. Front Cardiovasc Med 2022; 8:768419. [PMID: 35187101 PMCID: PMC8850959 DOI: 10.3389/fcvm.2021.768419] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 12/22/2021] [Indexed: 11/13/2022] Open
Abstract
Accurately inferring underlying electrophysiological (EP) tissue properties from action potential recordings is expected to be clinically useful in the diagnosis and treatment of arrhythmias such as atrial fibrillation. It is, however, notoriously difficult to perform. We present EP-PINNs (Physics Informed Neural Networks), a novel tool for accurate action potential simulation and EP parameter estimation from sparse amounts of EP data. We demonstrate, using 1D and 2D in silico data, how EP-PINNs are able to reconstruct the spatio-temporal evolution of action potentials, whilst predicting parameters related to action potential duration (APD), excitability and diffusion coefficients. EP-PINNs are additionally able to identify heterogeneities in EP properties, making them potentially useful for the detection of fibrosis and other localised pathology linked to arrhythmias. Finally, we show EP-PINNs effectiveness on biological in vitro preparations, by characterising the effect of anti-arrhythmic drugs on APD using optical mapping data. EP-PINNs are a promising clinical tool for the characterisation and potential treatment guidance of arrhythmias.
Collapse
Affiliation(s)
- Clara Herrero Martin
- Department of Bioengineering, Imperial College London, London, United Kingdom
- ITACA Institute, Universitat Politècnica de València, Valencia, Spain
| | - Alon Oved
- Department of Computing, Imperial College London, London, United Kingdom
| | - Rasheda A. Chowdhury
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Elisabeth Ullmann
- Department of Mathematics, Technical University of Munich, Munich, Germany
| | - Nicholas S. Peters
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Anil A. Bharath
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | - Marta Varela
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| |
Collapse
|
26
|
Ultrafast four-dimensional imaging of cardiac mechanical wave propagation with sparse optoacoustic sensing. Proc Natl Acad Sci U S A 2021; 118:2103979118. [PMID: 34732573 DOI: 10.1073/pnas.2103979118] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/21/2021] [Indexed: 12/25/2022] Open
Abstract
Propagation of electromechanical waves in excitable heart muscles follows complex spatiotemporal patterns holding the key to understanding life-threatening arrhythmias and other cardiac conditions. Accurate volumetric mapping of cardiac wave propagation is currently hampered by fast heart motion, particularly in small model organisms. Here we demonstrate that ultrafast four-dimensional imaging of cardiac mechanical wave propagation in entire beating murine heart can be accomplished by sparse optoacoustic sensing with high contrast, ∼115-µm spatial and submillisecond temporal resolution. We extract accurate dispersion and phase velocity maps of the cardiac waves and reveal vortex-like patterns associated with mechanical phase singularities that occur during arrhythmic events induced via burst ventricular electric stimulation. The newly introduced cardiac mapping approach is a bold step toward deciphering the complex mechanisms underlying cardiac arrhythmias and enabling precise therapeutic interventions.
Collapse
|
27
|
Knighton NJ, Cottle BK, Tiwari S, Mondal A, Kaza AK, Sachse FB, Hitchcock RW. Toward cardiac tissue characterization using machine learning and light-scattering spectroscopy. JOURNAL OF BIOMEDICAL OPTICS 2021; 26:JBO-200330RR. [PMID: 34729970 PMCID: PMC8562351 DOI: 10.1117/1.jbo.26.11.116001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 10/12/2021] [Indexed: 06/13/2023]
Abstract
SIGNIFICANCE The non-destructive characterization of cardiac tissue composition provides essential information for both planning and evaluating the effectiveness of surgical interventions such as ablative procedures. Although several methods of tissue characterization, such as optical coherence tomography and fiber-optic confocal microscopy, show promise, many barriers exist that reduce effectiveness or prevent adoption, such as time delays in analysis, prohibitive costs, and limited scope of application. Developing a rapid, low-cost non-destructive means of characterizing cardiac tissue could improve planning, implementation, and evaluation of cardiac surgical procedures. AIM To determine whether a new light-scattering spectroscopy (LSS) system that analyzes spectra via neural networks is capable of predicting the nuclear densities (NDs) of ventricular tissues. APPROACH We developed an LSS system with a fiber-optics probe and applied it for measurements on cardiac tissues from an ovine model. We quantified the ND in the cardiac tissues using fluorescent labeling, confocal microscopy, and image processing. Spectra acquired from the same cardiac tissues were analyzed with spectral clustering and convolutional neural networks (CNNs) to assess the feasibility of characterizing the ND of tissue via LSS. RESULTS Spectral clustering revealed distinct groups of spectra correlated to ranges of ND. CNNs classified three groups of spectra with low, medium, or high ND with an accuracy of 95.00 ± 11.77 % (mean and standard deviation). Our analyses revealed the sensitivity of the classification accuracy to wavelength range and subsampling of spectra. CONCLUSIONS LSS and machine learning are capable of assessing ND in cardiac tissues. We suggest that the approach is useful for the diagnosis of cardiac diseases associated with changes of ND, such as hypertrophy and fibrosis.
Collapse
Affiliation(s)
- Nathan J. Knighton
- University of Utah, Department of Biomedical Engineering, Salt Lake City, United States
- University of Utah, Nora Eccles Harrison Cardiovascular Research and Training Institute, Salt Lake City, United States
| | - Brian K. Cottle
- University of Utah, Department of Biomedical Engineering, Salt Lake City, United States
- University of Utah, Nora Eccles Harrison Cardiovascular Research and Training Institute, Salt Lake City, United States
| | - Sarthak Tiwari
- University of Utah, Department of Biomedical Engineering, Salt Lake City, United States
- University of Utah, Nora Eccles Harrison Cardiovascular Research and Training Institute, Salt Lake City, United States
| | - Abhijit Mondal
- Boston Children’s Hospital, Harvard Medical School, Department of Cardiac Surgery, Boston, United States
| | - Aditya K. Kaza
- Boston Children’s Hospital, Harvard Medical School, Department of Cardiac Surgery, Boston, United States
| | - Frank B. Sachse
- University of Utah, Department of Biomedical Engineering, Salt Lake City, United States
- University of Utah, Nora Eccles Harrison Cardiovascular Research and Training Institute, Salt Lake City, United States
| | - Robert W. Hitchcock
- University of Utah, Department of Biomedical Engineering, Salt Lake City, United States
| |
Collapse
|
28
|
Synchronized Cardiac Impulses Emerge From Heterogeneous Local Calcium Signals Within and Among Cells of Pacemaker Tissue. JACC Clin Electrophysiol 2021; 6:907-931. [PMID: 32819526 DOI: 10.1016/j.jacep.2020.06.022] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 06/19/2020] [Accepted: 06/24/2020] [Indexed: 12/11/2022]
Abstract
OBJECTIVES This study sought to identify subcellular Ca2+ signals within and among cells comprising the sinoatrial node (SAN) tissue. BACKGROUND The current paradigm of SAN impulse generation: 1) is that full-scale action potentials (APs) of a common frequency are initiated at 1 site and are conducted within the SAN along smooth isochrones; and 2) does not feature fine details of Ca2+ signaling present in isolated SAN cells, in which small subcellular, subthreshold local Ca2+ releases (LCRs) self-organize to generate cell-wide APs. METHODS Immunolabeling was combined with a novel technique to detect the occurrence of LCRs and AP-induced Ca2+ transients (APCTs) in individual pixels (chronopix) across the entire mouse SAN images. RESULTS At high magnification, Ca2+ signals appeared markedly heterogeneous in space, amplitude, frequency, and phase among cells comprising an HCN4+/CX43- cell meshwork. The signaling exhibited several distinguishable patterns of LCR/APCT interactions within and among cells. Rhythmic APCTs that were apparently conducted within the meshwork were transferred to a truly conducting HCN4-/CX43+ network of striated cells via narrow functional interfaces where different cell types intertwine, that is, the SAN anatomic/functional unit. At low magnification, the earliest APCT of each cycle occurred within a small area of the HCN4 meshwork, and subsequent APCT appearance throughout SAN pixels was discontinuous and asynchronous. CONCLUSIONS The study has discovered a novel, microscopic Ca2+ signaling paradigm of SAN operation that has escaped detection using low-resolution, macroscopic tissue isochrones employed in prior studies: synchronized APs emerge from heterogeneous subcellular subthreshold Ca2+ signals, resembling multiscale complex processes of impulse generation within clusters of neurons in neuronal networks.
Collapse
|
29
|
Ronzhina M, Stracina T, Lacinova L, Ondacova K, Pavlovicova M, Marsanova L, Smisek R, Janousek O, Fialova K, Kolarova J, Novakova M, Provaznik I. Di-4-ANEPPS Modulates Electrical Activity and Progress of Myocardial Ischemia in Rabbit Isolated Heart. Front Physiol 2021; 12:667065. [PMID: 34177617 PMCID: PMC8222999 DOI: 10.3389/fphys.2021.667065] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 04/12/2021] [Indexed: 11/16/2022] Open
Abstract
Aims Although voltage-sensitive dye di-4-ANEPPS is a common tool for mapping cardiac electrical activity, reported effects on electrophysiological parameters are rather. The main goals of the study were to reveal effects of the dye on rabbit isolated heart and to verify, whether rabbit isolated heart stained with di-4-ANEPPS is a suitable tool for myocardial ischemia investigation. Methods and Results Study involved experiments on stained (n = 9) and non-stained (n = 11) Langendorff perfused rabbit isolated hearts. Electrophysiological effects of the dye were evaluated by analysis of various electrogram (EG) parameters using common paired and unpaired statistical tests. It was shown that staining the hearts with di-4-ANEPPS leads to only short-term sporadic prolongation of impulse conduction through atria and atrioventricular node. On the other hand, significant irreversible slowing of heart rate and ventricular conduction were found in stained hearts as compared to controls. In patch clamp experiments, significant inhibition of sodium current density was observed in differentiated NG108-15 cells stained by the dye. Although no significant differences in mean number of ventricular premature beats were found between the stained and the non-stained hearts in ischemia as well as in reperfusion, all abovementioned results indicate increased arrhythmogenicity. In isolated hearts during ischemia, prominent ischemic patterns appeared in the stained hearts with 3–4 min delay as compared to the non-stained ones. Moreover, the ischemic changes did not achieve the same magnitude as in controls even after 10 min of ischemia. It resulted in poor performance of ischemia detection by proposed EG parameters, as was quantified by receiver operating characteristics analysis. Conclusion Our results demonstrate significant direct irreversible effect of di-4-ANEPPS on spontaneous heart rate and ventricular impulse conduction in rabbit isolated heart model. Particularly, this should be considered when di-4-ANEPPS is used in ischemia studies in rabbit. Delayed attenuated response of such hearts to ischemia might lead to misinterpretation of obtained results.
Collapse
Affiliation(s)
- Marina Ronzhina
- Department of Biomedical Engineering, Faculty of Electrical Engineering and Communication, Brno University of Technology, Brno, Czechia
| | - Tibor Stracina
- Department of Physiology, Faculty of Medicine, Masaryk University, Brno, Czechia
| | - Lubica Lacinova
- Centre of Biosciences, Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Katarina Ondacova
- Centre of Biosciences, Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Michaela Pavlovicova
- Centre of Biosciences, Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Lucie Marsanova
- Department of Biomedical Engineering, Faculty of Electrical Engineering and Communication, Brno University of Technology, Brno, Czechia
| | - Radovan Smisek
- Department of Biomedical Engineering, Faculty of Electrical Engineering and Communication, Brno University of Technology, Brno, Czechia
| | - Oto Janousek
- Department of Biomedical Engineering, Faculty of Electrical Engineering and Communication, Brno University of Technology, Brno, Czechia
| | - Katerina Fialova
- Department of Physiology, Faculty of Medicine, Masaryk University, Brno, Czechia
| | - Jana Kolarova
- Department of Biomedical Engineering, Faculty of Electrical Engineering and Communication, Brno University of Technology, Brno, Czechia
| | - Marie Novakova
- Department of Physiology, Faculty of Medicine, Masaryk University, Brno, Czechia.,International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czechia
| | - Ivo Provaznik
- Department of Biomedical Engineering, Faculty of Electrical Engineering and Communication, Brno University of Technology, Brno, Czechia
| |
Collapse
|
30
|
Kowalewski C. Mapping atrial fibrillation : An overview of potential mechanisms underlying atrial fibrillation. Herz 2021; 46:305-311. [PMID: 34104977 DOI: 10.1007/s00059-021-05045-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/29/2021] [Indexed: 11/24/2022]
Abstract
Mechanisms sustaining atrial fibrillation are yet to be clarified. This article focuses on milestones in the theory of atrial fibrillation and addresses the different leading hypotheses concerning atrial fibrillation mechanisms. We start off with electric potential originating from the pulmonary vein, which triggers atrial fibrillation, discuss classic activation mapping and phase mapping as well as computer models, which have contributed to the our understanding of atrial fibrillation, and end with new mapping methods and studies highlighting the advantages and disadvantages of current mechanistic hypotheses. The technical evolution of mapping atrial fibrillation has led to new insights into the potential mechanisms underlying atrial fibrillation. A comparison between methods is essential for understanding the advantages and disadvantages of each method when mapping atrial fibrillation. Ultimately, the combination of several methods might shed light on the underlying mechanisms of atrial fibrillation and lead to a better understanding of atrial fibrillation and subsequently improve treatment of this condition.
Collapse
|
31
|
Tomek J, Wang ZJ, Burton RAB, Herring N, Bub G. COSMAS: a lightweight toolbox for cardiac optical mapping analysis. Sci Rep 2021; 11:9147. [PMID: 33911090 PMCID: PMC8080775 DOI: 10.1038/s41598-021-87402-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 03/22/2021] [Indexed: 12/14/2022] Open
Abstract
Optical mapping is widely used in experimental cardiology, as it allows visualization of cardiac membrane potential and calcium transients. However, optical mapping measurements from a single heart or cell culture can produce several gigabytes of data, warranting automated computer analysis. Here we present COSMAS, a software toolkit for automated analysis of optical mapping recordings in cardiac preparations. COSMAS generates activation and conduction velocity maps, as well as visualizations of action potential and calcium transient duration, S1-S2 protocol analysis, and alternans mapping. The software is built around our recent 'comb' algorithm for segmentation of action potentials and calcium transients, offering excellent performance and high resistance to noise. A core feature of our software is that it is based on scripting as opposed to relying on a graphical user interface for user input. The central role of scripts in the analysis pipeline enables batch processing and promotes reproducibility and transparency in the interpretation of large cardiac data sets. Finally, the code is designed to be easily extended, allowing researchers to add functionality if needed. COSMAS is provided in two languages, Matlab and Python, and is distributed with a user guide and sample scripts, so that accessibility to researchers is maximized.
Collapse
Affiliation(s)
- Jakub Tomek
- Department of Physiology, Anatomy, and Genetics, University of Oxford, Oxford, UK. .,Department of Computer Science, University of Oxford, Oxford, UK.
| | | | | | - Neil Herring
- Department of Physiology, Anatomy, and Genetics, University of Oxford, Oxford, UK
| | - Gil Bub
- Department of Physiology, McGill University, Montréal, Canada
| |
Collapse
|
32
|
Chowdhury RA, Debney MT, Protti A, Handa BS, Patel KHK, Lyon AR, Shah AM, Ng FS, Peters NS. Rotigaptide Infusion for the First 7 Days After Myocardial Infarction-Reperfusion Reduced Late Complexity of Myocardial Architecture of the Healing Border-Zone and Arrhythmia Inducibility. J Am Heart Assoc 2021; 10:e020006. [PMID: 33870715 PMCID: PMC8200720 DOI: 10.1161/jaha.120.020006] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Background Survivors of myocardial infarction are at increased risk of late ventricular arrhythmias, with infarct size and scar heterogeneity being key determinants of arrhythmic risk. Gap junctions facilitate the passage of small ions and morphogenic cell signaling between myocytes. We hypothesized that gap junctions enhancement during infarction–reperfusion modulates structural and electrophysiological remodeling and reduces late arrhythmogenesis. Methods and Results Infarction–reperfusion surgery was carried out in male Sprague‐Dawley rats followed by 7 days of rotigaptide or saline administration. The in vivo and ex vivo arrhythmogenicity was characterized by programmed electrical stimulation 3 weeks later, followed by diffusion‐weighted magnetic resonance imaging and Masson's trichrome histology. Three weeks after 7‐day postinfarction administration of rotigaptide, ventricular tachycardia/ventricular fibrillation was induced on programmed electrical stimulation in 20% and 53% of rats, respectively (rotigaptide versus control), resulting in reduction of arrhythmia score (3.2 versus 1.4, P=0.018), associated with the reduced magnetic resonance imaging parameters fractional anisotropy (fractional anisotropy: −5% versus −15%; P=0.062) and mean diffusivity (mean diffusivity: 2% versus 6%, P=0.042), and remodeling of the 3‐dimensional laminar structure of the infarct border zone with reduction of the mean (16° versus 19°, P=0.013) and the dispersion (9° versus 12°, P=0.015) of the myofiber transverse angle. There was no change in ECG features, spontaneous arrhythmias, or mortality. Conclusions Enhancement of gap junctions function by rotigaptide administered during the early healing phase in reperfused infarction reduces later complexity of infarct scar morphology and programmed electrical stimulation–induced arrhythmias, and merits further exploration as a feasible and practicable intervention in the acute myocardial infarction management to reduce late arrhythmic risk.
Collapse
Affiliation(s)
- Rasheda A Chowdhury
- National Heart & Lung Institute and ElectroCardioMaths Programme of the Imperial Centre for Cardiac EngineeringImperial College London London United Kingdom
| | - Michael T Debney
- National Heart & Lung Institute and ElectroCardioMaths Programme of the Imperial Centre for Cardiac EngineeringImperial College London London United Kingdom
| | - Andrea Protti
- King's British Heart Foundation Centre School of Cardiovascular Medicine and Sciences Kings College London London United Kingdom
| | - Balvinder S Handa
- National Heart & Lung Institute and ElectroCardioMaths Programme of the Imperial Centre for Cardiac EngineeringImperial College London London United Kingdom
| | - Kiran H K Patel
- National Heart & Lung Institute and ElectroCardioMaths Programme of the Imperial Centre for Cardiac EngineeringImperial College London London United Kingdom
| | - Alexander R Lyon
- National Heart & Lung Institute and ElectroCardioMaths Programme of the Imperial Centre for Cardiac EngineeringImperial College London London United Kingdom
| | - Ajay M Shah
- King's British Heart Foundation Centre School of Cardiovascular Medicine and Sciences Kings College London London United Kingdom
| | - Fu Siong Ng
- National Heart & Lung Institute and ElectroCardioMaths Programme of the Imperial Centre for Cardiac EngineeringImperial College London London United Kingdom
| | - Nicholas S Peters
- National Heart & Lung Institute and ElectroCardioMaths Programme of the Imperial Centre for Cardiac EngineeringImperial College London London United Kingdom
| |
Collapse
|
33
|
Tadevosyan K, Iglesias-García O, Mazo MM, Prósper F, Raya A. Engineering and Assessing Cardiac Tissue Complexity. Int J Mol Sci 2021; 22:ijms22031479. [PMID: 33540699 PMCID: PMC7867236 DOI: 10.3390/ijms22031479] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 01/28/2021] [Accepted: 01/28/2021] [Indexed: 01/14/2023] Open
Abstract
Cardiac tissue engineering is very much in a current focus of regenerative medicine research as it represents a promising strategy for cardiac disease modelling, cardiotoxicity testing and cardiovascular repair. Advances in this field over the last two decades have enabled the generation of human engineered cardiac tissue constructs with progressively increased functional capabilities. However, reproducing tissue-like properties is still a pending issue, as constructs generated to date remain immature relative to native adult heart. Moreover, there is a high degree of heterogeneity in the methodologies used to assess the functionality and cardiac maturation state of engineered cardiac tissue constructs, which further complicates the comparison of constructs generated in different ways. Here, we present an overview of the general approaches developed to generate functional cardiac tissues, discussing the different cell sources, biomaterials, and types of engineering strategies utilized to date. Moreover, we discuss the main functional assays used to evaluate the cardiac maturation state of the constructs, both at the cellular and the tissue levels. We trust that researchers interested in developing engineered cardiac tissue constructs will find the information reviewed here useful. Furthermore, we believe that providing a unified framework for comparison will further the development of human engineered cardiac tissue constructs displaying the specific properties best suited for each particular application.
Collapse
Affiliation(s)
- Karine Tadevosyan
- Regenerative Medicine Program, Bellvitge Institute for Biomedical Research (IDIBELL) and Program for Clinical Translation of Regenerative Medicine in Catalonia (P-CMRC), 08908 L’Hospitalet del Llobregat, Spain;
- Center for Networked Biomedical Research on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), 28029 Madrid, Spain
| | - Olalla Iglesias-García
- Regenerative Medicine Program, Bellvitge Institute for Biomedical Research (IDIBELL) and Program for Clinical Translation of Regenerative Medicine in Catalonia (P-CMRC), 08908 L’Hospitalet del Llobregat, Spain;
- Center for Networked Biomedical Research on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), 28029 Madrid, Spain
- Regenerative Medicine Program, Cima Universidad de Navarra, Foundation for Applied Medical Research, 31008 Pamplona, Spain; (M.M.M.); (F.P.)
- IdiSNA, Navarra Institute for Health Research, 31008 Pamplona, Spain
- Correspondence: (O.I.-G.); (A.R.)
| | - Manuel M. Mazo
- Regenerative Medicine Program, Cima Universidad de Navarra, Foundation for Applied Medical Research, 31008 Pamplona, Spain; (M.M.M.); (F.P.)
- IdiSNA, Navarra Institute for Health Research, 31008 Pamplona, Spain
- Hematology and Cell Therapy Area, Clínica Universidad de Navarra, 31008 Pamplona, Spain
| | - Felipe Prósper
- Regenerative Medicine Program, Cima Universidad de Navarra, Foundation for Applied Medical Research, 31008 Pamplona, Spain; (M.M.M.); (F.P.)
- IdiSNA, Navarra Institute for Health Research, 31008 Pamplona, Spain
- Hematology and Cell Therapy Area, Clínica Universidad de Navarra, 31008 Pamplona, Spain
- Center for Networked Biomedical Research on Cancer (CIBERONC), 28029 Madrid, Spain
| | - Angel Raya
- Regenerative Medicine Program, Bellvitge Institute for Biomedical Research (IDIBELL) and Program for Clinical Translation of Regenerative Medicine in Catalonia (P-CMRC), 08908 L’Hospitalet del Llobregat, Spain;
- Center for Networked Biomedical Research on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), 28029 Madrid, Spain
- Catalan Institution for Research and Advanced Studies (ICREA), 08010 Barcelona, Spain
- Correspondence: (O.I.-G.); (A.R.)
| |
Collapse
|
34
|
Li H, Liu H, Sun M, Huang Y, Xu L. 3D Interfacing between Soft Electronic Tools and Complex Biological Tissues. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2004425. [PMID: 33283351 DOI: 10.1002/adma.202004425] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 08/08/2020] [Indexed: 06/12/2023]
Abstract
Recent developments in soft functional materials have created opportunities for building bioelectronic devices with tissue-like mechanical properties. Their integration with the human body could enable advanced sensing and stimulation for medical diagnosis and therapies. However, most of the available soft electronics are constructed as planar sheets, which are difficult to interface with the target organs and tissues that have complex 3D structures. Here, the recent approaches are highlighted to building 3D interfaces between soft electronic tools and complex biological organs and tissues. Examples involve mesh devices for conformal contact, imaging-guided fabrication of organ-specific electronics, miniaturized probes for neurointerfaces, instrumented scaffold for tissue engineering, and many other soft 3D systems. They represent diverse routes for reconciling the interfacial mismatches between electronic tools and biological tissues. The remaining challenges include device scaling to approach the complexity of target organs, biological data acquisition and processing, 3D manufacturing techniques, etc., providing a range of opportunities for scientific research and technological innovation.
Collapse
Affiliation(s)
- Hegeng Li
- Department of Mechanical Engineering, The University of Hong Kong, Hong Kong SAR, 999077, China
- State Key Laboratory of Digital Manufacturing Equipment and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Hongzhen Liu
- Department of Mechanical Engineering, The University of Hong Kong, Hong Kong SAR, 999077, China
| | - Mingze Sun
- Department of Mechanical Engineering, The University of Hong Kong, Hong Kong SAR, 999077, China
| | - YongAn Huang
- State Key Laboratory of Digital Manufacturing Equipment and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Lizhi Xu
- Department of Mechanical Engineering, The University of Hong Kong, Hong Kong SAR, 999077, China
| |
Collapse
|
35
|
Machikhin AS, Burlakov AB, Volkov MV, Khokhlov DD. Imaging photoplethysmography and videocapillaroscopy enable noninvasive study of zebrafish cardiovascular system functioning. JOURNAL OF BIOPHOTONICS 2020; 13:e202000061. [PMID: 32306547 DOI: 10.1002/jbio.202000061] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 04/02/2020] [Accepted: 04/15/2020] [Indexed: 06/11/2023]
Abstract
We report on the noninvasive method for in vivo study of fish's cardiovascular system, that is, the heart and the structure of vessels that carry blood throughout the body. The proposed approach is based on combined photoplethysmographic and videocapillaroscopic microscopic imaging and enables noncontact two-dimensional mapping of blood volume changes. We demonstrate that the obtained data allows precise measurements of heartbeat, blood flow velocity and other important parameters (see Videos S1 and S2). To validate the developed image processing technique, we have carried out multiple experiments on zebrafish-a well-proven informative model organism widely used to understand cardiac development. The proposed approach may be effective for the study of cardiovascular system formation and functioning as well as the impact of various influencing factors on them.
Collapse
Affiliation(s)
- Alexander S Machikhin
- Laboratory of Acoustooptical Spectroscopy, Scientific and Technological Center of Unique Instrumentation, Russian Academy of Sciences, Moscow, Russia
| | - Alexander B Burlakov
- Department of Ichthyology, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Mikhail V Volkov
- Department of Applied Optics, University ITMO, Saint Petersburg, Russia
| | - Demid D Khokhlov
- Laboratory of Acoustooptical Spectroscopy, Scientific and Technological Center of Unique Instrumentation, Russian Academy of Sciences, Moscow, Russia
| |
Collapse
|
36
|
Intrinsically stretchable electrode array enabled in vivo electrophysiological mapping of atrial fibrillation at cellular resolution. Proc Natl Acad Sci U S A 2020; 117:14769-14778. [PMID: 32541030 DOI: 10.1073/pnas.2000207117] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Electrophysiological mapping of chronic atrial fibrillation (AF) at high throughput and high resolution is critical for understanding its underlying mechanism and guiding definitive treatment such as cardiac ablation, but current electrophysiological tools are limited by either low spatial resolution or electromechanical uncoupling of the beating heart. To overcome this limitation, we herein introduce a scalable method for fabricating a tissue-like, high-density, fully elastic electrode (elastrode) array capable of achieving real-time, stable, cellular level-resolution electrophysiological mapping in vivo. Testing with acute rabbit and porcine models, the device is proven to have robust and intimate tissue coupling while maintaining its chemical, mechanical, and electrical properties during the cardiac cycle. The elastrode array records epicardial atrial signals with comparable efficacy to currently available endocardial-mapping techniques but with 2 times higher atrial-to-ventricular signal ratio and >100 times higher spatial resolution and can reliably identify electrical local heterogeneity within an area of simultaneously identified rotor-like electrical patterns in a porcine model of chronic AF.
Collapse
|
37
|
Hoffman MJ, Cherry EM. Sensitivity of a data-assimilation system for reconstructing three-dimensional cardiac electrical dynamics. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2020; 378:20190388. [PMID: 32448069 PMCID: PMC7287341 DOI: 10.1098/rsta.2019.0388] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 02/25/2020] [Indexed: 05/21/2023]
Abstract
Modelling of cardiac electrical behaviour has led to important mechanistic insights, but important challenges, including uncertainty in model formulations and parameter values, make it difficult to obtain quantitatively accurate results. An alternative approach is combining models with observations from experiments to produce a data-informed reconstruction of system states over time. Here, we extend our earlier data-assimilation studies using an ensemble Kalman filter to reconstruct a three-dimensional time series of states with complex spatio-temporal dynamics using only surface observations of voltage. We consider the effects of several algorithmic and model parameters on the accuracy of reconstructions of known scroll-wave truth states using synthetic observations. In particular, we study the algorithm's sensitivity to parameters governing different parts of the process and its robustness to several model-error conditions. We find that the algorithm can achieve an acceptable level of error in many cases, with the weakest performance occurring for model-error cases and more extreme parameter regimes with more complex dynamics. Analysis of the poorest-performing cases indicates an initial decrease in error followed by an increase when the ensemble spread is reduced. Our results suggest avenues for further improvement through increasing ensemble spread by incorporating additive inflation or using a parameter or multi-model ensemble. This article is part of the theme issue 'Uncertainty quantification in cardiac and cardiovascular modelling and simulation'.
Collapse
Affiliation(s)
- Matthew J. Hoffman
- School of Mathematical Sciences, Rochester Institute of Technology, Rochester, NY 14623, USA
| | | |
Collapse
|
38
|
Optical mapping of the pig heart in situ under artificial blood circulation. Sci Rep 2020; 10:8548. [PMID: 32444634 PMCID: PMC7244500 DOI: 10.1038/s41598-020-65464-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 04/22/2020] [Indexed: 12/05/2022] Open
Abstract
The emergence of optical imaging has revolutionized the investigation of cardiac electrical activity and associated disorders in various cardiac pathologies. The electrical signals of the heart and the propagation pathways are crucial for elucidating the mechanisms of various cardiac pathological conditions, including arrhythmia. The synthesis of near-infrared voltage-sensitive dyes and the voltage sensitivity of the FDA-approved dye Cardiogreen have increased the importance of optical mapping (OM) as a prospective tool in clinical practice. We aimed to develop a method for the high-spatiotemporal-resolution OM of the large animal hearts in situ using di-4-ANBDQBS and Cardiogreen under patho/physiological conditions. OM was adapted to monitor cardiac electrical behaviour in an open-chest pig heart model with physiological or artificial blood circulation. We detail the methods and display the OM data obtained using di-4-ANBDQBS and Cardiogreen. Activation time, action potential duration, repolarization time and conduction velocity maps were constructed. The technique was applied to track cardiac electrical activity during regional ischaemia and arrhythmia. Our study is the first to apply high-spatiotemporal-resolution OM in the pig heart in situ to record cardiac electrical activity qualitatively under artificial blood perfusion. The use of an FDA-approved voltage-sensitive dye and artificial blood perfusion in a swine model, which is generally accepted as a valuable pre-clinical model, demonstrates the promise of OM for clinical application.
Collapse
|
39
|
Benson AP, Stevenson-Cocks HJ, Whittaker DG, White E, Colman MA. Multi-scale approaches for the simulation of cardiac electrophysiology: II - Tissue-level structure and function. Methods 2020; 185:60-81. [PMID: 31988002 DOI: 10.1016/j.ymeth.2020.01.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 11/15/2019] [Accepted: 01/14/2020] [Indexed: 02/06/2023] Open
Abstract
Computational models of the heart, from cell-level models, through one-, two- and three-dimensional tissue-level simplifications, to biophysically-detailed three-dimensional models of the ventricles, atria or whole heart, allow the simulation of excitation and propagation of this excitation, and have provided remarkable insight into the normal and pathological functioning of the heart. In this article we present equations for modelling cellular excitation (i.e. the cell action potential) from both a phenomenological and a biophysical perspective. Hodgkin-Huxley formalism is discussed, along with the current generation of biophysically-detailed cardiac cell models. Alternative Markovian formulations for modelling ionic currents are also presented. Equations describing propagation of this cellular excitation, through one-, two- and three-dimensional idealised or realistic tissues, are then presented. For all types of model, from cell to tissue, methods for discretisation and integration of the underlying equations are discussed. The article finishes with a discussion of two tissue-level experimental imaging techniques - diffusion tensor magnetic resonance imaging and optical imaging - that can be used to provide data for parameterisation and validation of cell- and tissue-level cardiac models.
Collapse
Affiliation(s)
- Alan P Benson
- School of Biomedical Sciences University of Leeds, Leeds LS2 9JT, UK.
| | | | - Dominic G Whittaker
- School of Biomedical Sciences University of Leeds, Leeds LS2 9JT, UK; School of Mathematical Sciences, University of Nottingham, Nottingham NG7 2RD, UK
| | - Ed White
- School of Biomedical Sciences University of Leeds, Leeds LS2 9JT, UK
| | - Michael A Colman
- School of Biomedical Sciences University of Leeds, Leeds LS2 9JT, UK
| |
Collapse
|
40
|
Swift LM, Jaimes R, McCullough D, Burke M, Reilly M, Maeda T, Zhang H, Ishibashi N, Rogers JM, Posnack NG. Optocardiography and Electrophysiology Studies of Ex Vivo Langendorff-perfused Hearts. J Vis Exp 2019. [PMID: 31762469 DOI: 10.3791/60472] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Small animal models are most commonly used in cardiovascular research due to the availability of genetically modified species and lower cost compared to larger animals. Yet, larger mammals are better suited for translational research questions related to normal cardiac physiology, pathophysiology, and preclinical testing of therapeutic agents. To overcome the technical barriers associated with employing a larger animal model in cardiac research, we describe an approach to measure physiological parameters in an isolated, Langendorff-perfused piglet heart. This approach combines two powerful experimental tools to evaluate the state of the heart: electrophysiology (EP) study and simultaneous optical mapping of transmembrane voltage and intracellular calcium using parameter sensitive dyes (RH237, Rhod2-AM). The described methodologies are well suited for translational studies investigating the cardiac conduction system, alterations in action potential morphology, calcium handling, excitation-contraction coupling and the incidence of cardiac alternans or arrhythmias.
Collapse
Affiliation(s)
- Luther M Swift
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital; Children's National Heart Institute, Children's National Hospital
| | - Rafael Jaimes
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital; Children's National Heart Institute, Children's National Hospital
| | - Damon McCullough
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital; Children's National Heart Institute, Children's National Hospital
| | - Morgan Burke
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital; Children's National Heart Institute, Children's National Hospital
| | - Marissa Reilly
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital; Children's National Heart Institute, Children's National Hospital
| | - Takuya Maeda
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital; Children's National Heart Institute, Children's National Hospital; Center for Neuroscience Research, Children's National Hospital
| | - Hanyu Zhang
- Department of Biomedical Engineering, School of Engineering, University of Alabama at Birmingham
| | - Nobuyuki Ishibashi
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital; Children's National Heart Institute, Children's National Hospital; Center for Neuroscience Research, Children's National Hospital
| | - Jack M Rogers
- Department of Biomedical Engineering, School of Engineering, University of Alabama at Birmingham
| | - Nikki Gillum Posnack
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital; Children's National Heart Institute, Children's National Hospital; Department of Pediatrics, Department of Pharmacology & Physiology, School of Medicine and Health Sciences, George Washington University;
| |
Collapse
|
41
|
Jaimes R, McCullough D, Siegel B, Swift L, Hiebert J, Mclnerney D, Posnack NG. Lights, camera, path splitter: a new approach for truly simultaneous dual optical mapping of the heart with a single camera. BMC Biomed Eng 2019; 1. [PMID: 31768502 PMCID: PMC6876868 DOI: 10.1186/s42490-019-0024-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Background Optical mapping of transmembrane voltage and intracellular calcium is a powerful tool for investigating cardiac physiology and pathophysiology. However, simultaneous dual mapping of two fluorescent probes remains technically challenging. We introduce a novel, easy-to-use approach that requires a path splitter, single camera and excitation light to simultaneously acquire voltage and calcium signals from whole heart preparations, which can be applied to other physiological models – including neurons and isolated cardiomyocytes. Results Complementary probes were selected that could be excited with a single wavelength light source. Langendorff-perfused hearts (rat, swine) were stained and imaged using a sCMOS camera outfitted with an optical path splitter to simultaneously acquire two emission fields at high spatial and temporal resolution. Voltage (RH237) and calcium (Rhod2) signals were acquired concurrently on a single sensor, resulting in two 384 × 256 images at 814 frames per second. At this frame rate, the signal-to-noise ratio was 47 (RH237) and 85 (Rhod2). Imaging experiments were performed on small rodent hearts, as well as larger pig hearts with sufficient optical signals. In separate experiments, each dye was used independently to assess crosstalk and demonstrate signal specificity. Additionally, the effect of ryanodine on myocardial calcium transients was validated – with no measurable effect on the amplitude of optical action potentials. To demonstrate spatial resolution, ventricular tachycardia was induced –resulting in the novel finding that spatially discordant calcium alternans can be present in different regions of the heart, even when electrical alternans remain concordant. The described system excels in providing a wide field of view and high spatiotemporal resolution for a variety of cardiac preparations. Conclusions We report the first multiparametric mapping system that simultaneously acquires calcium and voltage signals from cardiac preparations, using a path splitter, single camera and excitation light. This approach eliminates the need for multiple cameras, excitation light patterning or frame interleaving. These features can aid in the adoption of dual mapping technology by the broader cardiovascular research community, and decrease the barrier of entry into panoramic heart imaging, as it reduces the number of required cameras. Electronic supplementary material The online version of this article (10.1186/s42490-019-0024-x) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Rafael Jaimes
- Sheikh Zayed Institute for Pediatric and Surgical Innovation: Children's National Health System, 6th floor, M7708, 111 Michigan Avenue NW, Washington, DC 20010, USA.,Children's National Heart Institute: Children's National Health System, 111 Michigan Avenue NW, Washington, DC 20010, USA
| | - Damon McCullough
- Sheikh Zayed Institute for Pediatric and Surgical Innovation: Children's National Health System, 6th floor, M7708, 111 Michigan Avenue NW, Washington, DC 20010, USA
| | - Bryan Siegel
- Children's National Heart Institute: Children's National Health System, 111 Michigan Avenue NW, Washington, DC 20010, USA
| | - Luther Swift
- Sheikh Zayed Institute for Pediatric and Surgical Innovation: Children's National Health System, 6th floor, M7708, 111 Michigan Avenue NW, Washington, DC 20010, USA.,Children's National Heart Institute: Children's National Health System, 111 Michigan Avenue NW, Washington, DC 20010, USA
| | - James Hiebert
- Sheikh Zayed Institute for Pediatric and Surgical Innovation: Children's National Health System, 6th floor, M7708, 111 Michigan Avenue NW, Washington, DC 20010, USA
| | - Daniel Mclnerney
- Sheikh Zayed Institute for Pediatric and Surgical Innovation: Children's National Health System, 6th floor, M7708, 111 Michigan Avenue NW, Washington, DC 20010, USA
| | - Nikki Gillum Posnack
- Sheikh Zayed Institute for Pediatric and Surgical Innovation: Children's National Health System, 6th floor, M7708, 111 Michigan Avenue NW, Washington, DC 20010, USA.,Children's National Heart Institute: Children's National Health System, 111 Michigan Avenue NW, Washington, DC 20010, USA.,Department of Pediatrics, Department of Pharmacology & Physiology, School of Medicine and Health Sciences: George Washington University, 2300 I Street NW, Washington, DC 20037, USA
| |
Collapse
|
42
|
Eisner S, Fenton FH, Uzelac I. Baseline Wandering Removal in Optical Mapping Measurements With PID Control in Phase Space. COMPUTING IN CARDIOLOGY 2019; 46. [PMID: 34765680 DOI: 10.22489/cinc.2019.442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Optical imaging methods on ex-vivo hearts have had large impact in furthering our understanding of cardiac electrophysiology. One common problem in this method is a baseline wandering of the fluorescence signals over time, caused by dye photo-bleaching, small variation of the excitation light source, or other similar artifacts. Due to its relative magnitude, the removal of baseline wandering can be a nontrivial task and has major implications for analyzing important physiological dynamics such as traveling waves and alternans. Here we present a computational technique for the removal of such baseline wandering based on Proportional-Integral-Derivative (PID) closed loop feedback. The PID method applied a continuous control stimulus to the input Vm based on an error value which is defined by Euclidean distance from a pre-computed setpoint in phase space. We quantify and validate the PID control method by adding a linear combination of arbitrary sinusoidal drift, of frequency less than the signal pacing frequency, to the system signal Vm. The PID control loop effectively removed the baseline wandering with minimal degradation to the input Vm, and thus provides a viable tool for baseline wandering removal when implemented in an appropriate phase space. The computational simplicity of the method also lends itself to implementation in embedded systems, such as Arduinos and Raspberry-Pis.
Collapse
|
43
|
Pereira RHA, Prado AR, Caro LFCD, Zanardo TÉC, Alencar AP, Nogueira BV. A non-linear mathematical model using optical sensor to predict heart decellularization efficacy. Sci Rep 2019; 9:12211. [PMID: 31434981 PMCID: PMC6704168 DOI: 10.1038/s41598-019-48659-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 08/07/2019] [Indexed: 12/14/2022] Open
Abstract
One of the main problems of the decellularization technique is the subjectivity of the final evaluation of its efficacy in individual organs. This problem can result in restricted cell repopulation reproducibility and worse responses to transplant tissues. Our proposal is to analyze the optical profiles produced by hearts during perfusion decellularization, as an additional method for evaluating the decellularization process of each individual organ. An apparatus comprised of a structured LED source and photo detector on an adjustable base was developed to capture the relationship between transmitted light during the perfusion of murine hearts, and residual DNA content. Voltage-time graphic records were used to identify a nonlinear mathematical model to discriminate between decellularizations with remaining DNA above (Incomplete Decellularization) and below (Complete Decellularization) the standardized limits. The results indicate that temporal optical evaluation of the process enables inefficient cell removal to be predicted in the initial stages, regardless of the apparent transparency of the organ. Our open system also creates new possibilities to add distinct photo detectors, such as for specific wavelengths, image acquisition, and physical-chemical evaluation of the scaffold, in order to collect different kinds of information, from dozens of studies. These data, when compiled and submitted to machine learning techniques, have the potential to initiate an exponential advance in tissue bioengineering research.
Collapse
Affiliation(s)
- Rayssa Helena Arruda Pereira
- Carlos Alberto Redins Cell Ultrastructure Laboratory (LUCCAR) and Tissue Engineering Core, Department of Morphology - Health Sciences Center, Federal University of Espírito Santo (UFES), Vitória, ES, Brazil
- Biotechnology Graduate Program - Rede Nordeste de Biotecnologia (RENORBIO), Vitória, ES, Brazil
| | - Adilson Ribeiro Prado
- Department of Control Engineering and Automation, Federal Institute of Espírito Santo, Serra, ES, Brazil
| | | | - Tadeu Ériton Caliman Zanardo
- Carlos Alberto Redins Cell Ultrastructure Laboratory (LUCCAR) and Tissue Engineering Core, Department of Morphology - Health Sciences Center, Federal University of Espírito Santo (UFES), Vitória, ES, Brazil
- Biotechnology Graduate Program - Rede Nordeste de Biotecnologia (RENORBIO), Vitória, ES, Brazil
| | - Airlane Pereira Alencar
- Department of Statistic, Institute of Mathematics and Statics, São Paulo University, São Paulo, SP, Brazil
| | - Breno Valentim Nogueira
- Carlos Alberto Redins Cell Ultrastructure Laboratory (LUCCAR) and Tissue Engineering Core, Department of Morphology - Health Sciences Center, Federal University of Espírito Santo (UFES), Vitória, ES, Brazil.
- Biotechnology Graduate Program - Rede Nordeste de Biotecnologia (RENORBIO), Vitória, ES, Brazil.
| |
Collapse
|
44
|
Paradoxical Effects of Sodium-Calcium Exchanger Inhibition on Torsade de Pointes and Early Afterdepolarization in a Heart Failure Rabbit Model. J Cardiovasc Pharmacol 2019; 72:97-105. [PMID: 29738372 DOI: 10.1097/fjc.0000000000000598] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Calcium homeostasis plays an important role in development of early afterdepolarizations (EADs) and torsade de pointes (TdP). The role of sodium-calcium exchanger (NCX) inhibition in genesis of secondary Ca rise and EAD-TdP is still debated. Dual voltage and intracellular Ca optical mapping were conducted in 6 control and 9 failing rabbit hearts. After baseline electrophysiological and optical mapping studies, E4031 was given to simulate long QT syndrome. ORM-10103 was then administrated to examine the electrophysiological effects on EAD-TdP development. E4031 enhanced secondary Ca rise, EADs development, and TdP inducibility in both control and failing hearts. The results showed that ORM-10103 reduced premature ventricular beats but was unable to suppress the inducibility of TdP or EADs. The electrophysiological effects of ORM-10103 included prolongation of action potential duration (APD) and increased APD heterogeneity in failing hearts. ORM-10103 had a neutral effect on the amplitude of secondary Cai rise in control and heart failure groups. In this model, most EADs generated from long-short APD junction area. In conclusion, highly selective NCX inhibition with ORM-10103 reduced premature ventricular beat burden but was unable to suppress secondary Ca rise, EADs development, or inducibility of TdP. The possible electrophysiological mechanisms include APD prolongation and increased APD heterogeneity.
Collapse
|
45
|
Karlas A, Fasoula NA, Paul-Yuan K, Reber J, Kallmayer M, Bozhko D, Seeger M, Eckstein HH, Wildgruber M, Ntziachristos V. Cardiovascular optoacoustics: From mice to men - A review. PHOTOACOUSTICS 2019; 14:19-30. [PMID: 31024796 PMCID: PMC6476795 DOI: 10.1016/j.pacs.2019.03.001] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 03/18/2019] [Indexed: 05/04/2023]
Abstract
Imaging has become an indispensable tool in the research and clinical management of cardiovascular disease (CVD). An array of imaging technologies is considered for CVD diagnostics and therapeutic assessment, ranging from ultrasonography, X-ray computed tomography and magnetic resonance imaging to nuclear and optical imaging methods. Each method has different operational characteristics and assesses different aspects of CVD pathophysiology; nevertheless, more information is desirable for achieving a comprehensive view of the disease. Optoacoustic (photoacoustic) imaging is an emerging modality promising to offer novel information on CVD parameters by allowing high-resolution imaging of optical contrast several centimeters deep inside tissue. Implemented with illumination at several wavelengths, multi-spectral optoacoustic tomography (MSOT) in particular, is sensitive to oxygenated and deoxygenated hemoglobin, water and lipids allowing imaging of the vasculature, tissue oxygen saturation and metabolic or inflammatory parameters. Progress with fast-tuning lasers, parallel detection and advanced image reconstruction and data-processing algorithms have recently transformed optoacoustics from a laboratory tool to a promising modality for small animal and clinical imaging. We review progress with optoacoustic CVD imaging, highlight the research and diagnostic potential and current applications and discuss the advantages, limitations and possibilities for integration into clinical routine.
Collapse
Affiliation(s)
- Angelos Karlas
- Chair of Biological Imaging, TranslaTUM, Technical University of Munich, Munich, Germany
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
- Clinic for Vascular and Endovascular Surgery, University Hospital rechts der Isar, Munich, Germany
- German Center for Cardiovascular Research (DZHK), partner site Munich Heart Alliance, Munich, Germany
| | - Nikolina-Alexia Fasoula
- Chair of Biological Imaging, TranslaTUM, Technical University of Munich, Munich, Germany
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
| | - Korbinian Paul-Yuan
- Chair of Biological Imaging, TranslaTUM, Technical University of Munich, Munich, Germany
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
| | - Josefine Reber
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
| | - Michael Kallmayer
- Clinic for Vascular and Endovascular Surgery, University Hospital rechts der Isar, Munich, Germany
- German Center for Cardiovascular Research (DZHK), partner site Munich Heart Alliance, Munich, Germany
| | - Dmitry Bozhko
- Chair of Biological Imaging, TranslaTUM, Technical University of Munich, Munich, Germany
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
| | - Markus Seeger
- Chair of Biological Imaging, TranslaTUM, Technical University of Munich, Munich, Germany
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
| | - Hans-Henning Eckstein
- Clinic for Vascular and Endovascular Surgery, University Hospital rechts der Isar, Munich, Germany
- German Center for Cardiovascular Research (DZHK), partner site Munich Heart Alliance, Munich, Germany
| | - Moritz Wildgruber
- Institute for Diagnostic and Interventional Radiology, University Hospital rechts der Isar, Munich, Germany
- Institute for Clinical Radiology, University Hospital Muenster, Muenster, Germany
| | - Vasilis Ntziachristos
- Chair of Biological Imaging, TranslaTUM, Technical University of Munich, Munich, Germany
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
- German Center for Cardiovascular Research (DZHK), partner site Munich Heart Alliance, Munich, Germany
| |
Collapse
|
46
|
Hendon CP, Lye TH, Yao X, Gan Y, Marboe CC. Optical coherence tomography imaging of cardiac substrates. Quant Imaging Med Surg 2019; 9:882-904. [PMID: 31281782 PMCID: PMC6571187 DOI: 10.21037/qims.2019.05.09] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Accepted: 05/06/2019] [Indexed: 01/02/2023]
Abstract
Cardiovascular disease is the leading cause of morbidity and mortality in the United States. Knowledge of a patient's heart structure will help to plan procedures, potentially identifying arrhythmia substrates, critical structures to avoid, detect transplant rejection, and reduce ambiguity when interpreting electrograms and functional measurements. Similarly, basic research of numerous cardiac diseases would greatly benefit from structural imaging at cellular scale. For both applications imaging on the scale of a myocyte is needed, which is approximately 100 µm × 10 µm. The use of optical coherence tomography (OCT) as a tool for characterizing cardiac tissue structure and function has been growing in the past two decades. We briefly review OCT principles and highlight important considerations when imaging cardiac muscle. In particular, image penetration, tissue birefringence, and light absorption by blood during in vivo imaging are important factors when imaging the heart with OCT. Within the article, we highlight applications of cardiac OCT imaging including imaging heart tissue structure in small animal models, quantification of myofiber organization, monitoring of radiofrequency ablation (RFA) lesion formation, structure-function analysis enabled by functional extensions of OCT and multimodal analysis and characterizing important substrates within the human heart. The review concludes with a summary and future outlook of OCT imaging the heart, which is promising with progress in optical catheter development, functional extensions of OCT, and real time image processing to enable dynamic imaging and real time tracking during therapeutic procedures.
Collapse
Affiliation(s)
| | | | | | - Yu Gan
- Columbia University, New York, NY, USA
| | | |
Collapse
|
47
|
Tissue-Specific Optical Mapping Models of Swine Atria Informed by Optical Coherence Tomography. Biophys J 2019; 114:1477-1489. [PMID: 29590604 PMCID: PMC5883619 DOI: 10.1016/j.bpj.2018.01.035] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 01/12/2018] [Accepted: 01/30/2018] [Indexed: 11/21/2022] Open
Abstract
Computational models and experimental optical mapping of cardiac electrophysiology serve as powerful tools to investigate the underlying mechanisms of arrhythmias. Modeling can also aid the interpretation of optical mapping signals, which may have different characteristics with respect to the underlying electrophysiological signals they represent. However, despite the prevalence of atrial arrhythmias such as atrial fibrillation, models of optical electrical mapping incorporating realistic structure of the atria are lacking. Therefore, we developed image-based models of atrial tissue using structural information extracted from optical coherence tomography (OCT), which can provide volumetric tissue characteristics in high resolution. OCT volumetric data of four swine atrial tissue samples were used to develop models incorporating tissue geometry, tissue-specific myofiber orientation, and ablation lesion regions. We demonstrated the use of these models through electrophysiology and photon scattering simulations. Changes in transmural electrical conduction were observed with the inclusion of OCT-derived, depth-resolved fiber orientation. Additionally, the amplitude of optical mapping signals were not found to correspond with lesion transmurality because of lesion geometry and electrical propagation occurring beyond excitation light penetration. This work established a framework for the development of tissue-specific models of atrial tissue derived from OCT imaging data, which can be useful in future investigations of electrophysiology and optical mapping signals with respect to realistic atrial tissue structure.
Collapse
|
48
|
Martinez-Mateu L, Romero L, Saiz J, Berenfeld O. Far-field contributions in multi-electrodes atrial recordings blur distinction between anatomical and functional reentries and may cause imaginary phase singularities - A computational study. Comput Biol Med 2019; 108:276-287. [PMID: 31015048 DOI: 10.1016/j.compbiomed.2019.02.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Revised: 02/14/2019] [Accepted: 02/21/2019] [Indexed: 01/11/2023]
Abstract
BACKGROUND Atrial fibrillation (AF) is the most common cardiac arrhythmia and the most important cause of embolic stroke, requiring new technologies for its better understanding and therapies. Recent approaches to map the electrical activity during AF with multi-electrode systems aim at localizing patient-specific ablation targets of reentrant patterns. However, there is a critical need to determine the accuracy of those mapping systems. We performed computer simulations as a numerical approach of systematically evaluating the influence of far-field sources on the electrical recordings and detection of rotors. METHODS We constructed 2 computer models of atrial tissue: (i) a 2D sheet model with varying non-active cells area in its center, and (ii) a whole realistic 3D atrial model. Phase maps were built based on the Hilbert transform of the unipolar electrograms recorded by virtual 2D and 3D multi-electrode systems and rotors were tracked through phase singularities detections. RESULTS Analysis of electrograms recorded away from the 2D atrial model shows that the larger the distance between an electrode and the tissue model, the stronger the far-field sources contribution to the electrogram is. Importantly, even if an electrode is positioned in contact with the tissue, the electrogram contains significant contributions from distal sources that blur the distinction between anatomical and functional reentries. Moreover, when mapping the 3D atrial model, remote activity generated false phase singularities at locations without local reentrant excitation patterns. CONCLUSIONS Far-field contributions to electrograms during AF reduce the accuracy of detecting and interpreting reentrant activity.
Collapse
Affiliation(s)
- Laura Martinez-Mateu
- Centro de Investigación e Innovación en Bioingeniería, Universitat Politècnica de València, Valencia, Spain.
| | - Lucia Romero
- Centro de Investigación e Innovación en Bioingeniería, Universitat Politècnica de València, Valencia, Spain
| | - Javier Saiz
- Centro de Investigación e Innovación en Bioingeniería, Universitat Politècnica de València, Valencia, Spain
| | - Omer Berenfeld
- Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI, USA
| |
Collapse
|
49
|
Bear LR, Walton RD, Abell E, Coudière Y, Haissaguerre M, Bernus O, Dubois R. Optical Imaging of Ventricular Action Potentials in a Torso Tank: A New Platform for Non-Invasive Electrocardiographic Imaging Validation. Front Physiol 2019; 10:146. [PMID: 30863318 PMCID: PMC6399141 DOI: 10.3389/fphys.2019.00146] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 02/07/2019] [Indexed: 12/12/2022] Open
Abstract
Background: Non-invasive electrocardiographic imaging (ECGI) is a promising tool to provide high-resolution panoramic imaging of cardiac electrical activity noninvasively from body surface potential measurements. Current experimental methods for ECGI validation are limited to comparison with unipolar electrograms and the relatively low spatial resolution of cardiac mapping arrays. We aim to develop a novel experimental set up combining a human shaped torso tank with high-resolution optical mapping allowing the validation of ECGI reconstructions. Methods: Langendorff-perfused pig hearts (n = 3) were suspended in a human torso-shaped tank, with the left anterior descending artery (LAD) cannulated on a separate perfusion. Electrical signals were recorded from an 108-electrode epicardial sock and 128 electrodes embedded in the tank surface. Simultaneously, optical mapping of the heart was performed through the anterior surface of the tank. Recordings were made in sinus rhythm and ventricular pacing (n = 55), with activation and repolarization heterogeneities induced by perfusion of hot and cold solutions as well as Sotalol through the LAD. Fluoroscopy provided 3D cardiac and electrode geometries in the tank that were transformed to the 2D optical mapping window using an optimization algorithm. Epicardial unipolar electrograms were reconstructed from torso potentials using ECGI and validated using optical activation and repolarization maps. Results: The transformation and alignment of the 3D geometries onto the 2D optical mapping window was good with an average correlation of 0.87 ± 0.10 and error of 7.7 ± 3.1 ms with activation derived from the sock. The difference in repolarization times were more substantial (error = 17.4 ± 3.7 ms) although the sock and optical repolarization patterns themselves were very similar (correlation = 0.83 ± 0.13). Validation of ECGI reconstructions revealed ECGI accurately captures the pattern of activation (correlation = 0.79 ± 0.11) and identified regions of late and/or early repolarization during different perfusions through LAD. ECGI also correctly demonstrated gradients in both activation and repolarization, although in some cases these were under or over-estimated or shifted slightly in space. Conclusion: A novel experimental setup has been developed, combining a human-shaped torso tank with optical mapping, which can be effectively used in the validation of ECGI techniques; including the reconstruction of activation and repolarization patterns and gradients.
Collapse
Affiliation(s)
- Laura R Bear
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université, Bordeaux, France.,Univ. Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, Bordeaux, France.,INSERM, Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, Bordeaux, France
| | - Richard D Walton
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université, Bordeaux, France.,Univ. Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, Bordeaux, France.,INSERM, Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, Bordeaux, France
| | - Emma Abell
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université, Bordeaux, France.,Univ. Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, Bordeaux, France.,INSERM, Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, Bordeaux, France
| | - Yves Coudière
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université, Bordeaux, France.,Univ. Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, Bordeaux, France.,CARMEN Research Team, INRIA, Talence, France.,CNRS, IMB, UMR 5251, Talence, France
| | - Michel Haissaguerre
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université, Bordeaux, France.,Univ. Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, Bordeaux, France.,INSERM, Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, Bordeaux, France.,Bordeaux University Hospital (CHU), Electrophysiology and Ablation Unit, Pessac, France
| | - Olivier Bernus
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université, Bordeaux, France.,Univ. Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, Bordeaux, France.,INSERM, Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, Bordeaux, France
| | - Rémi Dubois
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université, Bordeaux, France.,Univ. Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, Bordeaux, France.,INSERM, Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, Bordeaux, France
| |
Collapse
|
50
|
Cathey B, Obaid S, Zolotarev AM, Pryamonosov RA, Syunyaev RA, George SA, Efimov IR. Open-Source Multiparametric Optocardiography. Sci Rep 2019; 9:721. [PMID: 30679527 PMCID: PMC6346041 DOI: 10.1038/s41598-018-36809-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 11/27/2018] [Indexed: 01/17/2023] Open
Abstract
Since the 1970s fluorescence imaging has become a leading tool in the discovery of mechanisms of cardiac function and arrhythmias. Gradual improvements in fluorescent probes and multi-camera technology have increased the power of optical mapping and made a major impact on the field of cardiac electrophysiology. Tandem-lens optical mapping systems facilitated simultaneous recording of multiple parameters characterizing cardiac function. However, high cost and technological complexity restricted its proliferation to the wider biological community. We present here, an open-source solution for multiple-camera tandem-lens optical systems for multiparametric mapping of transmembrane potential, intracellular calcium dynamics and other parameters in intact mouse hearts and in rat heart slices. This 3D-printable hardware and Matlab-based RHYTHM 1.2 analysis software are distributed under an MIT open-source license. Rapid prototyping permits the development of inexpensive, customized systems with broad functionality, allowing wider application of this technology outside biomedical engineering laboratories.
Collapse
Affiliation(s)
- Brianna Cathey
- Department of Biomedical Engineering, George Washington University, Washington, DC, 20052, USA
| | - Sofian Obaid
- Department of Biomedical Engineering, George Washington University, Washington, DC, 20052, USA
| | - Alexander M Zolotarev
- Laboratory of Human Physiology, Moscow Institute of Physics and Technology, Moscow, Russia
| | - Roman A Pryamonosov
- Laboratory of Human Physiology, Moscow Institute of Physics and Technology, Moscow, Russia
- Institute of Personalized Medicine, Sechenov University, Moscow, Russia
| | - Roman A Syunyaev
- Laboratory of Human Physiology, Moscow Institute of Physics and Technology, Moscow, Russia
- Institute of Personalized Medicine, Sechenov University, Moscow, Russia
| | - Sharon A George
- Department of Biomedical Engineering, George Washington University, Washington, DC, 20052, USA.
| | - Igor R Efimov
- Department of Biomedical Engineering, George Washington University, Washington, DC, 20052, USA.
- Laboratory of Human Physiology, Moscow Institute of Physics and Technology, Moscow, Russia.
| |
Collapse
|