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Trayanova NA, Lyon A, Shade J, Heijman J. Computational modeling of cardiac electrophysiology and arrhythmogenesis: toward clinical translation. Physiol Rev 2024; 104:1265-1333. [PMID: 38153307 DOI: 10.1152/physrev.00017.2023] [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: 04/05/2023] [Revised: 12/19/2023] [Accepted: 12/21/2023] [Indexed: 12/29/2023] Open
Abstract
The complexity of cardiac electrophysiology, involving dynamic changes in numerous components across multiple spatial (from ion channel to organ) and temporal (from milliseconds to days) scales, makes an intuitive or empirical analysis of cardiac arrhythmogenesis challenging. Multiscale mechanistic computational models of cardiac electrophysiology provide precise control over individual parameters, and their reproducibility enables a thorough assessment of arrhythmia mechanisms. This review provides a comprehensive analysis of models of cardiac electrophysiology and arrhythmias, from the single cell to the organ level, and how they can be leveraged to better understand rhythm disorders in cardiac disease and to improve heart patient care. Key issues related to model development based on experimental data are discussed, and major families of human cardiomyocyte models and their applications are highlighted. An overview of organ-level computational modeling of cardiac electrophysiology and its clinical applications in personalized arrhythmia risk assessment and patient-specific therapy of atrial and ventricular arrhythmias is provided. The advancements presented here highlight how patient-specific computational models of the heart reconstructed from patient data have achieved success in predicting risk of sudden cardiac death and guiding optimal treatments of heart rhythm disorders. Finally, an outlook toward potential future advances, including the combination of mechanistic modeling and machine learning/artificial intelligence, is provided. As the field of cardiology is embarking on a journey toward precision medicine, personalized modeling of the heart is expected to become a key technology to guide pharmaceutical therapy, deployment of devices, and surgical interventions.
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Affiliation(s)
- Natalia A Trayanova
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, United States
- Alliance for Cardiovascular Diagnostic and Treatment Innovation, Johns Hopkins University, Baltimore, Maryland, United States
| | - Aurore Lyon
- Department of Biomedical Engineering, CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, The Netherlands
- Division of Heart and Lungs, Department of Medical Physiology, University Medical Centre Utrecht, Utrecht, The Netherlands
| | - Julie Shade
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, United States
- Alliance for Cardiovascular Diagnostic and Treatment Innovation, Johns Hopkins University, Baltimore, Maryland, United States
| | - Jordi Heijman
- Department of Cardiology, CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, The Netherlands
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Zhu J, Bai J, Zhou Z, Liang Y, Chen Z, Chen X, Zhang X. RAS Dataset: A 3D Cardiac LGE-MRI Dataset for Segmentation of Right Atrial Cavity. Sci Data 2024; 11:401. [PMID: 38643183 PMCID: PMC11032400 DOI: 10.1038/s41597-024-03253-9] [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: 10/30/2023] [Accepted: 04/11/2024] [Indexed: 04/22/2024] Open
Abstract
The current challenge in effectively treating atrial fibrillation (AF) stems from a limited understanding of the intricate structure of the human atria. The objective and quantitative interpretation of the right atrium (RA) in late gadolinium-enhanced magnetic resonance imaging (LGE-MRI) scans relies heavily on its precise segmentation. Leveraging the potential of artificial intelligence (AI) for RA segmentation presents a promising solution. However, the successful implementation of AI in this context necessitates access to a substantial volume of annotated LGE-MRI images for model training. In this paper, we present a comprehensive 3D cardiac dataset comprising 50 high-resolution LGE-MRI scans, each meticulously annotated at the pixel level. The annotation process underwent rigorous standardization through crowdsourcing among a panel of medical experts, ensuring the accuracy and consistency of the annotations. Our dataset represents a significant contribution to the field, providing a valuable resource for advancing RA segmentation methods.
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Affiliation(s)
- Jinwen Zhu
- Department of Electronic Engineering, College of Information Science and Technology, Jinan University, Guangzhou, China
| | - Jieyun Bai
- Department of Electronic Engineering, College of Information Science and Technology, Jinan University, Guangzhou, China.
- Auckland Bioengineering Institute, the University of Auckland, Auckland, New Zealand.
| | - Zihao Zhou
- Department of Electronic Engineering, College of Information Science and Technology, Jinan University, Guangzhou, China
| | - Yaqi Liang
- Department of Electronic Engineering, College of Information Science and Technology, Jinan University, Guangzhou, China
| | - Zhiting Chen
- Department of Electronic Engineering, College of Information Science and Technology, Jinan University, Guangzhou, China
| | - Xiaoming Chen
- Department of Cardiology, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Xiaoshen Zhang
- Department of Cardiology, The First Affiliated Hospital of Jinan University, Guangzhou, China
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3
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Zhang Z, Vlcek J, Pauly V, Hesse N, Bauer J, Chataut KR, Maderspacher F, Volz LS, Buchberger K, Xia R, Hildebrand B, Kääb S, Schüttler D, Tomsits P, Clauss S. Atrial fibrosis heterogeneity is a risk for atrial fibrillation in pigs with ischaemic heart failure. Eur J Clin Invest 2024; 54:e14137. [PMID: 38012826 DOI: 10.1111/eci.14137] [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: 08/01/2023] [Revised: 11/02/2023] [Accepted: 11/18/2023] [Indexed: 11/29/2023]
Abstract
BACKGROUND Atrial fibrillation (AF) is the most common arrhythmia and is associated with considerable morbidity and mortality. Ischaemic heart failure (IHF) remains one of the most common causes of AF in clinical practice. However, ischaemia-mediated mechanisms leading to AF are still incompletely understood, and thus, current treatment approaches are limited. To improve our understanding of the pathophysiology, we studied a porcine IHF model. METHODS In pigs, IHF was induced by balloon occlusion of the left anterior descending artery for 90 min. After 30 days of reperfusion, invasive haemodynamic measurements and electrophysiological studies were performed. Masson trichrome and immunofluorescence staining were conducted to assess interstitial fibrosis and myofibroblast activation in different heart regions. RESULTS After 30 days of reperfusion, heart failure with significantly reduced ejection fraction (left anterior obique 30°, 34.78 ± 3.29% [IHF] vs. 62.03 ± 2.36% [control], p < .001; anterior-posterior 0°, 29.16 ± 3.61% vs. 59.54 ± 1.09%, p < .01) was observed. These pigs showed a significantly higher susceptibility to AF (33.90% [IHF] vs. 12.98% [control], p < .05). Histological assessment revealed aggravated fibrosis in atrial appendages but not in atrial free walls in IHF pigs (11.13 ± 1.44% vs. 5.99 ± .86%, p < .01 [LAA], 8.28 ± .56% vs. 6.01 ± .35%, p < .01 [RAA]), which was paralleled by enhanced myofibroblast activation (12.09 ± .65% vs. 9.00 ± .94%, p < .05 [LAA], 14.37 ± .60% vs. 10.30 ± 1.41%, p < .05 [RAA]). Correlation analysis indicated that not fibrosis per se but its cross-regional heterogeneous distribution across the left atrium was associated with AF susceptibility (r = .6344, p < .01). CONCLUSION Our results suggest that left atrial cross-regional fibrosis difference rather than overall fibrosis level is associated with IHF-related AF susceptibility, presumably by establishing local conduction disturbances and heterogeneity.
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Affiliation(s)
- Zhihao Zhang
- Department of Medicine I, Campus Grosshadern, University Hospital Munich, Ludwig-Maximilians University (LMU), Munich, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Munich, Munich Heart Alliance, Munich, Germany
- Institute of Surgical Research at the Walter-Brendel-Centre of Experimental Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Julia Vlcek
- Department of Medicine I, Campus Grosshadern, University Hospital Munich, Ludwig-Maximilians University (LMU), Munich, Germany
- Institute of Surgical Research at the Walter-Brendel-Centre of Experimental Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Valerie Pauly
- Department of Medicine I, Campus Grosshadern, University Hospital Munich, Ludwig-Maximilians University (LMU), Munich, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Munich, Munich Heart Alliance, Munich, Germany
- Institute of Surgical Research at the Walter-Brendel-Centre of Experimental Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Nora Hesse
- Department of Medicine I, Campus Grosshadern, University Hospital Munich, Ludwig-Maximilians University (LMU), Munich, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Munich, Munich Heart Alliance, Munich, Germany
- Institute of Surgical Research at the Walter-Brendel-Centre of Experimental Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Julia Bauer
- Department of Medicine I, Campus Grosshadern, University Hospital Munich, Ludwig-Maximilians University (LMU), Munich, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Munich, Munich Heart Alliance, Munich, Germany
- Institute of Surgical Research at the Walter-Brendel-Centre of Experimental Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Kavi Raj Chataut
- Department of Medicine I, Campus Grosshadern, University Hospital Munich, Ludwig-Maximilians University (LMU), Munich, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Munich, Munich Heart Alliance, Munich, Germany
- Institute of Surgical Research at the Walter-Brendel-Centre of Experimental Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Florian Maderspacher
- Department of Medicine I, Campus Grosshadern, University Hospital Munich, Ludwig-Maximilians University (LMU), Munich, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Munich, Munich Heart Alliance, Munich, Germany
- Institute of Surgical Research at the Walter-Brendel-Centre of Experimental Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Lina Sophie Volz
- Department of Medicine I, Campus Grosshadern, University Hospital Munich, Ludwig-Maximilians University (LMU), Munich, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Munich, Munich Heart Alliance, Munich, Germany
- Institute of Surgical Research at the Walter-Brendel-Centre of Experimental Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Katharina Buchberger
- Department of Medicine I, Campus Grosshadern, University Hospital Munich, Ludwig-Maximilians University (LMU), Munich, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Munich, Munich Heart Alliance, Munich, Germany
- Institute of Surgical Research at the Walter-Brendel-Centre of Experimental Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Ruibing Xia
- Department of Medicine I, Campus Grosshadern, University Hospital Munich, Ludwig-Maximilians University (LMU), Munich, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Munich, Munich Heart Alliance, Munich, Germany
- Institute of Surgical Research at the Walter-Brendel-Centre of Experimental Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Bianca Hildebrand
- Department of Medicine I, Campus Grosshadern, University Hospital Munich, Ludwig-Maximilians University (LMU), Munich, Germany
| | - Stefan Kääb
- Department of Medicine I, Campus Grosshadern, University Hospital Munich, Ludwig-Maximilians University (LMU), Munich, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Munich, Munich Heart Alliance, Munich, Germany
- Interfaculty Center for Endocrine and Cardiovascular Disease Network Modelling and Clinical Transfer (ICONLMU), LMU Munich, Munich, Germany
| | - Dominik Schüttler
- Department of Medicine I, Campus Grosshadern, University Hospital Munich, Ludwig-Maximilians University (LMU), Munich, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Munich, Munich Heart Alliance, Munich, Germany
- Institute of Surgical Research at the Walter-Brendel-Centre of Experimental Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Philipp Tomsits
- Department of Medicine I, Campus Grosshadern, University Hospital Munich, Ludwig-Maximilians University (LMU), Munich, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Munich, Munich Heart Alliance, Munich, Germany
- Institute of Surgical Research at the Walter-Brendel-Centre of Experimental Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Sebastian Clauss
- Department of Medicine I, Campus Grosshadern, University Hospital Munich, Ludwig-Maximilians University (LMU), Munich, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Munich, Munich Heart Alliance, Munich, Germany
- Institute of Surgical Research at the Walter-Brendel-Centre of Experimental Medicine, University Hospital, LMU Munich, Munich, Germany
- Interfaculty Center for Endocrine and Cardiovascular Disease Network Modelling and Clinical Transfer (ICONLMU), LMU Munich, Munich, Germany
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Li DL, Hajjar AHE, Ayoub T, Zhang Y, Huang C, Kholmovski EG, Mekhael M, Noujaim C, Feng H, Lim C, Marrouche NF. Left atrial volume affects the correlation of voltage map with magnetic resonance imaging. J Interv Card Electrophysiol 2024; 67:263-271. [PMID: 36973597 DOI: 10.1007/s10840-023-01522-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 03/02/2023] [Indexed: 03/29/2023]
Abstract
BACKGROUND The low-voltage area detected by electroanatomic mapping (EAM) is a surrogate marker of left atrial fibrosis. However, the correlation between the EAM and late gadolinium enhancement magnetic resonance imaging (LGE-MRI) has been inconsistent among studies. This study aimed to investigate how LA size affects the correlation between EAM and LGE-MRI. METHODS High-density EAMs of the LA during sinus rhythm were collected in 22 patients undergoing AF ablation. The EAMs were co-registered with pre-ablation LGE-MRI models. Voltages in the areas with and without LGE were recorded. Left atrial volume index (LAVI) was calculated from MRI, and LAVI > 62 ml/m2 was defined as significant LA enlargement (LAE). RESULTS Atrial bipolar voltage negatively correlates with the left atrial volume index. The median voltages in areas without LGE were 1.1 mV vs 2.0 mV in patients with vs without significant LAE (p = 0.002). In areas of LGE, median voltages were 0.4 mV vs 0.8 mV in patients with vs without significant LAE (p = 0.02). A voltage threshold of 1.7 mV predicted atrial LGE in patients with normal or mildly enlarged LA (sensitivity and specificity of 74% and 59%, respectively). In contrast, areas of voltage less than 0.75 mV correlated with LGE in patients with significant LA enlargement (sensitivity 68% and specificity 66%). CONCLUSIONS LAVI affects left atrial bipolar voltage, and the correlation between low-voltage areas and LGE-MRI. Distinct voltage thresholds according to the LAVI value might be considered to identify atrial scar by EAM.
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Affiliation(s)
- Dan L Li
- Cardiac Electrophysiology Section, Department of Internal Medicine and Cardiology, Tulane University School of Medicine, New Orleans, LA, 70112, USA
- Tulane Research and Innovation for Arrhythmia Discoveries, New Orleans, LA, USA
| | | | - Tarek Ayoub
- Cardiac Electrophysiology Section, Department of Internal Medicine and Cardiology, Tulane University School of Medicine, New Orleans, LA, 70112, USA
- Tulane Research and Innovation for Arrhythmia Discoveries, New Orleans, LA, USA
| | - Yichi Zhang
- Tulane Research and Innovation for Arrhythmia Discoveries, New Orleans, LA, USA
| | - Chao Huang
- Tulane Research and Innovation for Arrhythmia Discoveries, New Orleans, LA, USA
| | - Eugene G Kholmovski
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Mario Mekhael
- Tulane Research and Innovation for Arrhythmia Discoveries, New Orleans, LA, USA
| | - Charbel Noujaim
- Tulane Research and Innovation for Arrhythmia Discoveries, New Orleans, LA, USA
| | - Han Feng
- Tulane Research and Innovation for Arrhythmia Discoveries, New Orleans, LA, USA
| | - Chanho Lim
- Tulane Research and Innovation for Arrhythmia Discoveries, New Orleans, LA, USA
| | - Nassir F Marrouche
- Cardiac Electrophysiology Section, Department of Internal Medicine and Cardiology, Tulane University School of Medicine, New Orleans, LA, 70112, USA.
- Tulane Research and Innovation for Arrhythmia Discoveries, New Orleans, LA, USA.
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5
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Cau R, Muscogiuri G, Pisu F, Mannelli L, Sironi S, Suri JS, Pontone G, Saba L. Effect of late gadolinium enhancement on left atrial impairment in myocarditis patients. Eur Radiol 2024; 34:1846-1853. [PMID: 37658889 PMCID: PMC10873434 DOI: 10.1007/s00330-023-10176-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Revised: 06/13/2023] [Accepted: 07/04/2023] [Indexed: 09/05/2023]
Abstract
OBJECTIVE The aims of our study were to investigate the effect of the extent and location of late gadolinium enhancement (LGE) on the left atrium (LA) function in patients with acute myocarditis (AM) using cardiovascular magnetic resonance (CMR). METHOD This retrospective study performed CMR scans in 113 consecutive patients (89 males, 24 females; mean age 45.8 ± 17.3 years) with AM that met the updated Lake Louise criteria. Reservoir, conduit, and booster LA functions were analyzed by CMR feature tracking using dedicated software. Besides LA strain measurements, myocardial scar location and extent were assigned and quantified by LGE imaging. RESULTS AM patients with septal LGE had impaired reservoir, conduit, and conduit strain rate function in comparison with AM patients with non-septal LGE (p = 0.001, for all). In fully adjusted multivariable linear regression, reservoir and conduit were significantly associated with left ventricle (LV) LGE location (β coefficient = 8.205, p = 0.007; β coefficient = 5.185, p = 0.026; respectively). In addition, LA parameters decreased according to the increase in the extent of LV fibrosis (LGE ≤ 10%; LGE 11-19%; LGE ≥ 20%). After adjustment in multivariable linear regression, the association with LV LGE extent was no longer statistically significant. CONCLUSION In patients with acute myocarditis, LA function abnormalities are significantly associated with LV LGE location, but not with LGE extent. Septal LGE is paralleled by a deterioration of LA reservoir and conduit function. CLINICAL RELEVANCE STATEMENT Left atrium dysfunction is associated with the presence of late gadolinium enhancement in the left ventricle septum and can be useful in the clinical prognostication of patients with acute myocarditis, allowing individually tailored treatment. KEY POINTS • Myocardial fibrosis is related to atrial impairment. • The location of myocardial fibrosis is the main determinant of atrial dysfunction in myocarditis patients. • The quantification of atrial mechanisms may provide more in-depth insight into myocarditis pathophysiology.
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Affiliation(s)
- Riccardo Cau
- Department of Radiology, Azienda Ospedaliero Universitaria (A.O.U.), di Cagliari - Polo di Monserrato s.s. 554 Monserrato, 09045, Cagliari, Italy
| | - Giuseppe Muscogiuri
- School of Medicine and Surgery, University of Milano-Bicocca, Milan, Italy
- Department of Radiology, IRCCS Istituto Auxologico Italiano, San Luca Hospital, Milan, Italy
| | - Francesco Pisu
- Department of Radiology, Azienda Ospedaliero Universitaria (A.O.U.), di Cagliari - Polo di Monserrato s.s. 554 Monserrato, 09045, Cagliari, Italy
| | - Lorenzo Mannelli
- Department of Radiology, IRCCS Istituto Auxologico Italiano, San Luca Hospital, Milan, Italy
| | - Sandro Sironi
- School of Medicine and Surgery, University of Milano-Bicocca, Milan, Italy
- Department of Radiology, ASST Papa Giovanni XXIII Hospital, Bergamo, Italy
| | - Jasjit S Suri
- Stroke Monitoring and Diagnostic Division, AtheroPoint™, Roseville, CA, USA
| | - Gianluca Pontone
- Department of Perioperative Cardiology and Cardiovascular Imaging, Centro Cardiologico Monzino IRCCS, Milan, Italy
- Department of Biomedical, Surgical and Dental Sciences, University of Milan, Milan, Italy
| | - Luca Saba
- Department of Radiology, Azienda Ospedaliero Universitaria (A.O.U.), di Cagliari - Polo di Monserrato s.s. 554 Monserrato, 09045, Cagliari, Italy.
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Colman MA, Sharma R, Aslanidi OV, Zhao J. Patchy fibrosis promotes trigger-substrate interactions that both generate and maintain atrial fibrillation. Interface Focus 2023; 13:20230041. [PMID: 38106913 PMCID: PMC10722214 DOI: 10.1098/rsfs.2023.0041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Accepted: 11/15/2023] [Indexed: 12/19/2023] Open
Abstract
Fibrosis has been mechanistically linked to arrhythmogenesis in multiple cardiovascular conditions, including atrial fibrillation (AF). Previous studies have demonstrated that fibrosis can create functional barriers to conduction which may promote excitation wavebreak and the generation of re-entry, while also acting to pin re-entrant excitation in stable rotors during AF. However, few studies have investigated the role of fibrosis in the generation of AF triggers in detail. We apply our in-house computational framework to study the impact of fibrosis on the generation of AF triggers and trigger-substrate interactions in two- and three-dimensional atrial tissue models. Our models include a reduced and efficient description of stochastic, spontaneous cellular triggers as well as a simple model of heterogeneous inter-cellular coupling. Our results demonstrate that fibrosis promotes the emergence of focal excitations, primarily through reducing the electrotonic load on individual fibre strands. This enables excitation to robustly initiate within these single strands before spreading to neighbouring strands and inducing a full tissue focal excitation. Enhanced conduction block can allow trigger-substrate interactions that result in the emergence of complex, re-entrant excitation patterns. This study provides new insight into the mechanisms by which fibrosis promotes the triggers and substrate necessary to induce and sustain arrhythmia.
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Affiliation(s)
| | - Roshan Sharma
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Oleg V. Aslanidi
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
| | - Jichao Zhao
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
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7
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Nairn D, Eichenlaub M, Müller-Edenborn B, Huang T, Lehrmann H, Nagel C, Azzolin L, Luongo G, Figueras Ventura RM, Rubio Forcada B, Vallès Colomer A, Westermann D, Arentz T, Dössel O, Loewe A, Jadidi A. Differences in atrial substrate localization using late gadolinium enhancement-magnetic resonance imaging, electrogram voltage, and conduction velocity: a cohort study using a consistent anatomical reference frame in patients with persistent atrial fibrillation. Europace 2023; 25:euad278. [PMID: 37713626 PMCID: PMC10533207 DOI: 10.1093/europace/euad278] [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: 06/12/2023] [Accepted: 09/10/2023] [Indexed: 09/17/2023] Open
Abstract
AIMS Electro-anatomical voltage, conduction velocity (CV) mapping, and late gadolinium enhancement (LGE) magnetic resonance imaging (MRI) have been correlated with atrial cardiomyopathy (ACM). However, the comparability between these modalities remains unclear. This study aims to (i) compare pathological substrate extent and location between current modalities, (ii) establish spatial histograms in a cohort, (iii) develop a new estimated optimized image intensity threshold (EOIIT) for LGE-MRI identifying patients with ACM, (iv) predict rhythm outcome after pulmonary vein isolation (PVI) for persistent atrial fibrillation (AF). METHODS AND RESULTS Thirty-six ablation-naive persistent AF patients underwent LGE-MRI and high-definition electro-anatomical mapping in sinus rhythm. Late gadolinium enhancement areas were classified using the UTAH, image intensity ratio (IIR >1.20), and new EOIIT method for comparison to low-voltage substrate (LVS) and slow conduction areas <0.2 m/s. Receiver operating characteristic analysis was used to determine LGE thresholds optimally matching LVS. Atrial cardiomyopathy was defined as LVS extent ≥5% of the left atrium (LA) surface at <0.5 mV. The degree and distribution of detected pathological substrate (percentage of individual LA surface are) varied significantly (P < 0.001) across the mapping modalities: 10% (interquartile range 0-14%) of the LA displayed LVS <0.5 mV vs. 7% (0-12%) slow conduction areas <0.2 m/s vs. 15% (8-23%) LGE with the UTAH method vs. 13% (2-23%) using IIR >1.20, with most discrepancies on the posterior LA. Optimized image intensity thresholds and each patient's mean blood pool intensity correlated linearly (R2 = 0.89, P < 0.001). Concordance between LGE-MRI-based and LVS-based ACM diagnosis improved with the novel EOIIT applied at the anterior LA [83% sensitivity, 79% specificity, area under the curve (AUC): 0.89] in comparison to the UTAH method (67% sensitivity, 75% specificity, AUC: 0.81) and IIR >1.20 (75% sensitivity, 62% specificity, AUC: 0.67). CONCLUSION Discordances in detected pathological substrate exist between LVS, CV, and LGE-MRI in the LA, irrespective of the LGE detection method. The new EOIIT method improves concordance of LGE-MRI-based ACM diagnosis with LVS in ablation-naive AF patients but discrepancy remains particularly on the posterior wall. All methods may enable the prediction of rhythm outcomes after PVI in patients with persistent AF.
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Affiliation(s)
- Deborah Nairn
- Institute of Biomedical Engineering, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 1, Karlsruhe 76131, Germany
| | - Martin Eichenlaub
- Department of Cardiology and Angiology, Medical Center, University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Björn Müller-Edenborn
- Department of Cardiology and Angiology, Medical Center, University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Taiyuan Huang
- Department of Cardiology and Angiology, Medical Center, University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Heiko Lehrmann
- Department of Cardiology and Angiology, Medical Center, University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Claudia Nagel
- Institute of Biomedical Engineering, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 1, Karlsruhe 76131, Germany
| | - Luca Azzolin
- Institute of Biomedical Engineering, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 1, Karlsruhe 76131, Germany
| | - Giorgio Luongo
- Institute of Biomedical Engineering, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 1, Karlsruhe 76131, Germany
| | | | | | | | - Dirk Westermann
- Department of Cardiology and Angiology, Medical Center, University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Thomas Arentz
- Department of Cardiology and Angiology, Medical Center, University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Olaf Dössel
- Institute of Biomedical Engineering, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 1, Karlsruhe 76131, Germany
| | - Axel Loewe
- Institute of Biomedical Engineering, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 1, Karlsruhe 76131, Germany
| | - Amir Jadidi
- Department of Cardiology and Angiology, Medical Center, University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Arrhythmia Division, Department of Cardiology, Heart Center Lucerne, Lucerne Cantonal Hospital, Lucerne, Switzerland
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8
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Nishimura A, Harada M, Ashihara T, Nomura Y, Motoike Y, Koshikawa M, Ito T, Watanabe E, Ozaki Y, Izawa H. Effect of pulmonary vein isolation on rotor/multiple wavelet dynamics in persistent atrial fibrillation, association with vagal response and implications for adjunctive ablation. Heart Vessels 2022; 38:699-710. [PMID: 36436027 PMCID: PMC10085924 DOI: 10.1007/s00380-022-02209-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 11/16/2022] [Indexed: 11/29/2022]
Abstract
AbstractPersistent atrial fibrillation (PeAF) may develop arrhythmogenic substrates of rotors/multiple wavelets. However, the ways in which pulmonary vein isolation (PVI) affects the dynamics of rotor/multiple wavelets in PeAF patients remain elusive. Real-time phase-mapping (ExTRa mapping, EXT) in the whole left atrium (LA) was performed during PeAF before and after PVI (n = 111). The percentage of time in which rotor/multiple wavelets (phase singularities) was observed during each 5-s phase-mapping recording (non-passive activation ratio, %NP) was measured as an index of its burden. The mapping areas showing %NP ≥ 50% were defined as rotor/multiple-wavelet substrates (RSs). Before PVI, RSs were globally distributed in the LA. After PVI, %NP decreased (< 50%) in many RSs (PVI-modifiable RSs) but remained high (≥ 50%) in some RSs, especially localized in the anterior/septum/inferior regions (PVI-unmodifiable RSs, 2.3 ± 1.0 areas/patient). Before PVI, vagal response (VR) to high-frequency stimulation was observed in 23% of RSs, especially localized in the inferior region. VR disappearance after PVI was more frequently observed in PVI-modifiable RSs (79%) than in PVI-unmodifiable RSs (55%, p < 0.05), suggesting that PVI affects autonomic nerve activities and rotor/multiple wavelet dynamics. PVI-unmodifiable RSs were adjunctively ablated in 104 patients. The 1-year AT/AF-free survival rate was 70% in those with PVI alone (n = 115), and 86% in patients with the adjunctive ablation (log-rank test = 7.65, p < 0.01). PVI suppresses not only ectopic firing but also rotor/multiple wavelets partly via modification of autonomic nerve activities. The adjunctive ablation of PVI-unmodifiable RSs improved the outcome in PeAF patients and might be a novel ablation strategy beyond PVI.
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Affiliation(s)
- Asuka Nishimura
- Department of Cardiology, Fujita Health University, 1-98 Dengakugakubo, Kutsukake-Cho, Toyoake, Aichi, 4701192, Japan
| | - Masahide Harada
- Department of Cardiology, Fujita Health University, 1-98 Dengakugakubo, Kutsukake-Cho, Toyoake, Aichi, 4701192, Japan.
| | - Takashi Ashihara
- Information Technology and Management Center, Shiga University of Medical Science, Seta Tsukinowa-Cho, Otsu, Shiga, 5202192, Japan
| | - Yoshihiro Nomura
- Department of Cardiology, Fujita Health University, 1-98 Dengakugakubo, Kutsukake-Cho, Toyoake, Aichi, 4701192, Japan
| | - Yuji Motoike
- Department of Cardiology, Fujita Health University, 1-98 Dengakugakubo, Kutsukake-Cho, Toyoake, Aichi, 4701192, Japan
| | - Masayuki Koshikawa
- Department of Cardiology, Fujita Health University, 1-98 Dengakugakubo, Kutsukake-Cho, Toyoake, Aichi, 4701192, Japan
| | - Takehiro Ito
- Department of Cardiology, Fujita Health University, 1-98 Dengakugakubo, Kutsukake-Cho, Toyoake, Aichi, 4701192, Japan
| | - Eiichi Watanabe
- Department of Cardiology, Fujita Health University, 1-98 Dengakugakubo, Kutsukake-Cho, Toyoake, Aichi, 4701192, Japan
| | - Yukio Ozaki
- Department of Cardiology, Fujita Health University, 1-98 Dengakugakubo, Kutsukake-Cho, Toyoake, Aichi, 4701192, Japan
| | - Hideo Izawa
- Department of Cardiology, Fujita Health University, 1-98 Dengakugakubo, Kutsukake-Cho, Toyoake, Aichi, 4701192, Japan
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9
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Yamamoto C, Trayanova NA. Atrial fibrillation: Insights from animal models, computational modeling, and clinical studies. EBioMedicine 2022; 85:104310. [PMID: 36309006 PMCID: PMC9619190 DOI: 10.1016/j.ebiom.2022.104310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 09/25/2022] [Accepted: 10/04/2022] [Indexed: 11/11/2022] Open
Abstract
Atrial fibrillation (AF) is the most common human arrhythmia, affecting millions of patients worldwide. A combination of risk factors and comorbidities results in complex atrial remodeling, which increases AF vulnerability and persistence. Insights from animal models, clinical studies, and computational modeling have advanced the understanding of the mechanisms and pathophysiology of AF. Areas of heterogeneous pathological remodeling, as well as altered electrophysiological properties, serve as a substrate for AF drivers and spontaneous activations. The complex and individualized presentation of this arrhythmia suggests that mechanisms-based personalized approaches will likely be needed to overcome current challenges in AF management. In this paper, we review the insights on the mechanisms of AF obtained from animal models and clinical studies and how computational models integrate this knowledge to advance AF clinical management. We also assess the challenges that need to be overcome to implement these mechanistic models in clinical practice.
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Affiliation(s)
- Carolyna Yamamoto
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Natalia A. Trayanova
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA,Alliance for Cardiovascular Diagnostic and Treatment Innovation (ADVANCE), Johns Hopkins University, Baltimore, MD, USA,Corresponding author. Johns Hopkins, Johns Hopkins University, United States.
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10
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Ivanov V, Smereka Y, Rasputin V, Dmytriiev K. Homocysteine and atrial fibrillation: novel evidences and insights. Monaldi Arch Chest Dis 2022; 93. [PMID: 35443572 DOI: 10.4081/monaldi.2022.2241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Accepted: 04/09/2022] [Indexed: 12/27/2022] Open
Abstract
Atrial fibrillation (AF) is one of the most prevalent rhythm disorders worldwide, with around 37.574 million cases around the globe (0.51 % global population). Different studies showed a high informative value of different biomarkers, including such related to the systemic inflammation, biomechanical stress and fibrosis. In this review article we aimed to study only the relation of homocysteine to the AF development. Homocysteine is a sulfur-containing amino acid, that is produced in the process of methionine metabolism. Which is a non-canonical amino acid, that is derived from the food proteins. From the scientific point of view there is a relation between hyperhomocysteinemia and myocardial fibrosis, but these mechanisms are complicated and not sufficiently studied. Homocysteine regulates activity of the ion channels through their redox state. Elevated homocysteine level can condition electrical remodeling of the cardiomyocytes through the increase of sodium current and change in the function of rapid sodium channels, increase of inwards potassium current and decrease in amount of rapid potassium channels. High homocysteine concentration also leads to the shortening of the action potential, loss of the rate adaptation of the action potential and persistent circulation of the re-entry waves. In a series of experimental studies on mice there was an association found between the homocysteine level and activity of vascular inflammation. Elevation of homocysteine level is an independent factor of the thromboembolic events and AF relapses. Population studies showed, that homocysteine is an independent risk factor for AF. So, homocysteine is an interesting target for up-stream therapy.
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Affiliation(s)
- Valeriy Ivanov
- Vinnytsia National Pirogov Memorial Medical University, Vinnytsia.
| | - Yuliia Smereka
- Vinnytsia Regional Clinical Center of Cardiovascular Pathology, Vinnytsia.
| | - Volodymyr Rasputin
- Vinnytsia Regional Clinical Center of Cardiovascular Pathology, Vinnytsia.
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11
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Giardini F, Lazzeri E, Vitale G, Ferrantini C, Costantini I, Pavone FS, Poggesi C, Bocchi L, Sacconi L. Quantification of Myocyte Disarray in Human Cardiac Tissue. Front Physiol 2021; 12:750364. [PMID: 34867455 PMCID: PMC8635020 DOI: 10.3389/fphys.2021.750364] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 09/24/2021] [Indexed: 11/13/2022] Open
Abstract
Proper three-dimensional (3D)-cardiomyocyte orientation is important for an effective tension production in cardiac muscle. Cardiac diseases can cause severe remodeling processes in the heart, such as cellular misalignment, that can affect both the electrical and mechanical functions of the organ. To date, a proven methodology to map and quantify myocytes disarray in massive samples is missing. In this study, we present an experimental pipeline to reconstruct and analyze the 3D cardiomyocyte architecture in massive samples. We employed tissue clearing, staining, and advanced microscopy techniques to detect sarcomeres in relatively large human myocardial strips with micrometric resolution. Z-bands periodicity was exploited in a frequency analysis approach to extract the 3D myofilament orientation, providing an orientation map used to characterize the tissue organization at different spatial scales. As a proof-of-principle, we applied the proposed method to healthy and pathologically remodeled human cardiac tissue strips. Preliminary results suggest the reliability of the method: strips from a healthy donor are characterized by a well-organized tissue, where the local disarray is log-normally distributed and slightly depends on the spatial scale of analysis; on the contrary, pathological strips show pronounced tissue disorganization, characterized by local disarray significantly dependent on the spatial scale of analysis. A virtual sample generator is developed to link this multi-scale disarray analysis with the underlying cellular architecture. This approach allowed us to quantitatively assess tissue organization in terms of 3D myocyte angular dispersion and may pave the way for developing novel predictive models based on structural data at cellular resolution.
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Affiliation(s)
- Francesco Giardini
- Laboratory of Non-Linear Spectroscopy (LENS), University of Florence, Sesto Fiorentino, Italy
| | - Erica Lazzeri
- Laboratory of Non-Linear Spectroscopy (LENS), University of Florence, Sesto Fiorentino, Italy
| | - Giulia Vitale
- Division of Physiology, Department of Clinical and Experimental Medicine, University of Florence, Florence, Italy
| | - Cecilia Ferrantini
- Laboratory of Non-Linear Spectroscopy (LENS), University of Florence, Sesto Fiorentino, Italy.,Division of Physiology, Department of Clinical and Experimental Medicine, University of Florence, Florence, Italy
| | - Irene Costantini
- Laboratory of Non-Linear Spectroscopy (LENS), University of Florence, Sesto Fiorentino, Italy.,National Institute of Optics, National Research Council, University of Florence, Florence, Italy.,Department of Biology, University of Florence, Florence, Italy
| | - Francesco S Pavone
- Laboratory of Non-Linear Spectroscopy (LENS), University of Florence, Sesto Fiorentino, Italy.,National Institute of Optics, National Research Council, University of Florence, Florence, Italy.,Department of Physics, University of Florence, Florence, Italy
| | - Corrado Poggesi
- Division of Physiology, Department of Clinical and Experimental Medicine, University of Florence, Florence, Italy
| | - Leonardo Bocchi
- Laboratory of Non-Linear Spectroscopy (LENS), University of Florence, Sesto Fiorentino, Italy.,Department of Information Engineering, University of Florence, Florence, Italy
| | - Leonardo Sacconi
- Laboratory of Non-Linear Spectroscopy (LENS), University of Florence, Sesto Fiorentino, Italy.,National Institute of Optics, National Research Council, University of Florence, Florence, Italy.,Faculty of Medicine, Institute for Experimental Cardiovascular Medicine, University of Freiburg, Freiburg im Breisgau, Germany
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12
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Hopman LHGA, Mulder MJ, van der Laan AM, Demirkiran A, Bhagirath P, van Rossum AC, Allaart CP, Götte MJW. Impaired left atrial reservoir and conduit strain in patients with atrial fibrillation and extensive left atrial fibrosis. J Cardiovasc Magn Reson 2021; 23:131. [PMID: 34758820 PMCID: PMC8582184 DOI: 10.1186/s12968-021-00820-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 10/11/2021] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Atrial fibrillation (AF) is associated with profound structural and functional changes in the atria. In the present study, we investigated the association between left atrial (LA) phasic function and the extent of LA fibrosis using advanced cardiovascular magnetic resonance (CMR) imaging techniques, including 3-dimensional (3D) late gadolinium enhancement (LGE) and feature tracking. METHODS Patients with paroxysmal and persistent AF (n = 105) underwent CMR in sinus rhythm. LA global reservoir strain, conduit strain and contractile strain were derived from cine CMR images using CMR feature tracking. The extent of LA fibrosis was assessed from 3D LGE images. Healthy subjects underwent CMR and served as controls (n = 19). RESULTS Significantly lower LA reservoir strain, conduit strain and contractile strain were found in AF patients, as compared to healthy controls (- 15.9 ± 3.8% vs. - 21.1 ± 3.6% P < 0.001, - 8.7 ± 2.7% vs. - 12.6 ± 2.5% P < 0.001 and - 7.2 ± 2.3% vs. - 8.6 ± 2.2% P = 0.02, respectively). Patients with a high degree of LA fibrosis (dichotomized by the median value) had lower reservoir strain and conduit strain compared to patients with a low degree of LA fibrosis (- 15.0 ± 3.9% vs. - 16.9 ± 3.3%, P = 0.02 and - 7.9 ± 2.7% vs. - 9.5 ± 2.6%, P = 0.01, respectively). In contrast, no difference was found for LA contractile strain (- 7.1 ± 2.4% vs. - 7.4 ± 2.3%, P = 0.55). CONCLUSIONS Impaired LA reservoir and conduit strain are present in AF patients with extensive atrial fibrosis. Future studies are needed to examine the biologic nature of this association and possible therapeutic implications.
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Affiliation(s)
- Luuk H. G. A. Hopman
- Department of Cardiology, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam Cardiovascular Sciences, De Boelelaan 1118, 1081 HV Amsterdam, The Netherlands
| | - Mark J. Mulder
- Department of Cardiology, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam Cardiovascular Sciences, De Boelelaan 1118, 1081 HV Amsterdam, The Netherlands
| | - Anja M. van der Laan
- Department of Cardiology, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam Cardiovascular Sciences, De Boelelaan 1118, 1081 HV Amsterdam, The Netherlands
| | - Ahmet Demirkiran
- Department of Cardiology, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam Cardiovascular Sciences, De Boelelaan 1118, 1081 HV Amsterdam, The Netherlands
| | - Pranav Bhagirath
- Department of Cardiology, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam Cardiovascular Sciences, De Boelelaan 1118, 1081 HV Amsterdam, The Netherlands
| | - Albert C. van Rossum
- Department of Cardiology, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam Cardiovascular Sciences, De Boelelaan 1118, 1081 HV Amsterdam, The Netherlands
| | - Cornelis P. Allaart
- Department of Cardiology, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam Cardiovascular Sciences, De Boelelaan 1118, 1081 HV Amsterdam, The Netherlands
| | - Marco J. W. Götte
- Department of Cardiology, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam Cardiovascular Sciences, De Boelelaan 1118, 1081 HV Amsterdam, The Netherlands
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13
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Sánchez J, Trenor B, Saiz J, Dössel O, Loewe A. Fibrotic Remodeling during Persistent Atrial Fibrillation: In Silico Investigation of the Role of Calcium for Human Atrial Myofibroblast Electrophysiology. Cells 2021; 10:cells10112852. [PMID: 34831076 PMCID: PMC8616446 DOI: 10.3390/cells10112852] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 10/08/2021] [Accepted: 10/19/2021] [Indexed: 12/20/2022] Open
Abstract
During atrial fibrillation, cardiac tissue undergoes different remodeling processes at different scales from the molecular level to the tissue level. One central player that contributes to both electrical and structural remodeling is the myofibroblast. Based on recent experimental evidence on myofibroblasts' ability to contract, we extended a biophysical myofibroblast model with Ca2+ handling components and studied the effect on cellular and tissue electrophysiology. Using genetic algorithms, we fitted the myofibroblast model parameters to the existing in vitro data. In silico experiments showed that Ca2+ currents can explain the experimentally observed variability regarding the myofibroblast resting membrane potential. The presence of an L-type Ca2+ current can trigger automaticity in the myofibroblast with a cycle length of 799.9 ms. Myocyte action potentials were prolonged when coupled to myofibroblasts with Ca2+ handling machinery. Different spatial myofibroblast distribution patterns increased the vulnerable window to induce arrhythmia from 12 ms in non-fibrotic tissue to 22 ± 2.5 ms and altered the reentry dynamics. Our findings suggest that Ca2+ handling can considerably affect myofibroblast electrophysiology and alter the electrical propagation in atrial tissue composed of myocytes coupled with myofibroblasts. These findings can inform experimental validation experiments to further elucidate the role of myofibroblast Ca2+ handling in atrial arrhythmogenesis.
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Affiliation(s)
- Jorge Sánchez
- Institute of Biomedical Engineering, Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe, Germany; (O.D.); (A.L.)
- Correspondence:
| | - Beatriz Trenor
- Centro de Investigación e Innovación en Bioingeniería (Ci2B), Universitàt Politècnica de València, 46022 Valencia, Spain; (B.T.); (J.S.)
| | - Javier Saiz
- Centro de Investigación e Innovación en Bioingeniería (Ci2B), Universitàt Politècnica de València, 46022 Valencia, Spain; (B.T.); (J.S.)
| | - Olaf Dössel
- Institute of Biomedical Engineering, Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe, Germany; (O.D.); (A.L.)
| | - Axel Loewe
- Institute of Biomedical Engineering, Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe, Germany; (O.D.); (A.L.)
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14
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Lange M, Hirahara AM, Ranjan R, Stoddard GJ, Dosdall DJ. Atrial slow conduction develops and dynamically expands during premature stimulation in an animal model of persistent atrial fibrillation. PLoS One 2021; 16:e0258285. [PMID: 34618871 PMCID: PMC8496790 DOI: 10.1371/journal.pone.0258285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 09/24/2021] [Indexed: 11/18/2022] Open
Abstract
Slow conduction areas and conduction block in the atria are considered pro-arrhythmic conditions. Studies examining the size and distribution of slow conduction regions in the context of persistent atrial fibrillation (AF) may help to develop improved therapeutic strategies for patients with AF. In this work, we studied the differences of size and number in slow conduction areas between control and persistent AF goats and the influence of propagation direction on the development of these pathological conduction areas. Epicardial atrial electrical activations from the left atrial roof were optically mapped with physiological pacing cycle lengths and for the shortest captured cycle lengths. The recordings were converted to local activation times and conduction velocity measures. Regions with slow conduction velocity (less than [Formula: see text]) were identified. The size of the connected regions and the number of non-connected regions were counted for propagation from different orthogonal directions. We found that regions of slow conduction significantly increases in our 15 persistent AF goat recordings in response to premature stimulation (24.4±4.3% increase to 36.6±4.4%, p < 0.001). This increase is driven by an increase of size from (3.70±0.89[mm2] to 6.36±0.91[mm2], p = 0.014) for already existing regions and not by generation of new slow conduction regions (11.6±1.8 vs. 13±1.9, p = 0.242). In 12 control goat recordings, no increase from baseline pacing to premature pacing was found. Similarly, size of the slow conduction areas and the count did not change significantly in control animals.
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Affiliation(s)
- Matthias Lange
- Nora Eccles Harrison Cardiovasular Research and Training Institute, University of Utah, Salt Lake City, Utah, United States of America
| | - Annie M. Hirahara
- Nora Eccles Harrison Cardiovasular Research and Training Institute, University of Utah, Salt Lake City, Utah, United States of America
- Biomedical Engineering, University of Utah, Salt Lake City, Utah, United States of America
| | - Ravi Ranjan
- Nora Eccles Harrison Cardiovasular Research and Training Institute, University of Utah, Salt Lake City, Utah, United States of America
- Biomedical Engineering, University of Utah, Salt Lake City, Utah, United States of America
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Gregory J. Stoddard
- Division of Epidemiology, Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Derek J. Dosdall
- Nora Eccles Harrison Cardiovasular Research and Training Institute, University of Utah, Salt Lake City, Utah, United States of America
- Biomedical Engineering, University of Utah, Salt Lake City, Utah, United States of America
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
- Division of Cardiothoracic Surgery, Department of Surgery, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
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15
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Irakoze É, Jacquemet V. Multiparameter optimization of nonuniform passive diffusion properties for creating coarse-grained equivalent models of cardiac propagation. Comput Biol Med 2021; 138:104863. [PMID: 34562679 DOI: 10.1016/j.compbiomed.2021.104863] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 09/06/2021] [Accepted: 09/07/2021] [Indexed: 11/30/2022]
Abstract
The arrhythmogenic role of discrete cardiac propagation may be assessed by comparing discrete (fine-grained) and equivalent continuous (coarse-grained) models. We aim to develop an optimization algorithm for estimating the smooth conductivity field that best reproduces the diffusion properties of a given discrete model. Our algorithm iteratively adjusts local conductivity of the coarse-grained continuous model by simulating passive diffusion from white noise initial conditions during 3-10 ms and computing the root mean square error with respect to the discrete model. The coarse-grained conductivity field was interpolated from up to 300 evenly spaced control points. We derived an approximate formula for the gradient of the cost function that required (in two dimensions) only two additional simulations per iteration regardless of the number of estimated parameters. Conjugate gradient solver facilitated simultaneous optimization of multiple conductivity parameters. The method was tested in rectangular anisotropic tissues with uniform and nonuniform conductivity (slow regions with sinusoidal profile) and random diffuse fibrosis, as well as in a monolayer interconnected cable model of the left atrium with spatially-varying fibrosis density. Comparison of activation maps served as validation. The results showed that after convergence the errors in activation time were < 1 ms for rectangular geometries and 1-3 ms in the atrial model. Our approach based on the comparison of passive properties (<10 ms simulation) avoids performing active propagation simulations (>100 ms) at each iteration while reproducing activation maps, with possible applications to investigating the impact of microstructure on arrhythmias.
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Affiliation(s)
- Éric Irakoze
- Pharmacology and Physiology Department, Institute of Biomedical Engineering, Université de Montréal, Montreal, QC, H3T 1J4, Canada; Hôpital Du Sacré-Cœur de Montréal, Research Center, 5400 Boul. Gouin Ouest, Montreal, QC, H4J 1C5, Canada
| | - Vincent Jacquemet
- Pharmacology and Physiology Department, Institute of Biomedical Engineering, Université de Montréal, Montreal, QC, H3T 1J4, Canada; Hôpital Du Sacré-Cœur de Montréal, Research Center, 5400 Boul. Gouin Ouest, Montreal, QC, H4J 1C5, Canada.
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16
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Saliani A, Irakoze É, Jacquemet V. Simulation of diffuse and stringy fibrosis in a bilayer interconnected cable model of the left atrium. Europace 2021; 23:i169-i177. [PMID: 33751082 DOI: 10.1093/europace/euab001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 01/04/2021] [Indexed: 11/13/2022] Open
Abstract
AIMS The aim of this study is to design a computer model of the left atrium for investigating fibre-orientation-dependent microstructure such as stringy fibrosis. METHODS AND RESULTS We developed an approach for automatic construction of bilayer interconnected cable models from left atrial geometry and epi- and endocardial fibre orientation. The model consisted of two layers (epi- and endocardium) of longitudinal and transverse cables intertwined-like fabric threads, with a spatial discretization of 100 µm. Model validation was performed by comparison with cubic volumetric models in normal conditions. Then, diffuse (n = 2904), stringy (n = 3600), and mixed fibrosis patterns (n = 6840) were randomly generated by uncoupling longitudinal and transverse connections in the interconnected cable model. Fibrosis density was varied from 0% to 40% and mean stringy obstacle length from 0.1 to 2 mm. Total activation time, apparent anisotropy ratio, and local activation time jitter were computed during normal rhythm in each pattern. Non-linear regression formulas were identified for expressing measured propagation parameters as a function of fibrosis density and obstacle length (stringy and mixed patterns). Longer obstacles (even below tissue space constant) were independently associated with prolonged activation times, increased anisotropy, and local fluctuations in activation times. This effect was increased by endo-epicardial dissociation and mitigated when fibrosis was limited to the epicardium. CONCLUSION Interconnected cable models enable the study of microstructure in organ-size models despite limitations in the description of transmural structures.
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Affiliation(s)
- Ariane Saliani
- Department of Pharmacology and Physiology, Institute of Biomedical Engineering, Université de Montréal, Montréal, QC H3T 1J4, Canada.,Research Center, Hôpital du Sacré-Cœur de Montréal, 5400 boul. Gouin Ouest, Montréal, QC H4J 1C5, Canada
| | - Éric Irakoze
- Department of Pharmacology and Physiology, Institute of Biomedical Engineering, Université de Montréal, Montréal, QC H3T 1J4, Canada.,Research Center, Hôpital du Sacré-Cœur de Montréal, 5400 boul. Gouin Ouest, Montréal, QC H4J 1C5, Canada
| | - Vincent Jacquemet
- Department of Pharmacology and Physiology, Institute of Biomedical Engineering, Université de Montréal, Montréal, QC H3T 1J4, Canada.,Research Center, Hôpital du Sacré-Cœur de Montréal, 5400 boul. Gouin Ouest, Montréal, QC H4J 1C5, Canada
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17
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Schopp M, Dharmaprani D, Kuklik P, Quah J, Lahiri A, Tiver K, Meyer C, Willems S, McGavigan AD, Ganesan AN. Spatial concentration and distribution of phase singularities in human atrial fibrillation: Insights for the AF mechanism. J Arrhythm 2021; 37:922-930. [PMID: 34386118 PMCID: PMC8339121 DOI: 10.1002/joa3.12547] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 04/10/2021] [Accepted: 04/14/2021] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Atrial fibrillation (AF) is characterized by the repetitive regeneration of unstable rotational events, the pivot of which are known as phase singularities (PSs). The spatial concentration and distribution of PSs have not been systematically investigated using quantitative statistical approaches. OBJECTIVES We utilized a geospatial statistical approach to determine the presence of local spatial concentration and global clustering of PSs in biatrial human AF recordings. METHODS 64-electrode conventional basket (~5 min, n = 18 patients, persistent AF) recordings were studied. Phase maps were produced using a Hilbert-transform based approach. PSs were characterized spatially using the following approaches: (i) local "hotspots" of high phase singularity (PS) concentration using Getis-Ord Gi* (Z ≥ 1.96, P ≤ .05) and (ii) global spatial clustering using Moran's I (inverse distance matrix). RESULTS Episodes of AF were analyzed from basket catheter recordings (H: 41 epochs, 120 000 s, n = 18 patients). The Getis-Ord Gi* statistic showed local PS hotspots in 12/41 basket recordings. As a metric of spatial clustering, Moran's I showed an overall mean of 0.033 (95% CI: 0.0003-0.065), consistent with the notion of complete spatial randomness. CONCLUSION Using a systematic, quantitative geospatial statistical approach, evidence for the existence of spatial concentrations ("hotspots") of PSs were detectable in human AF, along with evidence of spatial clustering. Geospatial statistical approaches offer a new approach to map and ablate PS clusters using substrate-based approaches.
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Affiliation(s)
- Madeline Schopp
- College of Science and EngineeringFlinders University of South AustraliaAdelaideSAAustralia
| | - Dhani Dharmaprani
- College of Science and EngineeringFlinders University of South AustraliaAdelaideSAAustralia
- College of Medicine and Public HealthFlinders University of South AustraliaAdelaideSAAustralia
| | - Pawel Kuklik
- Department of CardiologyUniversity Medical CentreHamburgGermany
| | - Jing Quah
- College of Medicine and Public HealthFlinders University of South AustraliaAdelaideSAAustralia
- Department of Cardiovascular MedicineFlinders Medical CentreAdelaideSAAustralia
| | - Anandaroop Lahiri
- Department of Cardiovascular MedicineFlinders Medical CentreAdelaideSAAustralia
| | - Kathryn Tiver
- College of Medicine and Public HealthFlinders University of South AustraliaAdelaideSAAustralia
- Department of Cardiovascular MedicineFlinders Medical CentreAdelaideSAAustralia
| | - Christian Meyer
- Department of CardiologyUniversity Medical CentreHamburgGermany
| | - Stephan Willems
- Department of CardiologyUniversity Medical CentreHamburgGermany
| | - Andrew D. McGavigan
- Department of Cardiovascular MedicineFlinders Medical CentreAdelaideSAAustralia
| | - Anand N. Ganesan
- College of Medicine and Public HealthFlinders University of South AustraliaAdelaideSAAustralia
- Department of Cardiovascular MedicineFlinders Medical CentreAdelaideSAAustralia
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18
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Bai J, Lu Y, Zhu Y, Wang H, Yin D, Zhang H, Franco D, Zhao J. Understanding PITX2-Dependent Atrial Fibrillation Mechanisms through Computational Models. Int J Mol Sci 2021; 22:7681. [PMID: 34299303 PMCID: PMC8307824 DOI: 10.3390/ijms22147681] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 07/14/2021] [Accepted: 07/16/2021] [Indexed: 01/11/2023] Open
Abstract
Atrial fibrillation (AF) is a common arrhythmia. Better prevention and treatment of AF are needed to reduce AF-associated morbidity and mortality. Several major mechanisms cause AF in patients, including genetic predispositions to AF development. Genome-wide association studies have identified a number of genetic variants in association with AF populations, with the strongest hits clustering on chromosome 4q25, close to the gene for the homeobox transcription PITX2. Because of the inherent complexity of the human heart, experimental and basic research is insufficient for understanding the functional impacts of PITX2 variants on AF. Linking PITX2 properties to ion channels, cells, tissues, atriums and the whole heart, computational models provide a supplementary tool for achieving a quantitative understanding of the functional role of PITX2 in remodelling atrial structure and function to predispose to AF. It is hoped that computational approaches incorporating all we know about PITX2-related structural and electrical remodelling would provide better understanding into its proarrhythmic effects leading to development of improved anti-AF therapies. In the present review, we discuss advances in atrial modelling and focus on the mechanistic links between PITX2 and AF. Challenges in applying models for improving patient health are described, as well as a summary of future perspectives.
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Affiliation(s)
- Jieyun Bai
- College of Information Science and Technology, Jinan University, Guangzhou 510632, China; (Y.L.); (Y.Z.)
- Auckland Bioengineering Institute, University of Auckland, Auckland 1010, New Zealand
| | - Yaosheng Lu
- College of Information Science and Technology, Jinan University, Guangzhou 510632, China; (Y.L.); (Y.Z.)
| | - Yijie Zhu
- College of Information Science and Technology, Jinan University, Guangzhou 510632, China; (Y.L.); (Y.Z.)
| | - Huijin Wang
- College of Information Science and Technology, Jinan University, Guangzhou 510632, China; (Y.L.); (Y.Z.)
| | - Dechun Yin
- Department of Cardiology, First Affiliated Hospital of Harbin Medical University, Harbin 150000, China;
| | - Henggui Zhang
- Biological Physics Group, School of Physics & Astronomy, The University of Manchester, Manchester M13 9PL, UK;
| | - Diego Franco
- Department of Experimental Biology, University of Jaen, 23071 Jaen, Spain;
| | - Jichao Zhao
- Auckland Bioengineering Institute, University of Auckland, Auckland 1010, New Zealand
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19
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Sánchez J, Luongo G, Nothstein M, Unger LA, Saiz J, Trenor B, Luik A, Dössel O, Loewe A. Using Machine Learning to Characterize Atrial Fibrotic Substrate From Intracardiac Signals With a Hybrid in silico and in vivo Dataset. Front Physiol 2021; 12:699291. [PMID: 34290623 PMCID: PMC8287829 DOI: 10.3389/fphys.2021.699291] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 06/08/2021] [Indexed: 11/15/2022] Open
Abstract
In patients with atrial fibrillation, intracardiac electrogram signal amplitude is known to decrease with increased structural tissue remodeling, referred to as fibrosis. In addition to the isolation of the pulmonary veins, fibrotic sites are considered a suitable target for catheter ablation. However, it remains an open challenge to find fibrotic areas and to differentiate their density and transmurality. This study aims to identify the volume fraction and transmurality of fibrosis in the atrial substrate. Simulated cardiac electrograms, combined with a generalized model of clinical noise, reproduce clinically measured signals. Our hybrid dataset approach combines in silico and clinical electrograms to train a decision tree classifier to characterize the fibrotic atrial substrate. This approach captures different in vivo dynamics of the electrical propagation reflected on healthy electrogram morphology and synergistically combines it with synthetic fibrotic electrograms from in silico experiments. The machine learning algorithm was tested on five patients and compared against clinical voltage maps as a proof of concept, distinguishing non-fibrotic from fibrotic tissue and characterizing the patient's fibrotic tissue in terms of density and transmurality. The proposed approach can be used to overcome a single voltage cut-off value to identify fibrotic tissue and guide ablation targeting fibrotic areas.
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Affiliation(s)
- Jorge Sánchez
- Institute of Biomedical Engineering, Karlsruhe Institute for Technology, Karlsruhe, Germany
- Centro de Investigación e Innovación en Bioingeniería (Ci2B), Universitàt Politècnica de València, Valencia, Spain
| | - Giorgio Luongo
- Institute of Biomedical Engineering, Karlsruhe Institute for Technology, Karlsruhe, Germany
| | - Mark Nothstein
- Institute of Biomedical Engineering, Karlsruhe Institute for Technology, Karlsruhe, Germany
| | - Laura A. Unger
- Institute of Biomedical Engineering, Karlsruhe Institute for Technology, Karlsruhe, Germany
| | - Javier Saiz
- Centro de Investigación e Innovación en Bioingeniería (Ci2B), Universitàt Politècnica de València, Valencia, Spain
| | - Beatriz Trenor
- Centro de Investigación e Innovación en Bioingeniería (Ci2B), Universitàt Politècnica de València, Valencia, Spain
| | - Armin Luik
- Medizinische Klinik IV, Städtisches Klinikum Karlsruhe, Karlsruhe, Germany
| | - Olaf Dössel
- Institute of Biomedical Engineering, Karlsruhe Institute for Technology, Karlsruhe, Germany
| | - Axel Loewe
- Institute of Biomedical Engineering, Karlsruhe Institute for Technology, Karlsruhe, Germany
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20
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Xintarakou A, Tzeis S, Psarras S, Asvestas D, Vardas P. Atrial fibrosis as a dominant factor for the development of atrial fibrillation: facts and gaps. Europace 2021; 22:342-351. [PMID: 31998939 DOI: 10.1093/europace/euaa009] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 01/03/2020] [Indexed: 01/08/2023] Open
Abstract
Atrial fibrillation (AF), the most commonly diagnosed arrhythmia, affects a notable percentage of the population and constitutes a major risk factor for thromboembolic events and other heart-related conditions. Fibrosis plays an important role in the onset and perpetuation of AF through structural and electrical remodelling processes. Multiple molecular pathways are involved in atrial substrate modification and the subsequent maintenance of AF. In this review, we aim to recapitulate underlying molecular pathways leading to atrial fibrosis and to indicate existing gaps in the complex interplay of atrial fibrosis and AF.
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Affiliation(s)
| | - Stylianos Tzeis
- Cardiology Department, Mitera General Hospital, Hygeia Group, Athens, Greece
| | - Stelios Psarras
- Center of Basic Research, Biomedical Research Foundation Academy of Athens, Greece
| | - Dimitrios Asvestas
- Cardiology Department, Mitera General Hospital, Hygeia Group, Athens, Greece
| | - Panos Vardas
- Heart Sector, Hygeia Hospitals Group, 5, Erithrou Stavrou, Marousi, Athens 15123, Greece
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21
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Heijman J, Sutanto H, Crijns HJGM, Nattel S, Trayanova NA. Computational models of atrial fibrillation: achievements, challenges, and perspectives for improving clinical care. Cardiovasc Res 2021; 117:1682-1699. [PMID: 33890620 PMCID: PMC8208751 DOI: 10.1093/cvr/cvab138] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Indexed: 12/11/2022] Open
Abstract
Despite significant advances in its detection, understanding and management, atrial fibrillation (AF) remains a highly prevalent cardiac arrhythmia with a major impact on morbidity and mortality of millions of patients. AF results from complex, dynamic interactions between risk factors and comorbidities that induce diverse atrial remodelling processes. Atrial remodelling increases AF vulnerability and persistence, while promoting disease progression. The variability in presentation and wide range of mechanisms involved in initiation, maintenance and progression of AF, as well as its associated adverse outcomes, make the early identification of causal factors modifiable with therapeutic interventions challenging, likely contributing to suboptimal efficacy of current AF management. Computational modelling facilitates the multilevel integration of multiple datasets and offers new opportunities for mechanistic understanding, risk prediction and personalized therapy. Mathematical simulations of cardiac electrophysiology have been around for 60 years and are being increasingly used to improve our understanding of AF mechanisms and guide AF therapy. This narrative review focuses on the emerging and future applications of computational modelling in AF management. We summarize clinical challenges that may benefit from computational modelling, provide an overview of the different in silico approaches that are available together with their notable achievements, and discuss the major limitations that hinder the routine clinical application of these approaches. Finally, future perspectives are addressed. With the rapid progress in electronic technologies including computing, clinical applications of computational modelling are advancing rapidly. We expect that their application will progressively increase in prominence, especially if their added value can be demonstrated in clinical trials.
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Affiliation(s)
- Jordi Heijman
- Department of Cardiology, Cardiovascular Research Institute Maastricht, Faculty of Health, Medicine, and Life Sciences, Maastricht University, PO Box 616, 6200 MD Maastricht, The Netherlands
| | - Henry Sutanto
- Department of Cardiology, Cardiovascular Research Institute Maastricht, Faculty of Health, Medicine, and Life Sciences, Maastricht University, PO Box 616, 6200 MD Maastricht, The Netherlands
| | - Harry J G M Crijns
- Department of Cardiology, Cardiovascular Research Institute Maastricht, Faculty of Health, Medicine, and Life Sciences, Maastricht University, PO Box 616, 6200 MD Maastricht, The Netherlands
| | - Stanley Nattel
- Department of Medicine, Montreal Heart Institute and Université de Montréal, Montreal, Canada
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Canada
- Institute of Pharmacology, West German Heart and Vascular Center, Faculty of Medicine, University Duisburg-Essen, Duisburg, Germany
- IHU Liryc and Fondation Bordeaux Université, Bordeaux, France
| | - Natalia A Trayanova
- Alliance for Cardiovascular Diagnostic and Treatment Innovation, and Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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22
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Imaging Techniques for the Study of Fibrosis in Atrial Fibrillation Ablation: From Molecular Mechanisms to Therapeutical Perspectives. J Clin Med 2021; 10:jcm10112277. [PMID: 34073969 PMCID: PMC8197293 DOI: 10.3390/jcm10112277] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 05/05/2021] [Accepted: 05/20/2021] [Indexed: 12/24/2022] Open
Abstract
Atrial fibrillation (AF) is the most prevalent form of cardiac arrhythmia. It is often related to diverse pathological conditions affecting the atria and leading to remodeling processes including collagen accumulation, fatty infiltration, and amyloid deposition. All these events generate atrial fibrosis, which contribute to beget AF. In this scenario, cardiac imaging appears as a promising noninvasive tool for monitoring the presence and degree of LA fibrosis and remodeling. The aim of this review is to comprehensively examine the bench mechanisms of atrial fibrosis moving, then to describe the principal imaging techniques that characterize it, such as cardiac magnetic resonance (CMR) and multidetector cardiac computed tomography (MDCT), in order to tailor atrial fibrillation ablation to each individual.
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23
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Sohns C, Marrouche NF. Atrial fibrillation and cardiac fibrosis. Eur Heart J 2021; 41:1123-1131. [PMID: 31713590 DOI: 10.1093/eurheartj/ehz786] [Citation(s) in RCA: 126] [Impact Index Per Article: 42.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 09/30/2019] [Accepted: 10/23/2019] [Indexed: 12/25/2022] Open
Abstract
The understanding of atrial fibrillation (AF) evolved from a sole rhythm disturbance towards the complex concept of a cardiomyopathy based on arrhythmia substrates. There is evidence that atrial fibrosis can be visualized using late gadolinium enhancement cardiac magnetic resonance imaging and that it is a powerful predictor for the outcome of AF interventions. However, a strategy of an individual and fibrosis guided management of AF looks promising but results from prospective multicentre trials are pending. This review gives an overview about the relationship between cardiac fibrosis and AF focusing on translational aspects, clinical observations, and fibrosis imaging to emphasize the concept of personalized paths in AF management taking into account the individual amount and distribution of fibrosis.
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Affiliation(s)
- Christian Sohns
- Clinic for Electrophysiology, Herz- und Diabeteszentrum NRW, Ruhr-Universität Bochum, Bad Oeynhausen, Germany
| | - Nassir F Marrouche
- Cardiac Electrophysiology, Tulane University School of Medicine, 1430 Tulane Avenue, Box 8548, New Orleans, LA 70112, USA
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24
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Peigh G, Shah SJ, Patel RB. Left Atrial Myopathy in Atrial Fibrillation and Heart Failure: Clinical Implications, Mechanisms, and Therapeutic Targets. Curr Heart Fail Rep 2021; 18:85-98. [PMID: 33864224 DOI: 10.1007/s11897-021-00510-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/22/2021] [Indexed: 12/26/2022]
Abstract
PURPOSE OF REVIEW This review discusses the mechanisms, clinical implications, and treatments of left atrial (LA) myopathy in comorbid atrial fibrillation (AF) and heart failure (HF) across the spectrum of ejection fraction. RECENT FINDINGS AF and HF are highly comorbid conditions. Left atrial (LA) myopathy, characterized by impairments in LA structure, function, or electrical conduction, plays a fundamental role in the development of both AF and HF with preserved ejection fraction (AF-HFpEF) along with AF and HF with reduced ejection fraction (AF-HFrEF). While the nature of LA myopathy in AF-HFpEF is unique from that of AF-HFrEF, LA myopathy also leads to progression of both of these conditions. There may be a vulnerable cohort of AF-HF patients who have a disproportionate degree of LA myopathy compared with left ventricular (LV) dysfunction. Further investigations are required to identify therapies to improve LA function in this cohort.
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Affiliation(s)
- Graham Peigh
- Division of Cardiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Sanjiv J Shah
- Division of Cardiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Ravi B Patel
- Division of Cardiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA. .,Division of Cardiology, Northwestern Memorial Hospital, 676 N St. Clair Suite 600, Chicago, IL, 60611, USA.
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25
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Abstract
AF is the most common arrhythmia in clinical practice. In addition to the severe effect on quality of life, patients with AF are at higher risk of stroke and mortality. Recent studies have suggested that atrial and ventricular substrate play a major role in the development and maintenance of AF. Cardiac MRI has emerged as a viable tool for interrogating the underlying substrate in AF patients. Its advantage includes localisation and quantification of structural remodelling. Cardiac MRI of the atrial substrate is not only a tool for management and treatment of arrhythmia, but also to individualise the prevention of stroke and major cardiovascular events. This article provides an overview of atrial imaging using cardiac MRI and its clinical implications in the AF population.
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Affiliation(s)
- Yan Zhao
- Tulane Research Innovation for Arrhythmia Discoveries (TRIAD), Heart and Vascular Institute, Tulane University School of Medicine, LA, US
| | - Lilas Dagher
- Tulane Research Innovation for Arrhythmia Discoveries (TRIAD), Heart and Vascular Institute, Tulane University School of Medicine, LA, US
| | - Chao Huang
- Tulane Research Innovation for Arrhythmia Discoveries (TRIAD), Heart and Vascular Institute, Tulane University School of Medicine, LA, US
| | - Peter Miller
- Tulane Research Innovation for Arrhythmia Discoveries (TRIAD), Heart and Vascular Institute, Tulane University School of Medicine, LA, US
| | - Nassir F Marrouche
- Tulane Research Innovation for Arrhythmia Discoveries (TRIAD), Heart and Vascular Institute, Tulane University School of Medicine, LA, US
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26
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Bifulco SF, Akoum N, Boyle PM. Translational applications of computational modelling for patients with cardiac arrhythmias. Heart 2020; 107:heartjnl-2020-316854. [PMID: 33303478 PMCID: PMC10896425 DOI: 10.1136/heartjnl-2020-316854] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Revised: 11/13/2020] [Accepted: 11/19/2020] [Indexed: 11/04/2022] Open
Abstract
Cardiac arrhythmia is associated with high morbidity, and its underlying mechanisms are poorly understood. Computational modelling and simulation approaches have the potential to improve standard-of-care therapy for these disorders, offering deeper understanding of complex disease processes and sophisticated translational tools for planning clinical procedures. This review provides a clinician-friendly summary of recent advancements in computational cardiology. Organ-scale models automatically generated from clinical-grade imaging data are used to custom tailor our understanding of arrhythmia drivers, estimate future arrhythmogenic risk and personalise treatment plans. Recent mechanistic insights derived from atrial and ventricular arrhythmia simulations are highlighted, and the potential avenues to patient care (eg, by revealing new antiarrhythmic drug targets) are covered. Computational approaches geared towards improving outcomes in resynchronisation therapy have used simulations to elucidate optimal patient selection and lead location. Technology to personalise catheter ablation procedures are also covered, specifically preliminary outcomes form early-stage or pilot clinical studies. To conclude, future developments in computational cardiology are discussed, including improving the representation of patient-specific fibre orientations and fibrotic remodelling characterisation and how these might improve understanding of arrhythmia mechanisms and provide transformative tools for patient-specific therapy.
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Affiliation(s)
- Savannah F Bifulco
- Department of Bioengineering, University of Washington, Seattle, Washington, USA
| | - Nazem Akoum
- Department of Cardiology, University of Washington, Seattle, Washington, USA
| | - Patrick M Boyle
- Department of Bioengineering, University of Washington, Seattle, Washington, USA
- Center for Cardiovascular Biology, University of Washington, Seattle, WA, USA
- Institute for Stem Cell & Regenerative Medicine, University of Washington, Seattle, WA, USA
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27
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Ho G, Lin AY, Krummen DE. Linking Electrical Drivers With Atrial Cardiomyopathy for the Targeted Treatment of Atrial Fibrillation. Front Physiol 2020; 11:570740. [PMID: 33281614 PMCID: PMC7689158 DOI: 10.3389/fphys.2020.570740] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 09/22/2020] [Indexed: 12/19/2022] Open
Abstract
The relationship between atrial fibrillation (AF) and underlying functional and structural abnormalities has received substantial attention in the research literature over the past decade. Significant progress has been made in identifying these changes using non-invasive imaging, voltage mapping, and electrical recordings. Advances in computed tomography and cardiac magnetic resonance imaging can now provide insight regarding the presence and extent of cardiac fibrosis. Additionally, multiple technologies able to identify electrical targets during AF have emerged. However, an organized strategy to employ these resources in the targeted treatment of AF remains elusive. In this work, we will discuss the basis for mechanistic importance of atrial fibrosis and scar as potential sites promoting AF and emerging technologies to identify and target these structural and functional substrates in the electrophysiology laboratory. We also propose an approach to the use of such technologies to serve as a basis for ongoing work in the field.
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Affiliation(s)
- Gordon Ho
- Division of Cardiology, Department of Medicine, University of California, San Diego, San Diego, CA, United States
- Division of Cardiology, Veterans Affairs San Diego Medical Center, San Diego, CA, United States
| | - Andrew Y. Lin
- Division of Cardiology, Department of Medicine, University of California, San Diego, San Diego, CA, United States
- Division of Cardiology, Veterans Affairs San Diego Medical Center, San Diego, CA, United States
| | - David E. Krummen
- Division of Cardiology, Department of Medicine, University of California, San Diego, San Diego, CA, United States
- Division of Cardiology, Veterans Affairs San Diego Medical Center, San Diego, CA, United States
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28
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Mikhailov AV, Kalyanasundaram A, Li N, Scott SS, Artiga EJ, Subr MM, Zhao J, Hansen BJ, Hummel JD, Fedorov VV. Comprehensive evaluation of electrophysiological and 3D structural features of human atrial myocardium with insights on atrial fibrillation maintenance mechanisms. J Mol Cell Cardiol 2020; 151:56-71. [PMID: 33130148 DOI: 10.1016/j.yjmcc.2020.10.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 10/22/2020] [Accepted: 10/23/2020] [Indexed: 12/14/2022]
Abstract
Atrial fibrillation (AF) occurrence and maintenance is associated with progressive remodeling of electrophysiological (repolarization and conduction) and 3D structural (fibrosis, fiber orientations, and wall thickness) features of the human atria. Significant diversity in AF etiology leads to heterogeneous arrhythmogenic electrophysiological and structural substrates within the 3D structure of the human atria. Since current clinical methods have yet to fully resolve the patient-specific arrhythmogenic substrates, mechanism-based AF treatments remain underdeveloped. Here, we review current knowledge from in-vivo, ex-vivo, and in-vitro human heart studies, and discuss how these studies may provide new insights on the synergy of atrial electrophysiological and 3D structural features in AF maintenance. In-vitro studies on surgically acquired human atrial samples provide a great opportunity to study a wide spectrum of AF pathology, including functional changes in single-cell action potentials, ion channels, and gene/protein expression. However, limited size of the samples prevents evaluation of heterogeneous AF substrates and reentrant mechanisms. In contrast, coronary-perfused ex-vivo human hearts can be studied with state-of-the-art functional and structural technologies, such as high-resolution near-infrared optical mapping and contrast-enhanced MRI. These imaging modalities can resolve atrial arrhythmogenic substrates and their role in reentrant mechanisms maintaining AF and validate clinical approaches. Nonetheless, longitudinal studies are not feasible in explanted human hearts. As no approach is perfect, we suggest that combining the strengths of direct human atrial studies with high fidelity approaches available in the laboratory and in realistic patient-specific computer models would elucidate deeper knowledge of AF mechanisms. We propose that a comprehensive translational pipeline from ex-vivo human heart studies to longitudinal clinically relevant AF animal studies and finally to clinical trials is necessary to identify patient-specific arrhythmogenic substrates and develop novel AF treatments.
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Affiliation(s)
- Aleksei V Mikhailov
- Department of Physiology & Cell Biology, Bob and Corrine Frick Center for Heart Failure and Arrhythmia, The Ohio State University Wexner Medical Center, Columbus, OH, USA; Arrhythmology Research Department, Almazov National Medical Research Centre, Saint-Petersburg, Russia
| | - Anuradha Kalyanasundaram
- Department of Physiology & Cell Biology, Bob and Corrine Frick Center for Heart Failure and Arrhythmia, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Ning Li
- Department of Physiology & Cell Biology, Bob and Corrine Frick Center for Heart Failure and Arrhythmia, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Shane S Scott
- Department of Physiology & Cell Biology, Bob and Corrine Frick Center for Heart Failure and Arrhythmia, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Esthela J Artiga
- Department of Physiology & Cell Biology, Bob and Corrine Frick Center for Heart Failure and Arrhythmia, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Megan M Subr
- Department of Physiology & Cell Biology, Bob and Corrine Frick Center for Heart Failure and Arrhythmia, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Jichao Zhao
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Brian J Hansen
- Department of Physiology & Cell Biology, Bob and Corrine Frick Center for Heart Failure and Arrhythmia, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - John D Hummel
- Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA; Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Vadim V Fedorov
- Department of Physiology & Cell Biology, Bob and Corrine Frick Center for Heart Failure and Arrhythmia, The Ohio State University Wexner Medical Center, Columbus, OH, USA; Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA.
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29
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Blomström-Lundqvist C, Marrouche N, Connolly S, Corp Dit Genti V, Wieloch M, Koren A, Hohnloser SH. Efficacy and safety of dronedarone by atrial fibrillation history duration: Insights from the ATHENA study. Clin Cardiol 2020; 43:1469-1477. [PMID: 33080088 PMCID: PMC7724236 DOI: 10.1002/clc.23463] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 08/11/2020] [Accepted: 08/24/2020] [Indexed: 11/22/2022] Open
Abstract
Background Atrial fibrillation/atrial flutter (AF/AFL) burden increases with increasing duration of AF/AFL history. Hypothesis Outcomes with dronedarone may also be impacted by duration of AF/AFL history. Methods In this post hoc analysis of ATHENA, efficacy and safety of dronedarone vs placebo were assessed in groups categorized by time from first known AF/AFL episode to randomization (ie, duration of AF/AFL history): <3 months (short), 3 to <24 months (intermediate), and ≥ 24 months (long). Results Of 2859 patients with data on duration of AF/AFL history, 45.3%, 29.6%, and 25.1% had short, intermediate, and long histories, respectively. Patients in the long history group had the highest prevalence of structural heart disease and were more likely to be in AF/AFL at baseline. Placebo‐treated patients in the long history group also had the highest incidence of AF/AFL recurrence and cardiovascular (CV) hospitalization during the study. The risk of first CV hospitalization/death from any cause was lower with dronedarone vs placebo in patients with short (hazard ratio, 0.79 [95% confidence interval: 0.65‐0.96]) and intermediate (0.72 [0.56‐0.92]) histories; a trend favoring dronedarone was also observed in patients with long history (0.84 [0.66‐1.07]). A similar pattern was observed for first AF/AFL recurrence. No new drug‐related safety issues were identified. Conclusions Patients with long AF/AFL history had the highest burden of AF/AFL at baseline and during the study. Dronedarone significantly improved efficacy vs placebo in patients with short and intermediate AF/AFL histories. While exploratory, these results support the potential value in initiating rhythm control treatment early in patients with AF/AFL.
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Affiliation(s)
| | - Nassir Marrouche
- Section of Cardiology, Tulane University Heart and Vascular Institute, New Orleans, Louisiana, USA
| | | | | | - Mattias Wieloch
- Sanofi-Aventis, Paris, France.,Department of Coagulation Disorders, Skåne University Hospital, Lund University, Malmö, Sweden
| | - Andrew Koren
- Sanofi, Bridgewater, New Jersey, at the time of the study, USA
| | - Stefan H Hohnloser
- Department of Cardiology, Division of Clinical Electrophysiology, J. W. Goethe University, Frankfurt, Germany
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30
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Hansen BJ, Zhao J, Helfrich KM, Li N, Iancau A, Zolotarev AM, Zakharkin SO, Kalyanasundaram A, Subr M, Dastagir N, Sharma R, Artiga EJ, Salgia N, Houmsse MM, Kahaly O, Janssen PML, Mohler PJ, Mokadam NA, Whitson BA, Afzal MR, Simonetti OP, Hummel JD, Fedorov VV. Unmasking Arrhythmogenic Hubs of Reentry Driving Persistent Atrial Fibrillation for Patient-Specific Treatment. J Am Heart Assoc 2020; 9:e017789. [PMID: 33006292 PMCID: PMC7792422 DOI: 10.1161/jaha.120.017789] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Background Atrial fibrillation (AF) driver mechanisms are obscured to clinical multielectrode mapping approaches that provide partial, surface‐only visualization of unstable 3‐dimensional atrial conduction. We hypothesized that transient modulation of refractoriness by pharmacologic challenge during multielectrode mapping improves visualization of hidden paths of reentrant AF drivers for targeted ablation. Methods and Results Pharmacologic challenge with adenosine was tested in ex vivo human hearts with a history of AF and cardiac diseases by multielectrode and high‐resolution subsurface near‐infrared optical mapping, integrated with 3‐dimensional structural imaging and heart‐specific computational simulations. Adenosine challenge was also studied on acutely terminated AF drivers in 10 patients with persistent AF. Ex vivo, adenosine stabilized reentrant driver paths within arrhythmogenic fibrotic hubs and improved visualization of reentrant paths, previously seen as focal or unstable breakthrough activation pattern, for targeted AF ablation. Computational simulations suggested that shortening of atrial refractoriness by adenosine may (1) improve driver stability by annihilating spatially unstable functional blocks and tightening reentrant circuits around fibrotic substrates, thus unmasking the common reentrant path; and (2) destabilize already stable reentrant drivers along fibrotic substrates by accelerating competing fibrillatory wavelets or secondary drivers. In patients with persistent AF, adenosine challenge unmasked hidden common reentry paths (9/15 AF drivers, 41±26% to 68±25% visualization), but worsened visualization of previously visible reentry paths (6/15, 74±14% to 34±12%). AF driver ablation led to acute termination of AF. Conclusions Our ex vivo to in vivo human translational study suggests that transiently altering atrial refractoriness can stabilize reentrant paths and unmask arrhythmogenic hubs to guide targeted AF driver ablation treatment.
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Affiliation(s)
- Brian J Hansen
- Department of Physiology & Cell Biology and Frick Center for Heart Failure and Arrhythmia The Ohio State University Wexner Medical Center Columbus OH.,Davis Heart & Lung Research InstituteThe Ohio State University Wexner Medical Center Columbus OH
| | | | - Katelynn M Helfrich
- Department of Physiology & Cell Biology and Frick Center for Heart Failure and Arrhythmia The Ohio State University Wexner Medical Center Columbus OH.,Davis Heart & Lung Research InstituteThe Ohio State University Wexner Medical Center Columbus OH
| | - Ning Li
- Department of Physiology & Cell Biology and Frick Center for Heart Failure and Arrhythmia The Ohio State University Wexner Medical Center Columbus OH.,Davis Heart & Lung Research InstituteThe Ohio State University Wexner Medical Center Columbus OH
| | - Alexander Iancau
- Department of Physiology & Cell Biology and Frick Center for Heart Failure and Arrhythmia The Ohio State University Wexner Medical Center Columbus OH
| | - Alexander M Zolotarev
- Department of Physiology & Cell Biology and Frick Center for Heart Failure and Arrhythmia The Ohio State University Wexner Medical Center Columbus OH.,Skolkovo Institute of Science and Technology Moscow Russia
| | - Stanislav O Zakharkin
- Department of Physiology & Cell Biology and Frick Center for Heart Failure and Arrhythmia The Ohio State University Wexner Medical Center Columbus OH
| | - Anuradha Kalyanasundaram
- Department of Physiology & Cell Biology and Frick Center for Heart Failure and Arrhythmia The Ohio State University Wexner Medical Center Columbus OH.,Davis Heart & Lung Research InstituteThe Ohio State University Wexner Medical Center Columbus OH
| | - Megan Subr
- Department of Physiology & Cell Biology and Frick Center for Heart Failure and Arrhythmia The Ohio State University Wexner Medical Center Columbus OH
| | | | | | - Esthela J Artiga
- Department of Physiology & Cell Biology and Frick Center for Heart Failure and Arrhythmia The Ohio State University Wexner Medical Center Columbus OH.,Davis Heart & Lung Research InstituteThe Ohio State University Wexner Medical Center Columbus OH
| | - Nicholas Salgia
- Department of Physiology & Cell Biology and Frick Center for Heart Failure and Arrhythmia The Ohio State University Wexner Medical Center Columbus OH
| | - Mustafa M Houmsse
- Department of Physiology & Cell Biology and Frick Center for Heart Failure and Arrhythmia The Ohio State University Wexner Medical Center Columbus OH
| | - Omar Kahaly
- Davis Heart & Lung Research InstituteThe Ohio State University Wexner Medical Center Columbus OH.,Department of Internal Medicine The Ohio State University Wexner Medical Center Columbus OH
| | - Paul M L Janssen
- Department of Physiology & Cell Biology and Frick Center for Heart Failure and Arrhythmia The Ohio State University Wexner Medical Center Columbus OH.,Davis Heart & Lung Research InstituteThe Ohio State University Wexner Medical Center Columbus OH
| | - Peter J Mohler
- Department of Physiology & Cell Biology and Frick Center for Heart Failure and Arrhythmia The Ohio State University Wexner Medical Center Columbus OH.,Davis Heart & Lung Research InstituteThe Ohio State University Wexner Medical Center Columbus OH
| | - Nahush A Mokadam
- Davis Heart & Lung Research InstituteThe Ohio State University Wexner Medical Center Columbus OH.,Division of Cardiac Surgery The Ohio State University Wexner Medical Center Columbus OH
| | - Bryan A Whitson
- Davis Heart & Lung Research InstituteThe Ohio State University Wexner Medical Center Columbus OH.,Division of Cardiac Surgery The Ohio State University Wexner Medical Center Columbus OH
| | - Muhammad R Afzal
- Davis Heart & Lung Research InstituteThe Ohio State University Wexner Medical Center Columbus OH.,Department of Internal Medicine The Ohio State University Wexner Medical Center Columbus OH
| | - Orlando P Simonetti
- Davis Heart & Lung Research InstituteThe Ohio State University Wexner Medical Center Columbus OH.,Department of Biomedical Engineering The Ohio State University Wexner Medical Center Columbus OH
| | - John D Hummel
- Davis Heart & Lung Research InstituteThe Ohio State University Wexner Medical Center Columbus OH.,Department of Internal Medicine The Ohio State University Wexner Medical Center Columbus OH
| | - Vadim V Fedorov
- Department of Physiology & Cell Biology and Frick Center for Heart Failure and Arrhythmia The Ohio State University Wexner Medical Center Columbus OH.,Davis Heart & Lung Research InstituteThe Ohio State University Wexner Medical Center Columbus OH
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Transsulfuration metabolites and the association with incident atrial fibrillation – An observational cohort study among Norwegian patients with stable angina pectoris. Int J Cardiol 2020; 317:75-80. [DOI: 10.1016/j.ijcard.2020.05.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 04/16/2020] [Accepted: 05/04/2020] [Indexed: 11/19/2022]
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Zolotarev AM, Hansen BJ, Ivanova EA, Helfrich KM, Li N, Janssen PML, Mohler PJ, Mokadam NA, Whitson BA, Fedorov MV, Hummel JD, Dylov DV, Fedorov VV. Optical Mapping-Validated Machine Learning Improves Atrial Fibrillation Driver Detection by Multi-Electrode Mapping. Circ Arrhythm Electrophysiol 2020; 13:e008249. [PMID: 32921129 DOI: 10.1161/circep.119.008249] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Atrial fibrillation (AF) can be maintained by localized intramural reentrant drivers. However, AF driver detection by clinical surface-only multielectrode mapping (MEM) has relied on subjective interpretation of activation maps. We hypothesized that application of machine learning to electrogram frequency spectra may accurately automate driver detection by MEM and add some objectivity to the interpretation of MEM findings. METHODS Temporally and spatially stable single AF drivers were mapped simultaneously in explanted human atria (n=11) by subsurface near-infrared optical mapping (NIOM; 0.3 mm2 resolution) and 64-electrode MEM (higher density or lower density with 3 and 9 mm2 resolution, respectively). Unipolar MEM and NIOM recordings were processed by Fourier transform analysis into 28 407 total Fourier spectra. Thirty-five features for machine learning were extracted from each Fourier spectrum. RESULTS Targeted driver ablation and NIOM activation maps efficiently defined the center and periphery of AF driver preferential tracks and provided validated annotations for driver versus nondriver electrodes in MEM arrays. Compared with analysis of single electrogram frequency features, averaging the features from each of the 8 neighboring electrodes, significantly improved classification of AF driver electrograms. The classification metrics increased when less strict annotation, including driver periphery electrodes, were added to driver center annotation. Notably, f1-score for the binary classification of higher-density catheter data set was significantly higher than that of lower-density catheter (0.81±0.02 versus 0.66±0.04, P<0.05). The trained algorithm correctly highlighted 86% of driver regions with higher density but only 80% with lower-density MEM arrays (81% for lower-density+higher-density arrays together). CONCLUSIONS The machine learning model pretrained on Fourier spectrum features allows efficient classification of electrograms recordings as AF driver or nondriver compared with the NIOM gold-standard. Future application of NIOM-validated machine learning approach may improve the accuracy of AF driver detection for targeted ablation treatment in patients.
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Affiliation(s)
- Alexander M Zolotarev
- Department of Physiology and Cell Biology and Bob and Corrine Frick Center for Heart Failure and Arrhythmia (A.M.Z., B.J.H., K.M.H., N.L., P.M.L.J., P.J.M., V.V.F.), The Ohio State University Wexner Medical Center, Columbus, OH.,Center of Computational and Data-Intensive Science and Engineering, Skolkovo Institute of Science and Technology, Moscow, Russia (A.M.Z., E.A.I., M.V.F., D.V.D.)
| | - Brian J Hansen
- Department of Physiology and Cell Biology and Bob and Corrine Frick Center for Heart Failure and Arrhythmia (A.M.Z., B.J.H., K.M.H., N.L., P.M.L.J., P.J.M., V.V.F.), The Ohio State University Wexner Medical Center, Columbus, OH
| | - Ekaterina A Ivanova
- Center of Computational and Data-Intensive Science and Engineering, Skolkovo Institute of Science and Technology, Moscow, Russia (A.M.Z., E.A.I., M.V.F., D.V.D.)
| | - Katelynn M Helfrich
- Department of Physiology and Cell Biology and Bob and Corrine Frick Center for Heart Failure and Arrhythmia (A.M.Z., B.J.H., K.M.H., N.L., P.M.L.J., P.J.M., V.V.F.), The Ohio State University Wexner Medical Center, Columbus, OH
| | - Ning Li
- Department of Physiology and Cell Biology and Bob and Corrine Frick Center for Heart Failure and Arrhythmia (A.M.Z., B.J.H., K.M.H., N.L., P.M.L.J., P.J.M., V.V.F.), The Ohio State University Wexner Medical Center, Columbus, OH.,Davis Heart and Lung Research Institute (N.L., P.M.L.J., P.J.M., N.A.M., B.A.W., J.D.H., V.V.F.), The Ohio State University Wexner Medical Center, Columbus, OH
| | - Paul M L Janssen
- Department of Physiology and Cell Biology and Bob and Corrine Frick Center for Heart Failure and Arrhythmia (A.M.Z., B.J.H., K.M.H., N.L., P.M.L.J., P.J.M., V.V.F.), The Ohio State University Wexner Medical Center, Columbus, OH.,Davis Heart and Lung Research Institute (N.L., P.M.L.J., P.J.M., N.A.M., B.A.W., J.D.H., V.V.F.), The Ohio State University Wexner Medical Center, Columbus, OH
| | - Peter J Mohler
- Department of Physiology and Cell Biology and Bob and Corrine Frick Center for Heart Failure and Arrhythmia (A.M.Z., B.J.H., K.M.H., N.L., P.M.L.J., P.J.M., V.V.F.), The Ohio State University Wexner Medical Center, Columbus, OH.,Davis Heart and Lung Research Institute (N.L., P.M.L.J., P.J.M., N.A.M., B.A.W., J.D.H., V.V.F.), The Ohio State University Wexner Medical Center, Columbus, OH
| | - Nahush A Mokadam
- Davis Heart and Lung Research Institute (N.L., P.M.L.J., P.J.M., N.A.M., B.A.W., J.D.H., V.V.F.), The Ohio State University Wexner Medical Center, Columbus, OH.,Division of Cardiac Surgery (N.A.M., B.A.W., J.D.H.), The Ohio State University Wexner Medical Center, Columbus, OH
| | - Bryan A Whitson
- Davis Heart and Lung Research Institute (N.L., P.M.L.J., P.J.M., N.A.M., B.A.W., J.D.H., V.V.F.), The Ohio State University Wexner Medical Center, Columbus, OH.,Division of Cardiac Surgery (N.A.M., B.A.W., J.D.H.), The Ohio State University Wexner Medical Center, Columbus, OH
| | - Maxim V Fedorov
- Center of Computational and Data-Intensive Science and Engineering, Skolkovo Institute of Science and Technology, Moscow, Russia (A.M.Z., E.A.I., M.V.F., D.V.D.)
| | - John D Hummel
- Davis Heart and Lung Research Institute (N.L., P.M.L.J., P.J.M., N.A.M., B.A.W., J.D.H., V.V.F.), The Ohio State University Wexner Medical Center, Columbus, OH.,Division of Cardiac Surgery (N.A.M., B.A.W., J.D.H.), The Ohio State University Wexner Medical Center, Columbus, OH.,Department of Internal Medicine (J.D.H), The Ohio State University Wexner Medical Center, Columbus, OH
| | - Dmitry V Dylov
- Center of Computational and Data-Intensive Science and Engineering, Skolkovo Institute of Science and Technology, Moscow, Russia (A.M.Z., E.A.I., M.V.F., D.V.D.)
| | - Vadim V Fedorov
- Department of Physiology and Cell Biology and Bob and Corrine Frick Center for Heart Failure and Arrhythmia (A.M.Z., B.J.H., K.M.H., N.L., P.M.L.J., P.J.M., V.V.F.), The Ohio State University Wexner Medical Center, Columbus, OH.,Davis Heart and Lung Research Institute (N.L., P.M.L.J., P.J.M., N.A.M., B.A.W., J.D.H., V.V.F.), The Ohio State University Wexner Medical Center, Columbus, OH
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Pharmacological rhythm versus rate control in patients with atrial fibrillation and heart failure: the CASTLE-AF trial. J Interv Card Electrophysiol 2020; 61:609-615. [DOI: 10.1007/s10840-020-00856-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 08/24/2020] [Indexed: 12/22/2022]
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Shi R, Chen Z, Butcher C, Zaman JAB, Boyalla V, Wang YK, Riad O, Sathishkumar A, Norman M, Haldar S, Jones DG, Hussain W, Markides V, Wong T. Diverse activation patterns during persistent atrial fibrillation by noncontact charge-density mapping of human atrium. J Arrhythm 2020; 36:692-702. [PMID: 32782641 PMCID: PMC7411208 DOI: 10.1002/joa3.12361] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Revised: 04/12/2020] [Accepted: 04/22/2020] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND Global simultaneous recording of atrial activation during atrial fibrillation (AF) can elucidate underlying mechanisms contributing to AF maintenance. A better understanding of these mechanisms may allow for an individualized ablation strategy to treat persistent AF. The study aims to characterize left atrial endocardial activation patterns during AF using noncontact charge-density mapping. METHODS Twenty-five patients with persistent AF were studied. Activation patterns were characterized into three subtypes: (i) focal with centrifugal activation (FCA); (ii) localized rotational activation (LRA); and (iii) localized irregular activation (LIA). Continuous activation patterns were analyzed and distributed in 18 defined regions in the left atrium. RESULTS A total of 144 AF segments with 1068 activation patterns were analyzed. The most common pattern during AF was LIA (63%) which consists of four disparate features of activation: slow conduction (45%), pivoting (30%), collision (16%), and acceleration (7%). LRA was the second-most common pattern (20%). FCA accounted for 17% of all activations, arising frequently from the pulmonary veins (PVs)/ostia. A majority of patients (24/25; 96%) showed continuous and highly dynamic patterns of activation comprising multiple combinations of FCA, LRA, and LIA, transitioning from one to the other without a discernible order. Preferential conduction areas were typically seen in the mid-anterior (48%) and lower-posterior (40%) walls. CONCLUSION Atrial fibrillation is characterized by heterogeneous activation patterns identified in PV-ostia and non-PV regions throughout the LA at varying locations between individuals. Clinical implications of individualized ablation strategies guided by charge-density mapping need to be determined.
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Affiliation(s)
- Rui Shi
- Department of Cardiovascular MedicineThe First Affliated Hospital of Xi'an Jiaotong UniversityXi'anChina
- Heart Rhythm CentreThe Royal Brompton and Harefield NHS Foundation TrustNational Heart and Lung InstituteImperial College LondonLondonUK
| | - Zhong Chen
- Heart Rhythm CentreThe Royal Brompton and Harefield NHS Foundation TrustNational Heart and Lung InstituteImperial College LondonLondonUK
| | - Charlie Butcher
- Heart Rhythm CentreThe Royal Brompton and Harefield NHS Foundation TrustNational Heart and Lung InstituteImperial College LondonLondonUK
| | - Junaid AB Zaman
- Heart Rhythm CentreThe Royal Brompton and Harefield NHS Foundation TrustNational Heart and Lung InstituteImperial College LondonLondonUK
| | - Vennela Boyalla
- Heart Rhythm CentreThe Royal Brompton and Harefield NHS Foundation TrustNational Heart and Lung InstituteImperial College LondonLondonUK
| | - Yi Kan Wang
- Auckland Bioengineering InstituteUniversity of AucklandAucklandNew Zealand
| | - Omar Riad
- Heart Rhythm CentreThe Royal Brompton and Harefield NHS Foundation TrustNational Heart and Lung InstituteImperial College LondonLondonUK
| | - Anitha Sathishkumar
- Heart Rhythm CentreThe Royal Brompton and Harefield NHS Foundation TrustNational Heart and Lung InstituteImperial College LondonLondonUK
| | - Mark Norman
- Heart Rhythm CentreThe Royal Brompton and Harefield NHS Foundation TrustNational Heart and Lung InstituteImperial College LondonLondonUK
| | - Shouvik Haldar
- Heart Rhythm CentreThe Royal Brompton and Harefield NHS Foundation TrustNational Heart and Lung InstituteImperial College LondonLondonUK
| | - David G Jones
- Heart Rhythm CentreThe Royal Brompton and Harefield NHS Foundation TrustNational Heart and Lung InstituteImperial College LondonLondonUK
| | - Wajid Hussain
- Heart Rhythm CentreThe Royal Brompton and Harefield NHS Foundation TrustNational Heart and Lung InstituteImperial College LondonLondonUK
| | - Vias Markides
- Heart Rhythm CentreThe Royal Brompton and Harefield NHS Foundation TrustNational Heart and Lung InstituteImperial College LondonLondonUK
| | - Tom Wong
- Heart Rhythm CentreThe Royal Brompton and Harefield NHS Foundation TrustNational Heart and Lung InstituteImperial College LondonLondonUK
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Yadava RS, Yu Q, Mandal M, Rigo F, Bennett CF, Mahadevan MS. Systemic therapy in an RNA toxicity mouse model with an antisense oligonucleotide therapy targeting a non-CUG sequence within the DMPK 3'UTR RNA. Hum Mol Genet 2020; 29:1440-1453. [PMID: 32242217 PMCID: PMC7268549 DOI: 10.1093/hmg/ddaa060] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 03/19/2020] [Accepted: 03/30/2020] [Indexed: 12/17/2022] Open
Abstract
Myotonic dystrophy type 1 (DM1), the most common adult muscular dystrophy, is an autosomal dominant disorder caused by an expansion of a (CTG)n tract within the 3' untranslated region (3'UTR) of the dystrophia myotonica protein kinase (DMPK) gene. Mutant DMPK mRNAs are toxic, present in nuclear RNA foci and correlated with a plethora of RNA splicing defects. Cardinal features of DM1 are myotonia and cardiac conduction abnormalities. Using transgenic mice, we have demonstrated that expression of the mutant DMPK 3'UTR is sufficient to elicit these features of DM1. Here, using these mice, we present a study of systemic treatment with an antisense oligonucleotide (ASO) (ISIS 486178) targeted to a non-CUG sequence within the 3'UTR of DMPK. RNA foci and DMPK 3'UTR mRNA levels were reduced in both the heart and skeletal muscles. This correlated with improvements in several splicing defects in skeletal and cardiac muscles. The treatment reduced myotonia and this correlated with increased Clcn1 expression. Furthermore, functional testing showed improvements in treadmill running. Of note, we demonstrate that the ASO treatment reversed the cardiac conduction abnormalities, and this correlated with restoration of Gja5 (connexin 40) expression in the heart. This is the first time that an ASO targeting a non-CUG sequence within the DMPK 3'UTR has demonstrated benefit on the key DM1 phenotypes of myotonia and cardiac conduction defects. Our data also shows for the first time that ASOs may be a viable option for treating cardiac pathology in DM1.
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Affiliation(s)
- Ramesh S Yadava
- Department of Pathology, University of Virginia, Charlottesville, VA 22908, USA
| | - Qing Yu
- Department of Pathology, University of Virginia, Charlottesville, VA 22908, USA
| | - Mahua Mandal
- Department of Pathology, University of Virginia, Charlottesville, VA 22908, USA
| | - Frank Rigo
- Ionis Pharmaceuticals Inc., Carlsbad, CA 90210, USA
| | | | - Mani S Mahadevan
- Department of Pathology, University of Virginia, Charlottesville, VA 22908, USA
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Bai J, Lu Y, Lo A, Zhao J, Zhang H. PITX2 upregulation increases the risk of chronic atrial fibrillation in a dose-dependent manner by modulating IKs and ICaL -insights from human atrial modelling. ANNALS OF TRANSLATIONAL MEDICINE 2020; 8:191. [PMID: 32309338 PMCID: PMC7154416 DOI: 10.21037/atm.2020.01.90] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Background Functional analysis has shown that the paired-like homeodomain transcription factor 2 (PITX2) overexpression associated with atrial fibrillation (AF) leads to the slow delayed rectifier K+ current (IKs) increase and the L-type Ca2+ current (ICaL) reduction observed in isolated right atrial myocytes from chronic AF (CAF) patients. Through multiscale computational models, this study aimed to investigate the functional impact of the PITX2 overexpression on atrial electrical activity. Methods The well-known Courtemanche-Ramirez-Nattel (CRN) model of human atrial action potentials (APs) was updated to incorporate experimental data on alterations in IKs and ICaL due to the PITX2 overexpression. These cell models for sinus rhythm (SR) and CAF were then incorporated into homogeneous multicellular one-dimensional (1D), two-dimensional (2D), and three-dimensional (3D) tissue models. The proarrhythmic effects of the PITX2 overexpression were quantified with ion current profiles, AP morphology, AP duration (APD) restitution, conduction velocity restitution (CVR), wavelength (WL), vulnerable window (VW) for unidirectional conduction block, and minimal substrate size required to induce re-entry. Dynamic behaviors of spiral waves were characterized by measuring lifespan (LS), tip patterns and dominant frequencies. Results The IKs increase and the ICaL decrease arising from the PITX2 overexpression abbreviated APD and flattened APD restitution (APDR) curves in single cells. It reduced WL and increased CV at high excitation rates at the 1D tissue level. Although it had no effects on VW for initiating spiral waves, it decreased the minimal substrate size necessary to sustain re-entry. It also stabilized and accelerated spiral waves in 2D and 3D tissue models. Conclusions Electrical remodeling (IKs and ICaL) due to the PITX2 overexpression increases susceptibility to AF due to increased tissue vulnerability, abbreviated APD, shortened WL and altered CV, which, in combination, facilitate initiation and maintenance of spiral waves.
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Affiliation(s)
- Jieyun Bai
- Department of Electronic Engineering, College of Information Science and Technology, Jinan University, Guangzhou 510632, China
| | - Yaosheng Lu
- Department of Electronic Engineering, College of Information Science and Technology, Jinan University, Guangzhou 510632, China
| | - Andy Lo
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Jichao Zhao
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Henggui Zhang
- Biological Physics Group, School of Physics & Astronomy, University of Manchester, Manchester, UK
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Kiuchi K, Fukuzawa K, Nogami M, Watanabe Y, Takami M, Mori S, Shimoyama S, Negi N, Kyotani K, Hirata KI. Visualization of Inflammation After Cryoballoon Ablation in Atrial Fibrillation Patients - Protocol for Proof-of-Concept Feasibility Trial. Circ Rep 2020; 1:149-152. [PMID: 33693130 PMCID: PMC7890275 DOI: 10.1253/circrep.cr-19-0003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Background:
Atrial fibrosis and inflammation play important roles in perpetuating and initiating atrial fibrillation (AF). Although the fibrotic area can be visualized as a delayed enhancement area on late gadolinium enhancement magnetic resonance imaging (LGE-MRI), atrial inflammation has not yet been visualized on any imaging modality. We describe the protocol for a feasibility study to visualize atrial inflammation on positron emission tomography/MRI (PET/MRI). Methods and Results:
This is a single-arm, prospective, open-label proof-of concept trial, involving AF patients after cryoballoon ablation (CBA). A total of 30 paroxysmal AF patients will be enrolled and undergo simultaneous PET/MRI for the assessment of regional 18F-fluorodeoxyglucose (18F-FDG) uptake 1 day after the CBA. Furthermore, LGE-MRI will be performed before CBA, and at 1 and 4 weeks after assessing the regional LGE area. The main outcome measures will be (1) the feasibility of imaging inflammation in the left atrium on PET/MRI; and (2) the safety of the intervention. Conclusions:
There are few data on the visualization of atrial inflammation using PET/MRI. Establishing the visualization methodology will contribute to elucidating the fundamental histopathologic findings of the progress to fibrosis, and to the planning and execution of a larger definitive trial to test the usefulness of PET/MRI.
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Affiliation(s)
- Kunihiko Kiuchi
- Section of Arrhythmia, Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine Kobe Japan
| | - Koji Fukuzawa
- Section of Arrhythmia, Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine Kobe Japan
| | - Munenobu Nogami
- Department of Radiology, Kobe University Graduate School of Medicine Kobe Japan
| | - Yoshiaki Watanabe
- Department of Radiology, Kobe University Graduate School of Medicine Kobe Japan
| | - Mitsuru Takami
- Section of Arrhythmia, Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine Kobe Japan
| | - Shumpei Mori
- Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine Kobe Japan
| | - Shinsuke Shimoyama
- Department of Radiology, Kobe University Graduate School of Medicine Kobe Japan
| | - Noriyuki Negi
- Division of Radiology, Center for Radiology and Radiation Oncology, Kobe University Hospital Kobe Japan
| | - Katsusuke Kyotani
- Division of Radiology, Center for Radiology and Radiation Oncology, Kobe University Hospital Kobe Japan
| | - Ken-Ichi Hirata
- Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine Kobe Japan
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Li J, Chen R, Wu J. Structural Analysis of Complex Atrial Intramural Microstructure from A Multi-layer Model Based on Siamese Network. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2020; 2019:294-297. [PMID: 31945899 DOI: 10.1109/embc.2019.8857276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Quantitative analysis of complex atrial intramural microstructure is a crucial step towards understanding the mechanism behind atrial fibrillation (AF) maintenance. Siamese network was adopted to extract features from computationally simulated multi-layer fibrosis structure. Through analysis of the features produced by the feature extractor, the difference between Non-sustained and Sustained simulations was comprehended intuitively and electrophysiologically. Complex conduction pathway marked by the feature extractor might be an indicator for AF radio-frequency ablation clinically.
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Nakamura T, Kiuchi K, Fukuzawa K, Takami M, Akita T, Suehiro H, Takemoto M, Sakai J, Yatomi A, Sonoda Y, Takahara H, Nakasone K, Yamamoto K, Hirata K, Ashihara T. Successful modulation of atrial fibrillation drivers anchoring to fibrotic tissue after box isolation using an online real-time phase mapping system: ExTRa Mapping. J Arrhythm 2019; 35:733-736. [PMID: 31624512 PMCID: PMC6786983 DOI: 10.1002/joa3.12232] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 08/14/2019] [Accepted: 08/22/2019] [Indexed: 12/30/2022] Open
Abstract
A 41-year-old man with persistent atrial fibrillation (AF) underwent radiofrequency (RF) catheter ablation using an online real-time phase mapping system: ExTRa Mapping. Box isolation could not terminate AF. Subsequently, RF applications on nonpassively activated areas (NPAs), where rotational activations were frequently observed, at the posterior bottom of left atrium outside of box lesion could convert AF to common atrial flutter. Of interest, the NPA near the posterior bottom were located on the patchy fibrotic tissue area assessed by the late-gadolinium enhancement magnetic resonance imaging. This indicated the possibility of the critical AF rotor meandering through the fibrotic tissue area.
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Affiliation(s)
- Toshihiro Nakamura
- Section of ArrhythmiaDivision of Cardiovascular MedicineDepartment of Internal MedicineKobe University Graduate School of MedicineHyogoJapan
| | - Kunihiko Kiuchi
- Section of ArrhythmiaDivision of Cardiovascular MedicineDepartment of Internal MedicineKobe University Graduate School of MedicineHyogoJapan
| | - Koji Fukuzawa
- Section of ArrhythmiaDivision of Cardiovascular MedicineDepartment of Internal MedicineKobe University Graduate School of MedicineHyogoJapan
| | - Mitsuru Takami
- Section of ArrhythmiaDivision of Cardiovascular MedicineDepartment of Internal MedicineKobe University Graduate School of MedicineHyogoJapan
| | - Tomomi Akita
- Section of ArrhythmiaDivision of Cardiovascular MedicineDepartment of Internal MedicineKobe University Graduate School of MedicineHyogoJapan
| | - Hideya Suehiro
- Section of ArrhythmiaDivision of Cardiovascular MedicineDepartment of Internal MedicineKobe University Graduate School of MedicineHyogoJapan
| | - Makoto Takemoto
- Section of ArrhythmiaDivision of Cardiovascular MedicineDepartment of Internal MedicineKobe University Graduate School of MedicineHyogoJapan
| | - Jun Sakai
- Section of ArrhythmiaDivision of Cardiovascular MedicineDepartment of Internal MedicineKobe University Graduate School of MedicineHyogoJapan
| | - Atsusuke Yatomi
- Section of ArrhythmiaDivision of Cardiovascular MedicineDepartment of Internal MedicineKobe University Graduate School of MedicineHyogoJapan
| | - Yusuke Sonoda
- Section of ArrhythmiaDivision of Cardiovascular MedicineDepartment of Internal MedicineKobe University Graduate School of MedicineHyogoJapan
| | - Hiroyuki Takahara
- Section of ArrhythmiaDivision of Cardiovascular MedicineDepartment of Internal MedicineKobe University Graduate School of MedicineHyogoJapan
| | - Kazutaka Nakasone
- Section of ArrhythmiaDivision of Cardiovascular MedicineDepartment of Internal MedicineKobe University Graduate School of MedicineHyogoJapan
| | - Kyoko Yamamoto
- Section of ArrhythmiaDivision of Cardiovascular MedicineDepartment of Internal MedicineKobe University Graduate School of MedicineHyogoJapan
| | - Ken‐ichi Hirata
- Section of ArrhythmiaDivision of Cardiovascular MedicineDepartment of Internal MedicineKobe University Graduate School of MedicineHyogoJapan
| | - Takashi Ashihara
- Department of Medical Informatics and Biomedical EngineeringShiga University of Medical ScienceOtsuJapan
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Bayer JD, Boukens BJ, Krul SPJ, Roney CH, Driessen AHG, Berger WR, van den Berg NWE, Verkerk AO, Vigmond EJ, Coronel R, de Groot JR. Acetylcholine Delays Atrial Activation to Facilitate Atrial Fibrillation. Front Physiol 2019; 10:1105. [PMID: 31551802 PMCID: PMC6737394 DOI: 10.3389/fphys.2019.01105] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 08/09/2019] [Indexed: 11/13/2022] Open
Abstract
Background Acetylcholine (ACh) shortens action potential duration (APD) in human atria. APD shortening facilitates atrial fibrillation (AF) by reducing the wavelength for reentry. However, the influence of ACh on electrical conduction in human atria and its contribution to AF are unclear, particularly when combined with impaired conduction from interstitial fibrosis. Objective To investigate the effect of ACh on human atrial conduction and its role in AF with computational, experimental, and clinical approaches. Methods S1S2 pacing (S1 = 600 ms and S2 = variable cycle lengths) was applied to the following human AF computer models: a left atrial appendage (LAA) myocyte to quantify the effects of ACh on APD, maximum upstroke velocity (V max ), and resting membrane potential (RMP); a monolayer of LAA myocytes to quantify the effects of ACh on conduction; and 3) an intact left atrium (LA) to determine the effects of ACh on arrhythmogenicity. Heterogeneous ACh and interstitial fibrosis were applied to the monolayer and LA models. To corroborate the simulations, APD and RMP from isolated human atrial myocytes were recorded before and after 0.1 μM ACh. At the tissue level, LAAs from AF patients were optically mapped ex vivo using Di-4-ANEPPS. The difference in total activation time (AT) was determined between AT initially recorded with S1 pacing, and AT recorded during subsequent S1 pacing without (n = 6) or with (n = 7) 100 μM ACh. Results In LAA myocyte simulations, S1 pacing with 0.1 μM ACh shortened APD by 41 ms, hyperpolarized RMP by 7 mV, and increased V max by 27 mV/ms. In human atrial myocytes, 0.1 μM ACh shortened APD by 48 ms, hyperpolarized RMP by 3 mV, and increased V max by 6 mV/ms. In LAA monolayer simulations, S1 pacing with ACh hyperpolarized RMP to delay total AT by 32 ms without and 35 ms with fibrosis. This led to unidirectional conduction block and sustained reentry in fibrotic LA with heterogeneous ACh during S2 pacing. In AF patient LAAs, S1 pacing with ACh increased total AT from 39.3 ± 26 ms to 71.4 ± 31.2 ms (p = 0.036) compared to no change without ACh (56.7 ± 29.3 ms to 50.0 ± 21.9 ms, p = 0.140). Conclusion In fibrotic atria with heterogeneous parasympathetic activation, ACh facilitates AF by shortening APD and slowing conduction to promote unidirectional conduction block and reentry.
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Affiliation(s)
- Jason D Bayer
- Electrophysiology and Heart Modeling Institute (IHU-LIRYC), Bordeaux University Foundation, Bordeaux, France.,Institute of Mathematics of Bordeaux (U5251), University of Bordeaux, Bordeaux, France
| | - Bastiaan J Boukens
- Department of Medical Biology, Academic Medical Center, Amsterdam, Netherlands
| | - Sébastien P J Krul
- Department of Cardiology, Academic Medical Center, Amsterdam, Netherlands
| | - Caroline H Roney
- Division of Imaging Sciences and Bioengineering, King's College London, London, United Kingdom
| | | | - Wouter R Berger
- Department of Cardiology, Academic Medical Center, Amsterdam, Netherlands.,Department of Cardiology, Heart Center, OLVG, Amsterdam, Netherlands
| | | | - Arie O Verkerk
- Department of Medical Biology, Academic Medical Center, Amsterdam, Netherlands.,Department of Experimental Cardiology, Academic Medical Center, Amsterdam, Netherlands
| | - Edward J Vigmond
- Electrophysiology and Heart Modeling Institute (IHU-LIRYC), Bordeaux University Foundation, Bordeaux, France.,Institute of Mathematics of Bordeaux (U5251), University of Bordeaux, Bordeaux, France
| | - Ruben Coronel
- Electrophysiology and Heart Modeling Institute (IHU-LIRYC), Bordeaux University Foundation, Bordeaux, France.,Department of Experimental Cardiology, Academic Medical Center, Amsterdam, Netherlands
| | - Joris R de Groot
- Department of Cardiology, Academic Medical Center, Amsterdam, Netherlands
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Tzeis S, Asvestas D, Vardas P. Atrial Fibrosis: Translational Considerations for the Management of AF Patients. Arrhythm Electrophysiol Rev 2019; 8:37-41. [PMID: 30918665 PMCID: PMC6434500 DOI: 10.15420/aer.2018.79.3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Fibrosis plays a fundamental role in the initiation and maintenance of AF, mainly due to enhanced automaticity and anisotropy-related re-entry. The identification and quantification of atrial fibrosis is achieved either preprocedurally by late gadolinium enhancement MRI or intraprocedurally using electroanatomic voltage mapping. The presence and extent of left atrial fibrosis among AF patients may influence relevant decision making regarding the need for anticoagulation, the adoption of rate versus rhythm control and mainly the type of ablation strategy that will be followed during interventional treatment. Several types of individualised substrate modifications targeting atrial fibrotic areas have been proposed, although their impact on patient outcome needs to be further investigated in adequately powered prospective randomised controlled clinical trials.
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Affiliation(s)
- Stylianos Tzeis
- Cardiology Department, Mitera General Hospital, Hygeia Group Athens, Greece
| | - Dimitrios Asvestas
- Cardiology Department, Mitera General Hospital, Hygeia Group Athens, Greece
| | - Panos Vardas
- Heart Sector, Hygeia Group Hospitals Athens, Greece
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Bening C, Mazalu EA, Yaqub J, Alhussini K, Glanowski M, Kottmann T, Leyh R. Atrial contractility and fibrotic biomarkers are associated with atrial fibrillation after elective coronary artery bypass grafting. J Thorac Cardiovasc Surg 2019; 159:515-523. [PMID: 30929988 DOI: 10.1016/j.jtcvs.2019.02.068] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 02/14/2019] [Accepted: 02/15/2019] [Indexed: 12/20/2022]
Abstract
OBJECTIVE New-onset postoperative atrial fibrillation is common after cardiac surgery. Less has been reported about the relationship among fibrosis, inflammation, calcium-induced left atrial and right atrial contractile forces, and postoperative atrial fibrillation. We sought to identify predictors of postoperative atrial fibrillation. METHODS From August 2016 to February 2018, we evaluated 229 patients who had preoperative sinus rhythm before elective primary coronary artery bypass grafting. Of 229 patients, 191 maintained sinus rhythm postoperatively, whereas 38 patients developed atrial fibrillation. Preoperative tissue inhibitor of metalloproteinase-1, pentraxin-3, matrix metallopeptidase-9, galectin-3, high-sensitivity C-reactive protein, growth differentiation factor 15, and transforming growth factor-ß were measured. Clinical and echocardiographic findings (tricuspid annular plane systolic excursion for right heart function) and calcium-induced force measurements from left atrial and right atrial-derived skinned myocardial fibers were recorded. RESULTS Patients with atrial fibrillation were older (P = .001), had enlarged left atrial (P = .0001) and right atrial areas (P = .0001), and had decreased tricuspid annular plane systolic excursion (P = .001). Levels of matrix metallopeptidase-9 and pentraxin-3 were decreased (P < .05), whereas growth differentiation factor 15 was increased (P = .001). We detected lower left atrial force values at calcium-induced force measurements 5.5 (P < .05), 5.4 (P < .01), and 5.3 to 4.52 (P = .0001) and right atrial force values at calcium-induced force measurements 5.0 to 4.52 (P < .05) in patients with postoperative atrial fibrillation. Multivariable analysis showed that advanced age (P = .033), decreased left atrial force value at calcium-induced force measurement of 5.5 (P = .033), enlarged left atrial (P = .013) and right atrial (P = .081) areas, and reduced tricuspid annular plane systolic excursion (P = .010) independently predicted postoperative atrial fibrillation. CONCLUSIONS Advanced age, decreased left atrial force value at calcium-induced force measurement of 5.5, enlarged left atrial and right atrial areas, and reduced tricuspid annular plane systolic excursion were identified as independent predictors for postoperative atrial fibrillation.
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Affiliation(s)
- Constanze Bening
- Department of Thoracic and Cardiovascular Surgery, University of Wuerzburg, Wuerzburg, Germany; Comprehensive Heart Failure Centre Würzburg, University of Wuerzburg, Wuerzburg, Germany.
| | - Elena-Aura Mazalu
- Department of Thoracic and Cardiovascular Surgery, University of Wuerzburg, Wuerzburg, Germany
| | - Jonathan Yaqub
- Department of Thoracic and Cardiovascular Surgery, University of Wuerzburg, Wuerzburg, Germany
| | - Khaled Alhussini
- Department of Thoracic and Cardiovascular Surgery, University of Wuerzburg, Wuerzburg, Germany
| | - Michal Glanowski
- Department of Thoracic and Cardiovascular Surgery, University of Wuerzburg, Wuerzburg, Germany
| | | | - Rainer Leyh
- Department of Thoracic and Cardiovascular Surgery, University of Wuerzburg, Wuerzburg, Germany; Comprehensive Heart Failure Centre Würzburg, University of Wuerzburg, Wuerzburg, Germany
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Jilek C, Ullah W. Pulmonary vein reconnections or substrate in the left atrium: what is the reason for atrial fibrillation recurrences? A dialogue on a pressing clinical situation. Europace 2019; 21:i12-i20. [DOI: 10.1093/europace/euy289] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Accepted: 01/05/2019] [Indexed: 01/08/2023] Open
Affiliation(s)
- Clemens Jilek
- Internistisches Klinikum München Süd, Peter-Osypka-Heart Centre, Munich, Germany
| | - Waqas Ullah
- Cardiology Department, University Hospital Southampton, National Health Service Foundation Trust, Southampton, UK
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Ganesan P, Salmin A, Cherry EM, Huang DT, Pertsov AM, Ghoraani B. Iterative navigation of multipole diagnostic catheters to locate repeating-pattern atrial fibrillation drivers. J Cardiovasc Electrophysiol 2019; 30:758-768. [PMID: 30725499 PMCID: PMC6554033 DOI: 10.1111/jce.13872] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 01/16/2019] [Accepted: 01/31/2019] [Indexed: 01/01/2023]
Abstract
Introduction Targeting repeating‐pattern atrial fibrillation (AF) sources (reentry or focal drivers) can help in patient‐specific ablation therapy for AF; however, the development of reliable and accurate tools for locating such sources remains a major challenge. We describe iterative catheter navigation (ICAN) algorithm to locate AF drivers using a conventional circular Lasso catheter. Methods and Results At each step, the algorithm analyzes 10 bipolar electrograms recoded at a given catheter location and the history of previous catheter movements to determine if the source is inside the catheter loop. If not, it calculates new coordinates and selects a new position for the catheter. The process continues until a source is located. The algorithm was evaluated in a computer model of atrial tissue with various degrees of fibrosis under a broad range of arrhythmia scenarios. The latter included slow and fast reentry, macroreentry, figure‐of‐eight reentry, and fibrillatory conduction. Depending on the initial distance of the catheter from the source and scenario, it took about 3 to 16 steps to localize an AF source. In 94% of cases, the identified location was within 4 mm from the source, independently of the initial position of the catheter. The algorithm worked equally well in the presence of patchy fibrosis, low‐voltage areas, fragmented electrograms, and dominant‐frequency gradients. Conclusions AF repeating‐pattern sources can be localized using circular catheters without the need to map the entire tissue. The proposed algorithm has the potential to become a useful tool for patient‐specific ablation of AF sources located outside the pulmonary veins.
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Affiliation(s)
- Prasanth Ganesan
- Computer and Electrical Engineering and Computer Science, Florida Atlantic University, Boca Raton, Florida
| | - Anthony Salmin
- School of Mathematical Sciences, Rochester Institute of Technology, Rochester, New York
| | - Elizabeth M Cherry
- School of Mathematical Sciences, Rochester Institute of Technology, Rochester, New York
| | - David T Huang
- Department of Cardiology, University of Rochester Medical Center, Rochester, New York
| | - Arkady M Pertsov
- Department of Pharmacology, SUNY Upstate Medical Center, Syracuse, New York
| | - Behnaz Ghoraani
- Computer and Electrical Engineering and Computer Science, Florida Atlantic University, Boca Raton, Florida
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Xiong Z, Fedorov VV, Fu X, Cheng E, Macleod R, Zhao J. Fully Automatic Left Atrium Segmentation From Late Gadolinium Enhanced Magnetic Resonance Imaging Using a Dual Fully Convolutional Neural Network. IEEE TRANSACTIONS ON MEDICAL IMAGING 2019; 38:515-524. [PMID: 30716023 PMCID: PMC6364320 DOI: 10.1109/tmi.2018.2866845] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Atrial fibrillation (AF) is the most prevalent form of cardiac arrhythmia. Current treatments for AF remain suboptimal due to a lack of understanding of the underlying atrial structures that directly sustain AF. Existing approaches for analyzing atrial structures in 3-D, especially from late gadolinium-enhanced (LGE) magnetic resonance imaging, rely heavily on manual segmentation methods that are extremely labor-intensive and prone to errors. As a result, a robust and automated method for analyzing atrial structures in 3-D is of high interest. We have, therefore, developed AtriaNet, a 16-layer convolutional neural network (CNN), on 154 3-D LGE-MRIs with a spatial resolution of 0.625 mm ×0.625 mm ×1.25 mm from patients with AF, to automatically segment the left atrial (LA) epicardium and endocardium. AtriaNet consists of a multi-scaled, dual-pathway architecture that captures both the local atrial tissue geometry and the global positional information of LA using 13 successive convolutions and three further convolutions for merging. By utilizing computationally efficient batch prediction, AtriaNet was able to successfully process each 3-D LGE-MRI within 1 min. Furthermore, benchmarking experiments have shown that AtriaNet has outperformed the state-of-the-art CNNs, with a DICE score of 0.940 and 0.942 for the LA epicardium and endocardium, respectively, and an inter-patient variance of <0.001. The estimated LA diameter and volume computed from the automatic segmentations were accurate to within 1.59 mm and 4.01 cm3 of the ground truths. Our proposed CNN was tested on the largest known data set for LA segmentation, and to the best of our knowledge, it is the most robust approach that has ever been developed for segmenting LGE-MRIs. The increased accuracy of atrial reconstruction and analysis could potentially improve the understanding and treatment of AF.
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Affiliation(s)
- Zhaohan Xiong
- VVF is with Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, USA. RM is with the Department of Bioengineering, University of Utah, Salt Lake City, USA
| | - Vadim V. Fedorov
- VVF is with Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, USA. RM is with the Department of Bioengineering, University of Utah, Salt Lake City, USA
| | - Xiaohang Fu
- VVF is with Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, USA. RM is with the Department of Bioengineering, University of Utah, Salt Lake City, USA
| | - Elizabeth Cheng
- VVF is with Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, USA. RM is with the Department of Bioengineering, University of Utah, Salt Lake City, USA
| | - Rob Macleod
- VVF is with Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, USA. RM is with the Department of Bioengineering, University of Utah, Salt Lake City, USA
| | - Jichao Zhao
- VVF is with Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, USA. RM is with the Department of Bioengineering, University of Utah, Salt Lake City, USA
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Chen R, Wen C, Fu R, Li J, Wu J. The effect of complex intramural microstructure caused by structural remodeling on the stability of atrial fibrillation: Insights from a three-dimensional multi-layer modeling study. PLoS One 2018; 13:e0208029. [PMID: 30485346 PMCID: PMC6261624 DOI: 10.1371/journal.pone.0208029] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2018] [Accepted: 11/10/2018] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Recent researches have suggested that the complex three-dimensional structures caused by structural remodeling play a key role in atrial fibrillation (AF) substrates. Here we aimed to investigate this hypothesis using a multi-layer model representing intramural microstructural features. METHODS The proposed multi-layer model was composed of the endocardium, connection wall, and epicardium. In the connection wall, intramural fibrosis was simulated using fibrotic patches randomly scattered in the myocardial tissue of fibrotic layers, while endo-epicardial dissociation was simulated using myocardial patches randomly scattered in the fibrotic tissue of isolation layers. Multiple simulation groups were generated to quantitatively analyze the effects of endo-epicardial dissociation and intramural fibrosis on AF stability, including a stochastic group, interrelated groups, fibrosis-degree-controlled groups, and dissociation-degree-controlled groups. RESULTS 1. Stable intramural re-entries were observed to move along complete re-entrant circuits inside the transmural wall in four of 65 simulations in the stochastic group. 2. About 21 of 23 stable simulations in the stochastic group were distributed in the areas with high endo-epicardial dissociation and intramural fibrosis. 3. The difference between fibrosis-degree-controlled groups and dissociation-degree-controlled groups suggested that some distributions of connection areas may affect AF episodes despite low intramural fibrosis and endo-epicardial dissociation. 4. The overview of tracking phase singularities revealed that endo-epicardial dissociation played a visible role in AF substrates. CONCLUSION The complex intramural microstructure is positively correlated with critical components of AF maintenance mechanisms. The occurrence of intramural re-entry further indicates the complexity of AF wave-dynamics.
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Affiliation(s)
- Riqing Chen
- Institute of Biomedical Engineering, Graduate School at Shenzhen, Tsinghua University, Shenzhen, China
| | - Cheng Wen
- Institute of Biomedical Engineering, Graduate School at Shenzhen, Tsinghua University, Shenzhen, China
| | - Rao Fu
- Institute of Biomedical Engineering, Graduate School at Shenzhen, Tsinghua University, Shenzhen, China
| | - Jianning Li
- Institute of Biomedical Engineering, Graduate School at Shenzhen, Tsinghua University, Shenzhen, China
| | - Jian Wu
- Institute of Biomedical Engineering, Graduate School at Shenzhen, Tsinghua University, Shenzhen, China
- * E-mail:
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Hansen BJ, Zhao J, Li N, Zolotarev A, Zakharkin S, Wang Y, Atwal J, Kalyanasundaram A, Abudulwahed SH, Helfrich KM, Bratasz A, Powell KA, Whitson B, Mohler PJ, Janssen PML, Simonetti OP, Hummel JD, Fedorov VV. Human Atrial Fibrillation Drivers Resolved With Integrated Functional and Structural Imaging to Benefit Clinical Mapping. JACC Clin Electrophysiol 2018; 4:1501-1515. [PMID: 30573112 DOI: 10.1016/j.jacep.2018.08.024] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 07/19/2018] [Accepted: 08/23/2018] [Indexed: 12/23/2022]
Abstract
OBJECTIVES This study sought to improve atrial fibrillation (AF) driver identification by integrating clinical multielectrode mapping with driver fingerprints defined by high-resolution ex vivo 3-dimensional (3D) functional and structural imaging. BACKGROUND Clinical multielectrode mapping of AF drivers suffers from variable contact, signal processing, and structural complexity within the 3D human atrial wall, raising questions on the validity of such drivers. METHODS Sustained AF was mapped in coronary-perfused explanted human hearts (n = 11) with transmural near-infrared optical mapping (∼0.3 mm2 resolution). Simultaneously, custom FIRMap catheters (∼9 × 9 mm2 resolution) mapped endocardial and epicardial surfaces, which were analyzed by Focal Impulse and Rotor Mapping activation and Rotational Activity Profile (Abbott Labs, Chicago, Illinois). Functional maps were integrated with contrast-enhanced cardiac magnetic resonance imaging (∼0.1 mm3 resolution) analysis of 3D fibrosis architecture. RESULTS During sustained AF, near-infrared optical mapping identified 1 to 2 intramural, spatially stable re-entrant AF drivers per heart. Driver targeted ablation affecting 2.2 ± 1.1% of the atrial surface terminated and prevented AF. Driver regions had significantly higher phase singularity density and dominant frequency than neighboring nondriver regions. Focal Impulse and Rotor Mapping had 80% sensitivity to near-infrared optical mapping-defined driver locations (16 of 20), and matched 14 of 20 driver visualizations: 10 of 14 re-entries seen with Rotational Activity Profile; and 4 of 6 breakthrough/focal patterns. Focal Impulse and Rotor Mapping detected 1.1 ± 0.9 false-positive rotational activity profiles per recording, but these regions had lower intramural contrast-enhanced cardiac magnetic resonance imaging fibrosis than did driver regions (14.9 ± 7.9% vs. 23.2 ± 10.5%; p < 0.005). CONCLUSIONS The study revealed that both re-entrant and breakthrough/focal AF driver patterns visualized by surface-only clinical multielectrodes can represent projections of 3D intramural microanatomic re-entries. Integration of multielectrode mapping and 3D fibrosis analysis may enhance AF driver detection, thereby improving the efficacy of driver-targeted ablation.
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Affiliation(s)
- Brian J Hansen
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, Ohio; Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Jichao Zhao
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Ning Li
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, Ohio; Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Alexander Zolotarev
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, Ohio; Phystech School of Biological and Medical Physics, Moscow Institute of Physic and Technology, Dolgoprudny, Russian Federation
| | - Stanislav Zakharkin
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Yufeng Wang
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Josh Atwal
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Anuradha Kalyanasundaram
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, Ohio; Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Suhaib H Abudulwahed
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Katelynn M Helfrich
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Anna Bratasz
- Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Kimerly A Powell
- Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Bryan Whitson
- Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio; Department of Surgery, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Peter J Mohler
- Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio; Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Paul M L Janssen
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, Ohio; Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Orlando P Simonetti
- Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio; Department of Biomedical Engineering, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - John D Hummel
- Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio; Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Vadim V Fedorov
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, Ohio; Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio.
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Bai J, Gladding PA, Stiles MK, Fedorov VV, Zhao J. Ionic and cellular mechanisms underlying TBX5/PITX2 insufficiency-induced atrial fibrillation: Insights from mathematical models of human atrial cells. Sci Rep 2018; 8:15642. [PMID: 30353147 PMCID: PMC6199257 DOI: 10.1038/s41598-018-33958-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 09/24/2018] [Indexed: 12/16/2022] Open
Abstract
Transcription factors TBX5 and PITX2 involve in the regulation of gene expression of ion channels and are closely associated with atrial fibrillation (AF), the most common cardiac arrhythmia in developed countries. The exact cellular and molecular mechanisms underlying the increased susceptibility to AF in patients with TBX5/PITX2 insufficiency remain unclear. In this study, we have developed and validated a novel human left atrial cellular model (TPA) based on the ten Tusscher-Panfilov ventricular cell model to systematically investigate how electrical remodeling induced by TBX5/PITX2 insufficiency leads to AF. Using our TPA model, we have demonstrated that spontaneous diastolic depolarization observed in atrial myocytes with TBX5-deletion can be explained by altered intracellular calcium handling and suppression of inward-rectifier potassium current (IK1). Additionally, our computer simulation results shed new light on the novel cellular mechanism underlying AF by indicating that the imbalance between suppressed outward current IK1 and increased inward sodium-calcium exchanger current (INCX) resulted from SR calcium leak leads to spontaneous depolarizations. Furthermore, our simulation results suggest that these arrhythmogenic triggers can be potentially suppressed by inhibiting sarcoplasmic reticulum (SR) calcium leak and reversing remodeled IK1. More importantly, this study has clinically significant implications on the drugs used for maintaining SR calcium homeostasis, whereby drugs such as dantrolene may confer significant improvement for the treatment of AF patients with TBX5/PITX2 insufficiency.
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Affiliation(s)
- Jieyun Bai
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand.
- School of Computer Science and Technology, Harbin Institute Technology, Harbin, China.
| | - Patrick A Gladding
- Department of Cardiology, Waitemata District Health Board, Auckland, New Zealand
| | | | - Vadim V Fedorov
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, United States of America
| | - Jichao Zhao
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand.
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49
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Cheniti G, Vlachos K, Pambrun T, Hooks D, Frontera A, Takigawa M, Bourier F, Kitamura T, Lam A, Martin C, Dumas-Pommier C, Puyo S, Pillois X, Duchateau J, Klotz N, Denis A, Derval N, Jais P, Cochet H, Hocini M, Haissaguerre M, Sacher F. Atrial Fibrillation Mechanisms and Implications for Catheter Ablation. Front Physiol 2018; 9:1458. [PMID: 30459630 PMCID: PMC6232922 DOI: 10.3389/fphys.2018.01458] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 09/26/2018] [Indexed: 01/14/2023] Open
Abstract
AF is a heterogeneous rhythm disorder that is related to a wide spectrum of etiologies and has broad clinical presentations. Mechanisms underlying AF are complex and remain incompletely understood despite extensive research. They associate interactions between triggers, substrate and modulators including ionic and anatomic remodeling, genetic predisposition and neuro-humoral contributors. The pulmonary veins play a key role in the pathogenesis of AF and their isolation is associated to high rates of AF freedom in patients with paroxysmal AF. However, ablation of persistent AF remains less effective, mainly limited by the difficulty to identify the sources sustaining AF. Many theories were advanced to explain the perpetuation of this form of AF, ranging from a single localized focal and reentrant source to diffuse bi-atrial multiple wavelets. Translating these mechanisms to the clinical practice remains challenging and limited by the spatio-temporal resolution of the mapping techniques. AF is driven by focal or reentrant activities that are initially clustered in a relatively limited atrial surface then disseminate everywhere in both atria. Evidence for structural remodeling, mainly represented by atrial fibrosis suggests that reentrant activities using anatomical substrate are the key mechanism sustaining AF. These reentries can be endocardial, epicardial, and intramural which makes them less accessible for mapping and for ablation. Subsequently, early interventions before irreversible remodeling are of major importance. Circumferential pulmonary vein isolation remains the cornerstone of the treatment of AF, regardless of the AF form and of the AF duration. No ablation strategy consistently demonstrated superiority to pulmonary vein isolation in preventing long term recurrences of atrial arrhythmias. Further research that allows accurate identification of the mechanisms underlying AF and efficient ablation should improve the results of PsAF ablation.
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Affiliation(s)
- Ghassen Cheniti
- Cardiac Electrophysiology Department, Hopital Haut Leveque, Bordeaux, France.,Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France.,Cardiology Department, Hopital Sahloul, Universite de Sousse, Sousse, Tunisia
| | - Konstantinos Vlachos
- Cardiac Electrophysiology Department, Hopital Haut Leveque, Bordeaux, France.,Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France
| | - Thomas Pambrun
- Cardiac Electrophysiology Department, Hopital Haut Leveque, Bordeaux, France.,Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France
| | - Darren Hooks
- Cardiology Department, Wellington Hospital, Wellington, New Zealand
| | - Antonio Frontera
- Cardiac Electrophysiology Department, Hopital Haut Leveque, Bordeaux, France.,Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France
| | - Masateru Takigawa
- Cardiac Electrophysiology Department, Hopital Haut Leveque, Bordeaux, France.,Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France
| | - Felix Bourier
- Cardiac Electrophysiology Department, Hopital Haut Leveque, Bordeaux, France.,Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France
| | - Takeshi Kitamura
- Cardiac Electrophysiology Department, Hopital Haut Leveque, Bordeaux, France.,Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France
| | - Anna Lam
- Cardiac Electrophysiology Department, Hopital Haut Leveque, Bordeaux, France.,Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France
| | - Claire Martin
- Cardiac Electrophysiology Department, Hopital Haut Leveque, Bordeaux, France.,Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France
| | | | - Stephane Puyo
- Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France
| | - Xavier Pillois
- Cardiac Electrophysiology Department, Hopital Haut Leveque, Bordeaux, France
| | - Josselin Duchateau
- Cardiac Electrophysiology Department, Hopital Haut Leveque, Bordeaux, France.,Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France
| | - Nicolas Klotz
- Cardiac Electrophysiology Department, Hopital Haut Leveque, Bordeaux, France.,Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France
| | - Arnaud Denis
- Cardiac Electrophysiology Department, Hopital Haut Leveque, Bordeaux, France.,Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France
| | - Nicolas Derval
- Cardiac Electrophysiology Department, Hopital Haut Leveque, Bordeaux, France.,Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France
| | - Pierre Jais
- Cardiac Electrophysiology Department, Hopital Haut Leveque, Bordeaux, France.,Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France
| | - Hubert Cochet
- Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France.,Department of Cardiovascular Imaging, Hopital Haut Leveque, Bordeaux, France
| | - Meleze Hocini
- Cardiac Electrophysiology Department, Hopital Haut Leveque, Bordeaux, France.,Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France
| | - Michel Haissaguerre
- Cardiac Electrophysiology Department, Hopital Haut Leveque, Bordeaux, France.,Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France
| | - Frederic Sacher
- Cardiac Electrophysiology Department, Hopital Haut Leveque, Bordeaux, France.,Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France
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50
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Burashnikov A, Antzelevitch C. Is extensive atrial fibrosis in the setting of heart failure associated with a reduced atrial fibrillation burden? PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2018; 41:1289-1297. [PMID: 30152017 DOI: 10.1111/pace.13474] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 08/07/2018] [Accepted: 08/16/2018] [Indexed: 01/30/2023]
Abstract
Atrial fibrillation (AF) affects 10-50% of patients with chronic heart failure (HF) and is associated with poor long-term prognosis. AF is commonly associated with atrial structural remodeling (ASR), principally characterized by atrial dilatation and fibrosis. However, the occurrence of AF in the full spectrum of ASR encountered in patients with HF is poorly defined. Experimental studies have presented evidence that extensive ASR can be accompanied with a reduced burden of AF, secondary to a prominent depression of atrial excitability. This reduction in AF burden is associated with severe atrial fibrosis rather than with dilatation. Clinical studies of patients with HF point to the possibility that advanced ASR is associated with a less frequent AF occurrence than moderate ASR. Our goal in this review is to introduce the hypothesis that AF is less likely to occur in severe versus moderate atrial ASR in the setting of HF and that it is severe atrial fibrosis-associated depression of atrial excitability that reduces AF burden.
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Affiliation(s)
- Alexander Burashnikov
- Lankenau Institute for Medical Research, Wynnewood, PA, USA.,Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, PA, USA
| | - Charles Antzelevitch
- Lankenau Institute for Medical Research, Wynnewood, PA, USA.,Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, PA, USA.,Lankenau Heart Institute, Main Line Health, Wynnewood, PA, USA
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