1
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Lorenzo-Almorós A, Casado Cerrada J, Álvarez-Sala Walther LA, Méndez Bailón M, Lorenzo González Ó. Atrial Fibrillation and Diabetes Mellitus: Dangerous Liaisons or Innocent Bystanders? J Clin Med 2023; 12:jcm12082868. [PMID: 37109205 PMCID: PMC10142815 DOI: 10.3390/jcm12082868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 03/27/2023] [Accepted: 04/12/2023] [Indexed: 04/29/2023] Open
Abstract
Atrial fibrillation (AF) is the most common arrhythmia in adults and diabetes mellitus (DM) is a major risk factor for cardiovascular diseases. However, the relationship between both pathologies has not been fully documented and new evidence supports the existence of direct and independent links. In the myocardium, a combination of structural, electrical, and autonomic remodeling may lead to AF. Importantly, patients with AF and DM showed more dramatic alterations than those with AF or DM alone, particularly in mitochondrial respiration and atrial remodeling, which alters conductivity, thrombogenesis, and contractile function. In AF and DM, elevations of cytosolic Ca2⁺ and accumulation of extra cellular matrix (ECM) proteins at the interstitium can promote delayed afterdepolarizations. The DM-associated low-grade inflammation and deposition/infiltration of epicardial adipose tissue (EAT) enforce abnormalities in Ca2+ handling and in excitation-contraction coupling, leading to atrial myopathy. This atrial enlargement and the reduction in passive emptying volume and fraction can be key for AF maintenance and re-entry. Moreover, the stored EAT can prolong action of potential durations and progression from paroxysmal to persistent AF. In this way, DM may increase the risk of thrombogenesis as a consequence of increased glycation and oxidation of fibrinogen and plasminogen, impairing plasmin conversion and resistance to fibrinolysis. Additionally, the DM-associated autonomic remodeling may also initiate AF and its re-entry. Finally, further evidence of DM influence on AF development and maintenance are based on the anti-arrhythmogenic effects of certain anti-diabetic drugs like SGLT2 inhibitors. Therefore, AF and DM may share molecular alterations related to Ca2+ mobility, mitochondrial function and ECM composition that induce atrial remodeling and defects in autonomic stimulation and conductivity. Likely, some specific therapies could work against the associated cardiac damage to AF and/or DM.
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Affiliation(s)
- Ana Lorenzo-Almorós
- Internal Medicine Department, Hospital General Universitario Gregorio Marañón, 28007 Madrid, Spain
- Department of Medicine, School of Medicine, Universidad Complutense de Madrid, 28007 Madrid, Spain
| | - Jesús Casado Cerrada
- Internal Medicine Department, Hospital Universitario de Getafe, 28095 Madrid, Spain
| | - Luis-Antonio Álvarez-Sala Walther
- Internal Medicine Department, Hospital General Universitario Gregorio Marañón, 28007 Madrid, Spain
- Department of Medicine, School of Medicine, Universidad Complutense de Madrid, 28007 Madrid, Spain
| | - Manuel Méndez Bailón
- Internal Medicine Department, Hospital Universitario Clinico San Carlos, 28040 Madrid, Spain
| | - Óscar Lorenzo González
- Laboratory of Diabetes and Vascular Pathology, Instituto de Investigaciones Sanitarias-Fundación Jiménez Díaz, Universidad Autónoma, 28040 Madrid, Spain
- Biomedical Research Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM) Network, 28040 Madrid, Spain
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2
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Xu CH, Xiong F, Jiang WF, Liu X, Liu T, Qin M. Rotor mechanism and its mapping in atrial fibrillation. Europace 2023; 25:783-792. [PMID: 36734272 PMCID: PMC10062333 DOI: 10.1093/europace/euad002] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Accepted: 12/28/2022] [Indexed: 02/04/2023] Open
Abstract
Treatment of atrial fibrillation (AF) remains challenging despite significant progress in understanding its underlying mechanisms. The first detailed, quantitative theory of functional re-entry, the 'leading circle' model, was developed more than 40 years ago. Subsequently, in decades of study, an alternative paradigm based on spiral waves has long been postulated to drive AF. The rotor as a 'spiral wave generator' is a curved 'vortex' formed by spin motion in the two-dimensional plane, identified using advanced mapping methods in experimental and clinical AF. However, it is challenging to achieve complementary results between experimental results and clinical studies due to the limitation in research methods and the complexity of the rotor mechanism. Here, we review knowledge garnered over decades on generation, electrophysiological properties, and three-dimensional (3D) structure diversity of the rotor mechanism and make a comparison among recent clinical approaches to identify rotors. Although initial studies of rotor ablation at many independent centres have achieved promising results, some inconclusive outcomes exist in others. We propose that the clinical rotor identification might be substantially influenced by (i) non-identical surface activation patterns, which resulted from a diverse 3D form of scroll wave, and (ii) inadequate resolution of mapping techniques. With rapidly advancing theoretical and technological developments, future work is required to resolve clinically relevant limitations in current basic and clinical research methodology, translate from one to the other, and resolve available mapping techniques.
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Affiliation(s)
- Chang-Hao Xu
- Department of Cardiology, Shanghai Chest Hospital, School of Medicine,
Shanghai Jiao Tong University, 241 Huaihai West Road, Xuhui
District, Shanghai 200030, China
| | - Feng Xiong
- Montreal Heart Institute, Department of Medicine, University of
Montreal, 5000, Bélanger street, Montréal, Québec H1T
1C8, Canada
| | - Wei-Feng Jiang
- Department of Cardiology, Shanghai Chest Hospital, School of Medicine,
Shanghai Jiao Tong University, 241 Huaihai West Road, Xuhui
District, Shanghai 200030, China
| | - Xu Liu
- Department of Cardiology, Shanghai Chest Hospital, School of Medicine,
Shanghai Jiao Tong University, 241 Huaihai West Road, Xuhui
District, Shanghai 200030, China
| | - Tao Liu
- Corresponding authors. Tao Liu, 238 Jiefang Road, Wuchang
District, Wuhan, Hubei 430060, China. Tel: +86 (027) 8804 1911, Fax:+86-(027)-8804-2292.
E-mail address:; Mu Qin, 241 Huaihai
West Road, Xuhui District, Shanghai, 200030, China. Tel: +8621628219902603, Fax:
+862162821105. E-mail address:
| | - Mu Qin
- Corresponding authors. Tao Liu, 238 Jiefang Road, Wuchang
District, Wuhan, Hubei 430060, China. Tel: +86 (027) 8804 1911, Fax:+86-(027)-8804-2292.
E-mail address:; Mu Qin, 241 Huaihai
West Road, Xuhui District, Shanghai, 200030, China. Tel: +8621628219902603, Fax:
+862162821105. E-mail address:
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3
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Rotor hypothesis in the time chain of atrial fibrillation. JOURNAL OF GERIATRIC CARDIOLOGY : JGC 2022; 19:251-253. [PMID: 35572219 PMCID: PMC9068591 DOI: 10.11909/j.issn.1671-5411.2022.04.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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4
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Sanchez de la Nava AM, Arenal Á, Fernández-Avilés F, Atienza F. Artificial Intelligence-Driven Algorithm for Drug Effect Prediction on Atrial Fibrillation: An in silico Population of Models Approach. Front Physiol 2021; 12:768468. [PMID: 34938202 PMCID: PMC8685526 DOI: 10.3389/fphys.2021.768468] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 10/27/2021] [Indexed: 12/12/2022] Open
Abstract
Background: Antiarrhythmic drugs are the first-line treatment for atrial fibrillation (AF), but their effect is highly dependent on the characteristics of the patient. Moreover, anatomical variability, and specifically atrial size, have also a strong influence on AF recurrence. Objective: We performed a proof-of-concept study using artificial intelligence (AI) that enabled us to identify proarrhythmic profiles based on pattern identification from in silico simulations. Methods: A population of models consisting of 127 electrophysiological profiles with a variation of nine electrophysiological variables (G Na , I NaK , G K1, G CaL , G Kur , I KCa , [Na] ext , and [K] ext and diffusion) was simulated using the Koivumaki atrial model on square planes corresponding to a normal (16 cm2) and dilated (22.5 cm2) atrium. The simple pore channel equation was used for drug implementation including three drugs (isoproterenol, flecainide, and verapamil). We analyzed the effect of every ionic channel combination to evaluate arrhythmia induction. A Random Forest algorithm was trained using the population of models and AF inducibility as input and output, respectively. The algorithm was trained with 80% of the data (N = 832) and 20% of the data was used for testing with a k-fold cross-validation (k = 5). Results: We found two electrophysiological patterns derived from the AI algorithm that was associated with proarrhythmic behavior in most of the profiles, where G K1 was identified as the most important current for classifying the proarrhythmicity of a given profile. Additionally, we found different effects of the drugs depending on the electrophysiological profile and a higher tendency of the dilated tissue to fibrillate (Small tissue: 80 profiles vs Dilated tissue: 87 profiles). Conclusion: Artificial intelligence algorithms appear as a novel tool for electrophysiological pattern identification and analysis of the effect of antiarrhythmic drugs on a heterogeneous population of patients with AF.
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Affiliation(s)
- Ana Maria Sanchez de la Nava
- Department of Cardiology, Hospital General Universitario Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón (IISGM), Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain.,ITACA Institute, Universitat Politécnica de València, València, Spain
| | - Ángel Arenal
- Department of Cardiology, Hospital General Universitario Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón (IISGM), Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain.,Facultad de Medicina, Universidad Complutense de Madrid, Madrid, Spain
| | - Francisco Fernández-Avilés
- Department of Cardiology, Hospital General Universitario Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón (IISGM), Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain.,Facultad de Medicina, Universidad Complutense de Madrid, Madrid, Spain
| | - Felipe Atienza
- Department of Cardiology, Hospital General Universitario Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón (IISGM), Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain.,Facultad de Medicina, Universidad Complutense de Madrid, Madrid, Spain
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5
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Zhang S, Lu W, Wei Z, Zhang H. Air Pollution and Cardiac Arrhythmias: From Epidemiological and Clinical Evidences to Cellular Electrophysiological Mechanisms. Front Cardiovasc Med 2021; 8:736151. [PMID: 34778399 PMCID: PMC8581215 DOI: 10.3389/fcvm.2021.736151] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Accepted: 10/04/2021] [Indexed: 01/08/2023] Open
Abstract
Cardiovascular disease is the leading cause of death worldwide and kills over 17 million people per year. In the recent decade, growing epidemiological evidence links air pollution and cardiac arrhythmias, suggesting a detrimental influence of air pollution on cardiac electrophysiological functionality. However, the proarrhythmic mechanisms underlying the air pollution-induced cardiac arrhythmias are not fully understood. The purpose of this work is to provide recent advances in air pollution-induced arrhythmias with a comprehensive review of the literature on the common air pollutants and arrhythmias. Six common air pollutants of widespread concern are discussed, namely particulate matter, carbon monoxide, hydrogen sulfide, sulfur dioxide, nitrogen dioxide, and ozone. The epidemiological and clinical reports in recent years are reviewed by pollutant type, and the recently identified mechanisms including both the general pathways and the direct influences of air pollutants on the cellular electrophysiology are summarized. Particularly, this review focuses on the impaired ion channel functionality underlying the air pollution-induced arrhythmias. Alterations of ionic currents directly by the air pollutants, as well as the alterations mediated by intracellular signaling or other more general pathways are reviewed in this work. Finally, areas for future research are suggested to address several remaining scientific questions.
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Affiliation(s)
- Shugang Zhang
- Computational Cardiology Group, College of Computer Science and Technology, Ocean University of China, Qingdao, China.,Biological Physics Group, School of Physics and Astronomy, University of Manchester, Manchester, United Kingdom
| | - Weigang Lu
- Computational Cardiology Group, College of Computer Science and Technology, Ocean University of China, Qingdao, China.,Biological Physics Group, School of Physics and Astronomy, University of Manchester, Manchester, United Kingdom
| | - Zhiqiang Wei
- Computational Cardiology Group, College of Computer Science and Technology, Ocean University of China, Qingdao, China
| | - Henggui Zhang
- Biological Physics Group, School of Physics and Astronomy, University of Manchester, Manchester, United Kingdom
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6
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Zhang L, Wang X, Huang C. A narrative review of non-coding RNAs in atrial fibrillation: potential therapeutic targets and molecular mechanisms. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:1486. [PMID: 34734038 PMCID: PMC8506732 DOI: 10.21037/atm-21-4483] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 09/16/2021] [Indexed: 11/11/2022]
Abstract
Objective This review summarizes the advances in the study of ncRNAs and atrial remodeling mechanisms to explore potential therapeutic targets and strategies for AF. Background Atrial fibrillation (AF) is one of the most common arrhythmias, and its morbidity and mortality rates are gradually increasing. Non-coding ribonucleic acid RNAs (ncRNAs) are transcribed from the genome and do not have the ability to be translated into proteins. A growing body of evidence has shown ncRNAs are extensively involved in the pathophysiological processes underlying AF. However, the precise molecular mechanisms of these associations have not been fully elucidated. Atrial remodeling plays a key role in the occurrence and development of AF, and includes electrical remodeling, structural remodeling, and autonomic nerve remodeling. Research has shown that ncRNA expression is altered in the plasma and tissues of AF patients that mediate cardiac excitation and arrhythmia, and is closely related to atrial remodeling. Methods Literatures about ncRNAs and atrial fibrillation were extensively reviewed to discuss and analyze. Conclusions The biology of ncRNAs represents a relatively new field of research and is still in an emerging stage. Recent studies have laid a foundation for understanding the molecular mechanisms of AF, future studies aimed at identifying how ncRNAs act on atrial fibrillation to provide potentially promising therapeutic targets for the treatment of atrial fibrillation.
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Affiliation(s)
- Lan Zhang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China.,Cardiovascular Research Institute, Wuhan University, Wuhan, China.,Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Xi Wang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China.,Cardiovascular Research Institute, Wuhan University, Wuhan, China.,Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Congxin Huang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China.,Cardiovascular Research Institute, Wuhan University, Wuhan, China.,Hubei Key Laboratory of Cardiology, Wuhan, China
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7
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Quah JX, Dharmaprani D, Lahiri A, Tiver K, Ganesan AN. Reconceptualising Atrial Fibrillation Using Renewal Theory: A Novel Approach to the Assessment of Atrial Fibrillation Dynamics. Arrhythm Electrophysiol Rev 2021; 10:77-84. [PMID: 34401179 PMCID: PMC8335853 DOI: 10.15420/aer.2020.42] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Accepted: 02/03/2021] [Indexed: 11/15/2022] Open
Abstract
Despite a century of research, the mechanisms of AF remain unresolved. A universal motif within AF research has been unstable re-entry, but this remains poorly characterised, with competing key conceptual paradigms of multiple wavelets and more driving rotors. Understanding the mechanisms of AF is clinically relevant, especially with regard to treatment and ablation of the more persistent forms of AF. Here, the authors outline the surprising but reproducible finding that unstable re-entrant circuits are born and destroyed at quasi-stationary rates, a finding based on a branch of mathematics known as renewal theory. Renewal theory may be a way to potentially unify the multiple wavelet and rotor theories. The renewal rate constants are potentially attractive because they are temporally stable parameters of a defined probability distribution (the exponential distribution) and can be estimated with precision and accuracy due to the principles of renewal theory. In this perspective review, this new representational architecture for AF is explained and placed into context, and the clinical and mechanistic implications are discussed.
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Affiliation(s)
- Jing Xian Quah
- College of Medicine and Public Health, Flinders University of South Australia, Adelaide, SA, Australia.,Department of Cardiovascular Medicine, Flinders Medical Centre, Adelaide, SA, Australia
| | - Dhani Dharmaprani
- College of Medicine and Public Health, Flinders University of South Australia, Adelaide, SA, Australia.,College of Science and Engineering, Flinders University of South Australia, Adelaide, SA, Australia
| | - Anandaroop Lahiri
- Department of Cardiovascular Medicine, Flinders Medical Centre, Adelaide, SA, Australia
| | - Kathryn Tiver
- College of Medicine and Public Health, Flinders University of South Australia, Adelaide, SA, Australia.,Department of Cardiovascular Medicine, Flinders Medical Centre, Adelaide, SA, Australia
| | - Anand N Ganesan
- College of Medicine and Public Health, Flinders University of South Australia, Adelaide, SA, Australia.,Department of Cardiovascular Medicine, Flinders Medical Centre, Adelaide, SA, Australia
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8
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The Electrophysiology of Atrial Fibrillation: From Basic Mechanisms to Catheter Ablation. Cardiol Res Pract 2021; 2021:4109269. [PMID: 34194824 PMCID: PMC8203364 DOI: 10.1155/2021/4109269] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 04/11/2021] [Accepted: 05/27/2021] [Indexed: 11/17/2022] Open
Abstract
The electrophysiology of atrial fibrillation (AF) has always been a deep mystery in understanding this complex arrhythmia. The pathophysiological mechanisms of AF are complex and often remain unclear despite extensive research. Therefore, the implementation of basic science knowledge to clinical practice is challenging. After more than 20 years, pulmonary vein isolation (PVI) remains the cornerstone ablation strategy for maintaining the sinus rhythm (SR). However, there is no doubt that, in many cases, especially in persistent and long-standing persistent AF, PVI is not enough, and eventually, the restoration of SR occurs after additional intervention in the rest of the atrial myocardium. Substrate mapping is a modern challenge as it can reveal focal sources or rotational activities that may be responsible for maintaining AF. Whether these areas are actually the cause of the AF maintenance is unknown. If this really happens, then the targeted ablation may be the solution; otherwise, more rough techniques such as atrial compartmentalization may prove to be more effective. In this article, we attempt a broad review of the known pathophysiological mechanisms of AF, and we present the recent efforts of advanced technology initially to reveal the electrical impulse during AF and then to intervene effectively with ablation.
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9
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Quah JX, Dharmaprani D, Tiver K, Lahiri A, Hecker T, Perry R, Selvanayagam JB, Joseph MX, McGavigan A, Ganesan A. Atrial fibrosis and substrate based characterization in atrial fibrillation: Time to move forwards. J Cardiovasc Electrophysiol 2021; 32:1147-1160. [PMID: 33682258 DOI: 10.1111/jce.14987] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 02/15/2021] [Accepted: 02/22/2021] [Indexed: 12/15/2022]
Abstract
Atrial fibrillation (AF) is the most commonly encountered cardiac arrhythmia in clinical practice. However, current therapeutic interventions for atrial fibrillation have limited clinical efficacy as a consequence of major knowledge gaps in the mechanisms sustaining atrial fibrillation. From a mechanistic perspective, there is increasing evidence that atrial fibrosis plays a central role in the maintenance and perpetuation of atrial fibrillation. Electrophysiologically, atrial fibrosis results in alterations in conduction velocity, cellular refractoriness, and produces conduction block promoting meandering, unstable wavelets and micro-reentrant circuits. Clinically, atrial fibrosis has also linked to poor clinical outcomes including AF-related thromboembolic complications and arrhythmia recurrences post catheter ablation. In this article, we review the pathophysiology behind the formation of fibrosis as AF progresses, the role of fibrosis in arrhythmogenesis, surrogate markers for detection of fibrosis using cardiac magnetic resonance imaging, echocardiography and electroanatomic mapping, along with their respective limitations. We then proceed to review the current evidence behind therapeutic interventions targeting atrial fibrosis, including drugs and substrate-based catheter ablation therapies followed by the potential future use of electro phenotyping for AF characterization to overcome the limitations of contemporary substrate-based methodologies.
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Affiliation(s)
- Jing X Quah
- College of Medicine and Public Health, Flinders University of South Australia, Adelaide, Australia.,Department of Cardiovascular Medicine, Flinders Medical Centre, Adelaide, Australia
| | - Dhani Dharmaprani
- College of Medicine and Public Health, Flinders University of South Australia, Adelaide, Australia.,College of Science and Engineering, Flinders University of South Australia, Adelaide, Australia
| | - Kathryn Tiver
- Department of Cardiovascular Medicine, Flinders Medical Centre, Adelaide, Australia
| | - Anandaroop Lahiri
- Department of Cardiovascular Medicine, Flinders Medical Centre, Adelaide, Australia
| | - Teresa Hecker
- Department of Cardiovascular Medicine, Flinders Medical Centre, Adelaide, Australia
| | - Rebecca Perry
- Department of Cardiovascular Medicine, Flinders Medical Centre, Adelaide, Australia.,UniSA Allied Health and Human Performance, University of South Australia, Adelaide, Australia
| | | | - Majo X Joseph
- Department of Cardiovascular Medicine, Flinders Medical Centre, Adelaide, Australia
| | | | - Anand Ganesan
- College of Medicine and Public Health, Flinders University of South Australia, Adelaide, Australia.,Department of Cardiovascular Medicine, Flinders Medical Centre, Adelaide, Australia
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10
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Meng T, Wang J, Tang M, Liu S, Ding L, Yan Y. Diabetes Mellitus Promotes Atrial Structural Remodeling and PARP-1/Ikkα/NF-κB Pathway Activation in Mice. Diabetes Metab Syndr Obes 2021; 14:2189-2199. [PMID: 34040405 PMCID: PMC8139946 DOI: 10.2147/dmso.s300616] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 04/02/2021] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND Diabetes mellitus (DM) has been demonstrated to be linked to atrial fibrillation (AF). However, the underlying mechanisms of the DM-associated increase in AF susceptibility and the potential effects of DM on atrial remodeling remain unclear. METHODS AND RESULTS Twenty-five C57BL/6 mice were randomly assigned to the normal/control group (Con, n=10) and model group (n=15). Mice in the model group were administered a high-fat diet combined with multiple injections of low-dose streptozocin (STZ) (35 mg/kg). Eleven mice were ultimately included in DM group. Left atrial tissue structural and inflammatory alterations were assessed. In our study, the atrial weights of DM mice were markedly heavier than those of mice in the Con group. DM mice exhibited significantly increased fasting plasma glucose, fasting insulin, and dyslipidaemia. Furthermore, H&E and Masson's staining revealed broadened interstitial spaces, myocyte disarray and atrial fibrosis in DM mice. The expression levels of the atrial inflammation-associated factor nuclear factor κB (NF-κB) and its pathway were significantly altered in the atria of DM mice. CONCLUSION DM could induce atrial structural remodeling and inflammation in mice.
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Affiliation(s)
- Tianyu Meng
- Department of Geriatrics, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi, 710061, People’s Republic of China
| | - Jie Wang
- Department of Cardiovascular Medicine, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi, 710061, People’s Republic of China
- Department of Hematology, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi, 710061, People’s Republic of China
| | - Manyun Tang
- Department of Cardiovascular Medicine, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi, 710061, People’s Republic of China
| | - Shangyu Liu
- Clinical EP Lab & Arrhythmia Center, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100037, People’s Republic of China
| | - Ligang Ding
- Clinical EP Lab & Arrhythmia Center, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100037, People’s Republic of China
- Correspondence: Ligang Ding Clinical EP Lab & Arrhythmia Center, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100037, People’s Republic of China Email
| | - Yang Yan
- Department of Cardiovascular Surgery, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi, 710061, People’s Republic of China
- Yang Yan Department of Cardiovascular Surgery, The First Affiliated Hospital of Xi’an Jiaotong University, No. 277 Yanta West Road, Xi’an, Shaanxi, 710061, People’s Republic of ChinaTel +86-2985323869Fax +86-2985323869 Email
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11
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Mannion J, Galvin J, Boles U. Left atrial scar identification and quantification in sinus rhythm and atrial fibrillation. J Arrhythm 2020; 36:967-973. [PMID: 33335611 PMCID: PMC7733578 DOI: 10.1002/joa3.12421] [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: 03/23/2020] [Revised: 07/20/2020] [Accepted: 08/10/2020] [Indexed: 11/30/2022] Open
Abstract
Identification and quantification of low voltage areas (LVA) in atrial fibrillation (AF), identified by their bipolar voltages (BiV) via electro-anatomical voltage mapping is an area of interest to prognosis of AF free burden. LVAs have been linked to diseased left atrial (LA) tissue which results in pro-fibrillatory potentials. These LVAs are dominantly found within the pulmonary veins, however, as the disease progresses other areas of the LA show low voltage. The scar burden of the LA is linked to recurrence of the arrhythmia and can be a target of further modification. This burden is classically assessed once sinus rhythm (SR) is attained, but this is susceptible to operator variability with overestimated dense LA scar (<0.2 mV) and underestimated diseased LA tissue (<0.5 mV). The novel automated voltage histogram analysis (VHA) tool may increase accuracy, however, is yet to be fully validated. A recent study indicates that LVAs can be assessed just as reliably in AF as SR, but BiV is lower with linear correlation to SR values (0.24-0.5 mV respectively). In this paper, we review current data as well as review current methods of identifying, quantifying, and grading LA scar. We also compared AF vs SR voltages of a patient undergoing catheter ablation in our site using our VHA tool to compare the results. In keeping with the cited papers, we found lower voltages in our patient measured in AF. This area warrants further study to assess correlation in more patients, with view to developing prognostic and therapeutic grading systems.
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Affiliation(s)
- James Mannion
- Cardiology Department, Heart and Vascular CentreMater Private HospitalDublinIreland
| | - Joseph Galvin
- Cardiology Department, Heart and Vascular CentreMater Private HospitalDublinIreland
| | - Usama Boles
- Cardiology Department, Heart and Vascular CentreMater Private HospitalDublinIreland
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12
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Fenger-Grøn M, Vinter N, Frost L. Body mass and atrial fibrillation risk: Status of the epidemiology concerning the influence of fat versus lean body mass. Trends Cardiovasc Med 2020; 30:205-211. [DOI: 10.1016/j.tcm.2019.05.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 05/20/2019] [Accepted: 05/27/2019] [Indexed: 12/29/2022]
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13
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Gagné S, Jacquemet V. Time resolution for wavefront and phase singularity tracking using activation maps in cardiac propagation models. CHAOS (WOODBURY, N.Y.) 2020; 30:033132. [PMID: 32237790 DOI: 10.1063/1.5133077] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 03/02/2020] [Indexed: 06/11/2023]
Abstract
The dynamics of cardiac fibrillation can be described by the number, the trajectory, the stability, and the lifespan of phase singularities (PSs). Accurate PS tracking is straightforward in simple uniform tissues but becomes more challenging as fibrosis, structural heterogeneity, and strong anisotropy are combined. In this paper, we derive a mathematical formulation for PS tracking in two-dimensional reaction-diffusion models. The method simultaneously tracks wavefronts and PS based on activation maps at full spatiotemporal resolution. PS tracking is formulated as a linear assignment problem solved by the Hungarian algorithm. The cost matrix incorporates information about distances between PS, chirality, and wavefronts. A graph of PS trajectories is generated to represent the creations and annihilations of PS pairs. Structure-preserving graph transformations are applied to provide a simplified description at longer observation time scales. The approach is validated in 180 simulations of fibrillation in four different types of substrates featuring, respectively, wavebreaks, ionic heterogeneities, fibrosis, and breakthrough patterns. The time step of PS tracking is studied in the range from 0.1 to 10 ms. The results show the benefits of improving time resolution from 1 to 0.1 ms. The tracking error rate decreases by an order of magnitude because the occurrence of simultaneous events becomes less likely. As observed on PS survival curves, the graph-based analysis facilitates the identification of macroscopically stable rotors despite wavefront fragmentation by fibrosis.
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Affiliation(s)
- Samuel Gagné
- Institut de Génie Biomédical, Département de Pharmacologie et Physiologie, Université de Montréal, C.P. 6128, succursale Centre-ville, Montréal, Quebec H3C 3J7, Canada
| | - Vincent Jacquemet
- Institut de Génie Biomédical, Département de Pharmacologie et Physiologie, Université de Montréal, C.P. 6128, succursale Centre-ville, Montréal, Quebec H3C 3J7, Canada
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Abstract
Hypertension is the most common cardiovascular risk factor and underlies heart failure, coronary artery disease, stroke, and chronic kidney disease. Hypertensive heart disease can manifest as cardiac arrhythmias. Supraventricular and ventricular arrhythmias may occur in the hypertensive patients. Atrial fibrillation and hypertension contribute to an increased risk of stroke. Some antihypertensive drugs predispose to electrolyte abnormalities, which may result in atrial and ventricular arrhythmias. A multipronged strategy involving appropriate screening, aggressive lifestyle modifications, and optimal pharmacotherapy can result in improved blood pressure control and prevent the onset or delay progression of heart failure, coronary artery disease, and cardiac arrhythmias.
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Affiliation(s)
- Muhammad R Afzal
- Division of Cardiovascular Medicine, The Ohio State University Wexner Medical Center, 473 West 12th Avenue, Suite 200, Columbus, OH 43210, USA
| | - Salvatore Savona
- Division of Cardiovascular Medicine, The Ohio State University Wexner Medical Center, 473 West 12th Avenue, Suite 200, Columbus, OH 43210, USA
| | - Omar Mohamed
- Division of Cardiovascular Medicine, The Ohio State University Wexner Medical Center, 473 West 12th Avenue, Suite 200, Columbus, OH 43210, USA
| | - Aayah Mohamed-Osman
- Division of Cardiovascular Medicine, The Ohio State University Wexner Medical Center, 473 West 12th Avenue, Suite 200, Columbus, OH 43210, USA
| | - Steven J Kalbfleisch
- Division of Cardiovascular Medicine, The Ohio State University Wexner Medical Center, 473 West 12th Avenue, Suite 200, Columbus, OH 43210, USA.
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Borger MA, Mansour MC, Levine RA. Atrial Fibrillation and Mitral Valve Prolapse: Time to Intervene? J Am Coll Cardiol 2019; 73:275-277. [PMID: 30678756 DOI: 10.1016/j.jacc.2018.11.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 11/09/2018] [Indexed: 10/27/2022]
Affiliation(s)
- Michael A Borger
- University Clinic for Cardiac Surgery, Leipzig Heart Center, Leipzig, Germany.
| | - Moussa C Mansour
- Cardiology Division, Massachusetts General Hospital, Boston, Massachusetts
| | - Robert A Levine
- Cardiology Division, Massachusetts General Hospital, Boston, Massachusetts
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17
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Lupercio F, Lin AY, Aldaas OM, Romero J, Briceno D, Hoffmayer KS, Han FT, Di Biase L, Feld GK, Hsu JC. Role of adjunctive posterior wall isolation in patients undergoing atrial fibrillation ablation: a systematic review and meta-analysis. J Interv Card Electrophysiol 2019; 58:77-86. [DOI: 10.1007/s10840-019-00634-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 09/24/2019] [Indexed: 10/25/2022]
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Tirapu L, San Antonio R, Tolosana JM, Roca-Luque I, Mont L, Guasch E. Exercise and atrial fibrillation: how health turns harm, and how to turn it back. Minerva Cardioangiol 2019; 67:411-424. [DOI: 10.23736/s0026-4725.19.04998-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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19
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D’Souza A, Trussell T, Morris GM, Dobrzynski H, Boyett MR. Supraventricular Arrhythmias in Athletes: Basic Mechanisms and New Directions. Physiology (Bethesda) 2019; 34:314-326. [DOI: 10.1152/physiol.00009.2019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Athletes are prone to supraventricular rhythm disturbances including sinus bradycardia, heart block, and atrial fibrillation. Mechanistically, this is attributed to high vagal tone and cardiac electrical and structural remodeling. Here, we consider the supporting evidence for these three pro-arrhythmic mechanisms in athletic human cohorts and animal models, featuring current controversies, emerging data, and future directions of relevance to the translational research agenda.
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Affiliation(s)
- Alicia D’Souza
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Tariq Trussell
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Gwilym M. Morris
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Halina Dobrzynski
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Mark R. Boyett
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
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Filos D, Tachmatzidis D, Maglaveras N, Vassilikos V, Chouvarda I. Understanding the Beat-to-Beat Variations of P-Waves Morphologies in AF Patients During Sinus Rhythm: A Scoping Review of the Atrial Simulation Studies. Front Physiol 2019; 10:742. [PMID: 31275161 PMCID: PMC6591370 DOI: 10.3389/fphys.2019.00742] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 05/28/2019] [Indexed: 11/13/2022] Open
Abstract
The remarkable advances in high-performance computing and the resulting increase of the computational power have the potential to leverage computational cardiology toward improving our understanding of the pathophysiological mechanisms of arrhythmias, such as Atrial Fibrillation (AF). In AF, a complex interaction between various triggers and the atrial substrate is considered to be the leading cause of AF initiation and perpetuation. In electrocardiography (ECG), P-wave is supposed to reflect atrial depolarization. It has been found that even during sinus rhythm (SR), multiple P-wave morphologies are present in AF patients with a history of AF, suggesting a higher dispersion of the conduction route in this population. In this scoping review, we focused on the mechanisms which modify the electrical substrate of the atria in AF patients, while investigating the existence of computational models that simulate the propagation of the electrical signal through different routes. The adopted review methodology is based on a structured analytical framework which includes the extraction of the keywords based on an initial limited bibliographic search, the extensive literature search and finally the identification of relevant articles based on the reference list of the studies. The leading mechanisms identified were classified according to their scale, spanning from mechanisms in the cell, tissue or organ level, and the produced outputs. The computational modeling approaches for each of the factors that influence the initiation and the perpetuation of AF are presented here to provide a clear overview of the existing literature. Several levels of categorization were adopted while the studies which aim to translate their findings to ECG phenotyping are highlighted. The results denote the availability of multiple models, which are appropriate under specific conditions. However, the consideration of complex scenarios taking into account multiple spatiotemporal scales, personalization of electrophysiological and anatomical models and the reproducibility in terms of ECG phenotyping has only partially been tackled so far.
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Affiliation(s)
- Dimitrios Filos
- Lab of Computing, Medical Informatics and Biomedical Imaging Technologies, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | | | - Nicos Maglaveras
- Lab of Computing, Medical Informatics and Biomedical Imaging Technologies, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece
- Department of Industrial Engineering and Management Sciences, Northwestern University, Evanston, IL, United States
| | - Vassilios Vassilikos
- 3rd Cardiology Department, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Ioanna Chouvarda
- Lab of Computing, Medical Informatics and Biomedical Imaging Technologies, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece
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Alzahrani T, McCaffrey J, Mercader M, Solomon A. Rate Versus Rhythm Control in Patients with Normal to Mild Left Atrial Enlargement: Insights from the AFFIRM Trial. J Atr Fibrillation 2019; 11:2067. [PMID: 31139272 DOI: 10.4022/jafib.2067] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2017] [Revised: 08/19/2017] [Accepted: 09/14/2017] [Indexed: 12/19/2022]
Abstract
Background Atrial fibrillation is the most commonly encountered sustained arrhythmia and is associated with significant morbidity and mortality. Several trials have demonstrated that no mortality benefit exists when choosing a rhythm-control strategy over a rate-control strategy, with some trials suggesting an increase in mortality. Using the AFFIRM trial database we sought to determine the effect of rhythm control strategy in patients with normal or mild atrial enlargement. Methods AFFIRM Trial database was used to evaluate the effect of rhythm-control strategy compared to rate-control strategy in a subgroup of patients with normal to mild left atrial (LA) enlargement. The primary outcome measures of this study were all-cause mortality, cardiovascular mortality, non-cardiovascular mortality, and hospitalization/ED visit. Results We identified a subgroup of subjects from the AFFIRM trial with normal or mild LA enlargement (n=2022 of 4060 total subjects). Subjects in the rhythm-control group(n= 1022) had an increased risk of all-cause mortality by 34% (RR 1.34, 95% CI 1.08-1.67; P=0.007) and hospitalization/ED visits by 10% (RR 1.10, 95% CI 1.05-2.16; P=<0.001) compared to rate control group(n= 1000). Conclusion This study demonstrated that rhythm-control strategy increases the risk of mortality and hospitalization in a subgroup of patients with normal to mild atrial enlargement compared to rate-control strategy. Amiodarone use in this subgroup of patients likely drove these findings.
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Affiliation(s)
- Talal Alzahrani
- Division of Cardiology, Department of Medicine, George Washington University, Washington, DC
| | - James McCaffrey
- Division of Cardiology, Department of Medicine, George Washington University, Washington, DC
| | - Marco Mercader
- Division of Cardiology, Department of Medicine, George Washington University, Washington, DC
| | - Allen Solomon
- Division of Cardiology, Department of Medicine, George Washington University, Washington, DC
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22
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Nattel S. Atrial Fibrillation and Body Composition: Is it Fat or Lean That Ultimately Determines the Risk? J Am Coll Cardiol 2019; 69:2498-2501. [PMID: 28521887 DOI: 10.1016/j.jacc.2017.03.566] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 03/21/2017] [Indexed: 11/24/2022]
Affiliation(s)
- Stanley Nattel
- Department of Medicine, Montreal Heart Institute and Université de Montréal, Montréal, Quebec, Canada; Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada; Institute of Pharmacology, West German Heart and Vascular Center, Faculty of Medicine, University Duisburg-Essen, Essen, Germany.
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23
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Denham NC, Pearman CM, Caldwell JL, Madders GWP, Eisner DA, Trafford AW, Dibb KM. Calcium in the Pathophysiology of Atrial Fibrillation and Heart Failure. Front Physiol 2018; 9:1380. [PMID: 30337881 PMCID: PMC6180171 DOI: 10.3389/fphys.2018.01380] [Citation(s) in RCA: 96] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 09/11/2018] [Indexed: 12/20/2022] Open
Abstract
Atrial fibrillation (AF) is commonly associated with heart failure. A bidirectional relationship exists between the two-AF exacerbates heart failure causing a significant increase in heart failure symptoms, admissions to hospital and cardiovascular death, while pathological remodeling of the atria as a result of heart failure increases the risk of AF. A comprehensive understanding of the pathophysiology of AF is essential if we are to break this vicious circle. In this review, the latest evidence will be presented showing a fundamental role for calcium in both the induction and maintenance of AF. After outlining atrial electrophysiology and calcium handling, the role of calcium-dependent afterdepolarizations and atrial repolarization alternans in triggering AF will be considered. The atrial response to rapid stimulation will be discussed, including the short-term protection from calcium overload in the form of calcium signaling silencing and the eventual progression to diastolic calcium leak causing afterdepolarizations and the development of an electrical substrate that perpetuates AF. The role of calcium in the bidirectional relationship between heart failure and AF will then be covered. The effects of heart failure on atrial calcium handling that promote AF will be reviewed, including effects on both atrial myocytes and the pulmonary veins, before the aspects of AF which exacerbate heart failure are discussed. Finally, the limitations of human and animal studies will be explored allowing contextualization of what are sometimes discordant results.
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Affiliation(s)
- Nathan C. Denham
- Unit of Cardiac Physiology, Division of Cardiovascular Sciences, Manchester Academic Health Science Centre, University of Manchester, Manchester, United Kingdom
| | | | | | | | | | | | - Katharine M. Dibb
- Unit of Cardiac Physiology, Division of Cardiovascular Sciences, Manchester Academic Health Science Centre, University of Manchester, Manchester, United Kingdom
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Saha M, Roney CH, Bayer JD, Meo M, Cochet H, Dubois R, Vigmond EJ. Wavelength and Fibrosis Affect Phase Singularity Locations During Atrial Fibrillation. Front Physiol 2018; 9:1207. [PMID: 30246796 PMCID: PMC6139329 DOI: 10.3389/fphys.2018.01207] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 08/10/2018] [Indexed: 01/06/2023] Open
Abstract
The mechanisms underlying atrial fibrillation (AF), the most common sustained cardiac rhythm disturbance, remain elusive. Atrial fibrosis plays an important role in the development of AF and rotor dynamics. Both electrical wavelength (WL) and the degree of atrial fibrosis change as AF progresses. However, their combined effect on rotor core location remains unknown. The aim of this study was to analyze the effects of WL change on rotor core location in both fibrotic and non-fibrotic atria. Three patient specific fibrosis distributions (total fibrosis content: 16.6, 22.8, and 19.2%) obtained from clinical imaging data of persistent AF patients were incorporated in a bilayer atrial computational model. Fibrotic effects were modeled as myocyte-fibroblast coupling + conductivity remodeling; structural remodeling; ionic current changes + conductivity remodeling; and combinations of these methods. To change WL, action potential duration (APD) was varied from 120 to 240ms, representing the range of clinically observed AF cycle length, by modifying the inward rectifier potassium current (IK1) conductance between 80 and 140% of the original value. Phase singularities (PSs) were computed to identify rotor core locations. Our results show that IK1 conductance variation resulted in a decrease of APD and WL across the atria. For large WL in the absence of fibrosis, PSs anchored to regions with high APD gradient at the center of the left atrium (LA) anterior wall and near the junctions of the inferior pulmonary veins (PVs) with the LA. Decreasing the WL induced more PSs, whose distribution became less clustered. With fibrosis, PS locations depended on the fibrosis distribution and the fibrosis implementation method. The proportion of PSs in fibrotic areas and along the borders varied with both WL and fibrosis modeling method: for patient one, this was 4.2-14.9% as IK1 varied for the structural remodeling representation, but 12.3-88.4% using the combination of structural remodeling with myocyte-fibroblast coupling. The degree and distribution of fibrosis and the choice of implementation technique had a larger effect on PS locations than the WL variation. Thus, distinguishing the fibrotic mechanisms present in a patient is important for interpreting clinical fibrosis maps to create personalized models.
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Affiliation(s)
- Mirabeau Saha
- IMB, UMR 5251, University of Bordeaux, Pessac, France
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux University, Pessac, France
| | - Caroline H. Roney
- Department of Biomedical Engineering, King's College London, London, United Kingdom
| | - Jason D. Bayer
- IMB, UMR 5251, University of Bordeaux, Pessac, France
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux University, Pessac, France
| | - Marianna Meo
- IMB, UMR 5251, University of Bordeaux, Pessac, France
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux University, Pessac, France
| | - Hubert Cochet
- IMB, UMR 5251, University of Bordeaux, Pessac, France
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux University, Pessac, France
| | - Remi Dubois
- IMB, UMR 5251, University of Bordeaux, Pessac, France
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux University, Pessac, France
| | - Edward J. Vigmond
- IMB, UMR 5251, University of Bordeaux, Pessac, France
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux University, Pessac, France
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25
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Hummel JP, Akar JG, Baher A, Webber CL. New skip parameter to facilitate recurrence quantification of signals comprised of multiple components. CHAOS (WOODBURY, N.Y.) 2018; 28:085718. [PMID: 30180597 DOI: 10.1063/1.5024845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 07/26/2018] [Indexed: 06/08/2023]
Abstract
Recurrence analyses are typically performed on discretized time series after applying proper embeddings, delays, and thresholds. In our study of atrial electrograms, we found limitations to this approach when sequential bipolar complexes were defined as the timings of the first two zero crosses following the initiation of each event. The reason for this is that each bipolar component consists of two points in odd-even pairings. Since recurrence analysis starts vectors on each sequential point, incorrect even-odd pairings occur for every other vector. To overcome this limitation, a new parameter SKIP is introduced such that recurrence vectors can skip 1 (or 2) points for signals with defined multiple components. To demonstrate the utility of parameter SKIP, we used the Courtemanche model to simulate the electrical activity in the human atrium on a square, two-dimensional plane with 800 × 800 nodes. Over this plane, a grid of 39 × 39 virtual unipoles was created. Neighboring unipoles formed 39 × 38 bipolar pairs, which were recorded as 1482 continuous and synchronous time series. At each unipolar site, the actual wavefront direction was determined by comparing the relative activation timings of the local intracellular potentials. Parameters were set such that the "tissue" exhibited both spiral waves (organized activity) and wave breakups (chaotic activity). For each bipolar complex in the continuous electrogram, discretized electrogram conformation was defined as the timing delays from the start of the complex to the first two zero-crosses. Long sequences of paired zero-cross timings were subjected to recurrence analysis using SKIP values of 0 (no skipping) and 1 (single skipping). Recurrence variables were computed and correlated with the absolute wavefront directions. The results showed that the introduction of the skipping window improved the correlations of some recurrence variables with absolute wavefront directions. This is critically important because such variables may be better markers for wavefront directions in human recordings when the absolute wavefront directions cannot be calculated directly.
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Affiliation(s)
- James P Hummel
- Division of Cardiovascular Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53726, USA
| | - Joseph G Akar
- Section of Cardiovascular Medicine, Department of Medicine, Yale University School of Medicine, New Haven, Connecticut 06510, USA
| | - Alex Baher
- Division of Cardiovascular Medicine, School of Medicine, University of Utah Health, Salt Lake City, Utah 84132, USA
| | - Charles L Webber
- Department of Cell and Molecular Physiology, Loyola University Chicago - Health Sciences Division, Maywood, Illinois 60153, USA
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Manninger M, Zweiker D, van Hunnik A, Alogna A, Prassl AJ, Schipke J, Zeemering S, Zirngast B, Schönleitner P, Schwarzl M, Herbst V, Thon-Gutschi E, Huber S, Rohrer U, Ebner J, Brussee H, Pieske BM, Heinzel FR, Verheule S, Antoons G, Lueger A, Mühlfeld C, Plank G, Schotten U, Post H, Scherr D. Arterial hypertension drives arrhythmia progression via specific structural remodeling in a porcine model of atrial fibrillation. Heart Rhythm 2018; 15:1328-1336. [PMID: 29803020 DOI: 10.1016/j.hrthm.2018.05.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Indexed: 11/28/2022]
Abstract
BACKGROUND Arterial hypertension (HT) contributes to progression of atrial fibrillation (AF) via unknown mechanisms. OBJECTIVE We aimed to characterize electrical and structural changes accounting for increased AF stability in a large animal model of rapid atrial pacing (RAP)-induced AF combined with desoxycorticosterone acetate (DOCA)-induced HT. METHODS Eighteen pigs were instrumented with right atrial endocardial pacemaker leads and custom-made pacemakers to induce AF by continuous RAP (600 beats/min). DOCA pellets were subcutaneously implanted in a subgroup of 9 animals (AF+HT group); the other 9 animals served as controls (AF group). Final experiments included electrophysiology studies, endocardial electroanatomic mapping, and high-density mapping with epicardial multielectrode arrays. In addition, 3-dimensional computational modeling was performed. RESULTS DOCA implantation led to secondary HT (median [interquartile range] aortic pressure 109.9 [100-137] mm Hg in AF+HT vs 82.2 [79-96] mm Hg in AF; P < .05), increased AF stability (55.6% vs 12.5% of animals with AF episodes lasting >1 hour; P < .05), concentric left ventricular hypertrophy, atrial dilatation (119 ± 31 cm2 in AF+HT vs 78 ± 23 cm2 in AF; P < .05), and fibrosis. Collagen accumulation in the AF+HT group was mainly found in non-intermyocyte areas (1.62 ± 0.38 cm3 in AF+HT vs 0.96 ± 0.3 cm3 in AF; P < .05). Left and right atrial effective refractory periods, action potential durations, endo- and epicardial conduction velocities, and measures of AF complexity were comparable between the 2 groups. A 3-dimensional computational model confirmed an increase in AF stability observed in the in vivo experiments associated with increased atrial size. CONCLUSION In this model of secondary HT, higher AF stability after 2 weeks of RAP is mainly driven by atrial dilatation.
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Affiliation(s)
- Martin Manninger
- Division of Cardiology, Department of Medicine, Medical University of Graz, Graz, Austria.
| | - David Zweiker
- Division of Cardiology, Department of Medicine, Medical University of Graz, Graz, Austria
| | - Arne van Hunnik
- Department of Physiology, Cardiovascular Research Institute Maastricht, University of Maastricht, Maastricht, The Netherlands
| | - Alessio Alogna
- Department of Cardiology, Charité University Medicine, Campus Virchow-Klinikum, Berlin, Germany; Berlin Institute of Health (BIH), Berlin, Germany
| | - Anton J Prassl
- Institute of Biophysics, Medical University of Graz, Graz, Austria
| | - Julia Schipke
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
| | - Stef Zeemering
- Department of Physiology, Cardiovascular Research Institute Maastricht, University of Maastricht, Maastricht, The Netherlands
| | - Birgit Zirngast
- Department of Cardiothoracic Surgery, Medical University of Graz, Graz, Austria
| | - Patrick Schönleitner
- Department of Physiology, Cardiovascular Research Institute Maastricht, University of Maastricht, Maastricht, The Netherlands
| | - Michael Schwarzl
- Department of General and Interventional Cardiology, University Heart Center Hamburg-Eppendorf, Hamburg, Germany; DZHK (German Centre for Cardiovascular Research), Partner site Hamburg/Kiel/Lübeck, Berlin, Germany
| | - Viktoria Herbst
- Division of Cardiology, Department of Medicine, Medical University of Graz, Graz, Austria
| | - Eva Thon-Gutschi
- Division of Cardiology, Department of Medicine, Medical University of Graz, Graz, Austria
| | - Stefan Huber
- Department of Cardiothoracic Surgery, Medical University of Graz, Graz, Austria
| | - Ursula Rohrer
- Division of Cardiology, Department of Medicine, Medical University of Graz, Graz, Austria
| | - Jakob Ebner
- Division of Cardiology, Department of Medicine, Medical University of Graz, Graz, Austria
| | - Helmut Brussee
- Division of Cardiology, Department of Medicine, Medical University of Graz, Graz, Austria
| | - Burkert M Pieske
- Department of Physiology, Cardiovascular Research Institute Maastricht, University of Maastricht, Maastricht, The Netherlands
| | - Frank R Heinzel
- Department of Physiology, Cardiovascular Research Institute Maastricht, University of Maastricht, Maastricht, The Netherlands
| | - Sander Verheule
- Department of Physiology, Cardiovascular Research Institute Maastricht, University of Maastricht, Maastricht, The Netherlands
| | - Gudrun Antoons
- Department of Physiology, Cardiovascular Research Institute Maastricht, University of Maastricht, Maastricht, The Netherlands
| | - Andreas Lueger
- Division of Cardiology, Department of Medicine, Medical University of Graz, Graz, Austria
| | - Christian Mühlfeld
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
| | - Gernot Plank
- Institute of Biophysics, Medical University of Graz, Graz, Austria
| | - Ulrich Schotten
- Department of Physiology, Cardiovascular Research Institute Maastricht, University of Maastricht, Maastricht, The Netherlands
| | - Heiner Post
- Department of Cardiology, Charité University Medicine, Campus Virchow-Klinikum, Berlin, Germany; Department of Cardiology, Contilia Heart and Vessel Centre, St. Marien-Hospital Mülheim, Mülheim, Germany
| | - Daniel Scherr
- Division of Cardiology, Department of Medicine, Medical University of Graz, Graz, Austria; Department of Cardiology, Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, Maastricht, The Netherlands
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27
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den Uijl DW, Cabanelas N, Benito EM, Figueras R, Alarcón F, Borràs R, Prat S, Guasch E, Perea R, Sitges M, Brugada J, Berruezo A, Mont L. Impact of left atrial volume, sphericity, and fibrosis on the outcome of catheter ablation for atrial fibrillation. J Cardiovasc Electrophysiol 2018. [PMID: 29528532 DOI: 10.1111/jce.13482] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
INTRODUCTION To investigate the relation between left atrial (LA) volume, sphericity, and fibrotic content derived from contrast-enhanced cardiac magnetic resonance imaging (CE-CMR) and their impact on the outcome of catheter ablation for atrial fibrillation (AF). METHODS AND RESULTS In 83 patients undergoing catheter ablation for AF, CE-CMR was used to assess LA volume, sphericity, and fibrosis. There was a significant correlation between LA volume and sphericity (R = 0.535, P < 0.001) and between LA volume and fibrosis (R = 0.241, P = 0.029). Multivariate analyses demonstrated that LA volume was the strongest independent predictor of AF recurrence after catheter ablation (1.019, P = 0.018). CONCLUSION LA volume, sphericity, and fibrosis were closely related; however, LA volume was the strongest predictor of AF recurrence after catheter ablation.
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Affiliation(s)
- Dennis W den Uijl
- Institut Clínic Cardiovascular, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Nuno Cabanelas
- Institut Clínic Cardiovascular, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Eva M Benito
- Institut Clínic Cardiovascular, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Rosa Figueras
- Institut Clínic Cardiovascular, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Francisco Alarcón
- Institut Clínic Cardiovascular, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Roger Borràs
- Institut Clínic Cardiovascular, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Susanna Prat
- Institut Clínic Cardiovascular, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Eduard Guasch
- Institut Clínic Cardiovascular, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.,CIBERCV, Instituto de Salud Carlos III, Madrid, Spain
| | - Rosario Perea
- Institut Clínic Cardiovascular, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.,CIBERCV, Instituto de Salud Carlos III, Madrid, Spain
| | - Marta Sitges
- Institut Clínic Cardiovascular, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.,CIBERCV, Instituto de Salud Carlos III, Madrid, Spain
| | - Josep Brugada
- Institut Clínic Cardiovascular, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.,CIBERCV, Instituto de Salud Carlos III, Madrid, Spain
| | - Antonio Berruezo
- Institut Clínic Cardiovascular, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.,CIBERCV, Instituto de Salud Carlos III, Madrid, Spain
| | - Lluís Mont
- Institut Clínic Cardiovascular, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.,CIBERCV, Instituto de Salud Carlos III, Madrid, Spain
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Affiliation(s)
- Jordi Heijman
- From the Department of Cardiology, Cardiovascular Research Institute Maastricht, Faculty of Health, Medicine, and Life Sciences, Maastricht University, The Netherlands (J.H.); Department of Medicine, Montreal Heart Institute and Université de Montréal, Canada (J.-B.G., S.N.); University Hospital of Saint-Étienne, University Jean Monnet, Saint-Étienne, France (J.-B.G.); Institute of Pharmacology, West German Heart and Vascular Center, Faculty of Medicine, University Duisburg-Essen (D.D., S.N.); and
| | - Jean-Baptiste Guichard
- From the Department of Cardiology, Cardiovascular Research Institute Maastricht, Faculty of Health, Medicine, and Life Sciences, Maastricht University, The Netherlands (J.H.); Department of Medicine, Montreal Heart Institute and Université de Montréal, Canada (J.-B.G., S.N.); University Hospital of Saint-Étienne, University Jean Monnet, Saint-Étienne, France (J.-B.G.); Institute of Pharmacology, West German Heart and Vascular Center, Faculty of Medicine, University Duisburg-Essen (D.D., S.N.); and
| | - Dobromir Dobrev
- From the Department of Cardiology, Cardiovascular Research Institute Maastricht, Faculty of Health, Medicine, and Life Sciences, Maastricht University, The Netherlands (J.H.); Department of Medicine, Montreal Heart Institute and Université de Montréal, Canada (J.-B.G., S.N.); University Hospital of Saint-Étienne, University Jean Monnet, Saint-Étienne, France (J.-B.G.); Institute of Pharmacology, West German Heart and Vascular Center, Faculty of Medicine, University Duisburg-Essen (D.D., S.N.); and
| | - Stanley Nattel
- From the Department of Cardiology, Cardiovascular Research Institute Maastricht, Faculty of Health, Medicine, and Life Sciences, Maastricht University, The Netherlands (J.H.); Department of Medicine, Montreal Heart Institute and Université de Montréal, Canada (J.-B.G., S.N.); University Hospital of Saint-Étienne, University Jean Monnet, Saint-Étienne, France (J.-B.G.); Institute of Pharmacology, West German Heart and Vascular Center, Faculty of Medicine, University Duisburg-Essen (D.D., S.N.); and
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Guasch E, Mont L, Sitges M. Mechanisms of atrial fibrillation in athletes: what we know and what we do not know. Neth Heart J 2018; 26:133-145. [PMID: 29411287 PMCID: PMC5818379 DOI: 10.1007/s12471-018-1080-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Exercise is an emerging cause of atrial fibrillation (AF) in young individuals without coexisting cardiovascular risk factors. The causes of exercise-induced atrial fibrillation remain largely unknown, and conclusions are jeopardised by apparently conflicting data. Some components of the athlete's heart are known to be arrhythmogenic in other settings. Bradycardia, atrial dilatation and, possibly, atrial premature beats are therefore biologically plausible contributors to exercise-induced AF. Challenging findings in an animal model suggest that exercise might also prompt the development of atrial fibrosis, possibly due to cumulative minor structural damage after each exercise bout. However, there is very limited, indirect data supporting this hypothesis in athletes. Age, sex, the presence of comorbidities and cardiovascular risk factors, and genetic individual variability might serve to flag those athletes who are at the higher risk of exercise-induced AF. In this review, we will critically address current knowledge on the mechanisms of exercise-induced AF.
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Affiliation(s)
- E Guasch
- Institut Clinic Cardiovascular, Hospital Clínic de Barcelona; IDIBAPS; Universitat de Barcelona; CIBERCV., 08036, Barcelona, Catalonia, Spain.
| | - L Mont
- Institut Clinic Cardiovascular, Hospital Clínic de Barcelona; IDIBAPS; Universitat de Barcelona; CIBERCV., 08036, Barcelona, Catalonia, Spain
| | - M Sitges
- Institut Clinic Cardiovascular, Hospital Clínic de Barcelona; IDIBAPS; Universitat de Barcelona; CIBERCV., 08036, Barcelona, Catalonia, Spain
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30
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Ishii Y, Sakamoto SI, Miyagi Y, Kawase Y, Otsuka T, Nitta T. Risk Factors of Recurrence of Atrial Fibrillation (AF) After AF Surgery in Patients With AF and Mitral Valve Disease. Semin Thorac Cardiovasc Surg 2018; 30:271-278. [DOI: 10.1053/j.semtcvs.2018.01.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/29/2018] [Indexed: 11/11/2022]
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Jacquemet V. A statistical model of false negative and false positive detection of phase singularities. CHAOS (WOODBURY, N.Y.) 2017; 27:103124. [PMID: 29092458 DOI: 10.1063/1.4999939] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The complexity of cardiac fibrillation dynamics can be assessed by analyzing the distribution of phase singularities (PSs) observed using mapping systems. Interelectrode distance, however, limits the accuracy of PS detection. To investigate in a theoretical framework the PS false negative and false positive rates in relation to the characteristics of the mapping system and fibrillation dynamics, we propose a statistical model of phase maps with controllable number and locations of PSs. In this model, phase maps are generated from randomly distributed PSs with physiologically-plausible directions of rotation. Noise and distortion of the phase are added. PSs are detected using topological charge contour integrals on regular grids of varying resolutions. Over 100 × 106 realizations of the random field process are used to estimate average false negative and false positive rates using a Monte-Carlo approach. The false detection rates are shown to depend on the average distance between neighboring PSs expressed in units of interelectrode distance, following approximately a power law with exponents in the range of 1.14 to 2 for false negatives and around 2.8 for false positives. In the presence of noise or distortion of phase, false detection rates at high resolution tend to a non-zero noise-dependent lower bound. This model provides an easy-to-implement tool for benchmarking PS detection algorithms over a broad range of configurations with multiple PSs.
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Affiliation(s)
- Vincent Jacquemet
- Département de Pharmacologie et Physiologie, Institut de Génie Biomédical, Université de Montréal, Montréal, Québec H4J 1C5, Canada
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32
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Hummel JP, Baher A, Buck B, Fanarjian M, Webber CL, Akar JG. A method for quantifying recurrent patterns of local wavefront direction during atrial fibrillation. Comput Biol Med 2017; 89:497-504. [PMID: 28889077 DOI: 10.1016/j.compbiomed.2017.08.027] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Revised: 08/24/2017] [Accepted: 08/25/2017] [Indexed: 10/18/2022]
Abstract
INTRODUCTION Spiral wave reentry is a potential mechanism of atrial fibrillation (AF), but is difficult to differentiate clinically from multiple wavelet breakup using standard bipolar recordings. We developed a new methodology using bipolar recordings to estimate the direction of local activation wavefronts during AF by calculating the electrogram conformation (Egm-C). We subsequently used recurrence quantification analysis (RQA) of Egm-C to differentiate regions of spiral wave reentry from wavelet breakup. METHODS A 2D computer simulation was created with regions containing a stable spiral wave and also regions of wavebreak. A grid of 40 × 40 unipolar electrodes was superimposed. At each site, the actual wavefront direction (WD) was determined by comparing relative activation timings of the local intracellular recordings, and the estimated wavefront direction (Egm-C) was determined from the morphology of the local bipolar electrogram. RQA of Egm-C was compared to RQA of actual WD in order to differentiate AF mechanisms. RESULTS RQA of actual WD and Egm-C both distinguished regions of spiral wave reentry from wavelet breakup with high correlation between the two methods (recurrence rate, r = 0.96; determinism, r = 0.61; line max, r = 0.95; entropy, r = 0.84; p < 0.001 for all). In areas of stable spiral wave reentry, the recurrence plots of both Egm-C and actual WD demonstrated stable, periodic dynamics, while regions of wavelet breakup demonstrated chaotic behavior largely devoid of repetitive activation patterns. CONCLUSION Calculation of Egm-C allows RQA to be performed on bipolar electrograms during AF and differentiates regions of spiral wave reentry from multiple wavelet breakup.
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Affiliation(s)
- James P Hummel
- Division of Cardiology, University of North Carolina, Chapel Hill, NC, USA.
| | - Alex Baher
- The Section of Cardiovascular Medicine, Department of Medicine, Yale University School of Medicine, New Haven, CT, USA
| | - Ben Buck
- Division of Cardiology, University of North Carolina, Chapel Hill, NC, USA
| | - Manuel Fanarjian
- Division of Cardiology, University of North Carolina, Chapel Hill, NC, USA
| | - Charles L Webber
- Department of Cell and Molecular Physiology, Loyola University Chicago - Health Sciences Division, Maywood, IL, USA
| | - Joseph G Akar
- The Section of Cardiovascular Medicine, Department of Medicine, Yale University School of Medicine, New Haven, CT, USA
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Meng T, Cheng G, Wei Y, Ma S, Jiang Y, Wu J, Zhou X, Sun C. Exposure to a chronic high-fat diet promotes atrial structure and gap junction remodeling in rats. Int J Mol Med 2017; 40:217-225. [DOI: 10.3892/ijmm.2017.2982] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2016] [Accepted: 05/05/2017] [Indexed: 11/05/2022] Open
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Nattel S, Xiong F, Aguilar M. Demystifying rotors and their place in clinical translation of atrial fibrillation mechanisms. Nat Rev Cardiol 2017; 14:509-520. [PMID: 28383023 DOI: 10.1038/nrcardio.2017.37] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Treatment of atrial fibrillation (AF), the most common arrhythmia in clinical practice, remains challenging. Improved understanding of underlying mechanisms is needed to improve therapy. Functional re-entry is central to AF maintenance. The first detailed, quantitative theory of functional re-entry, the 'leading circle' model, was developed 40 years ago. Subsequently, an alternative paradigm based on 'spiral waves' has evolved. Spiral-wave generators, or 'rotors', have been identified using advanced mapping methods in experimental and clinical AF. A central tool in the analysis of spiral-wave rotors is the phase transformation, allowing for easier visualization of rotors and tracking of 'phase singularity' points at the rotor tip. In contrast to leading circle theory, which is expressed in terms familiar to (and easily understood by) cardiologists, the ideas needed to understand rotors are much more theoretical and harder for clinicians to apply. In this Review, we summarize the basic notions of phase mapping and spiral-wave rotors, and the ways in which rotor sources might be involved in AF maintenance. We discuss competing observations about the role of spatially confined rotors, short-lived rotors clustered at the edge of fibrotic zones, endocardial-epicardial interactive breeder properties and transmural re-entry, as well as studies underway to resolve them. We conclude with consideration of the clinical relevance of the issues discussed and their potential implications for the management of patients with AF.
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Affiliation(s)
- Stanley Nattel
- Department of Medicine and Research Center, Montreal Heart Institute and Université de Montréal, 5000 Belanger Street East, Montreal, Quebec H1T 1C8, Canada.,Department of Pharmacology and Therapeutics, McGill University, 3655 Promenade Sir William Osler, Montreal, Quebec H3G 1Y6, Canada.,Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Hufeland Strasse 55, 45122 Essen, Germany
| | - Feng Xiong
- Department of Medicine and Research Center, Montreal Heart Institute and Université de Montréal, 5000 Belanger Street East, Montreal, Quebec H1T 1C8, Canada
| | - Martin Aguilar
- Department of Medicine and Research Center, Montreal Heart Institute and Université de Montréal, 5000 Belanger Street East, Montreal, Quebec H1T 1C8, Canada
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36
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Kim TH, Park J, Uhm JS, Kim JY, Joung B, Lee MH, Pak HN. Challenging Achievement of Bidirectional Block After Linear Ablation Affects the Rhythm Outcome in Patients With Persistent Atrial Fibrillation. J Am Heart Assoc 2016; 5:JAHA.116.003894. [PMID: 27792644 PMCID: PMC5121491 DOI: 10.1161/jaha.116.003894] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Background It is not clear whether bidirectional block (BDB) of linear ablations reduces atrial fibrillation (AF) recurrence after radiofrequency catheter ablation. We hypothesized that BDB of linear ablation has prognostic significance after radiofrequency catheter ablation for persistent AF. Methods and Results Among 1793 consecutive patients in the Yonsei AF ablation cohort, this observational cohort study included 398 patients with persistent AF (75.6% male; age, 59.8±10.3 years) who underwent catheter ablation with a consistent ablation protocol of the Dallas lesion set: circumferential pulmonary vein isolation; cavotricuspid isthmus ablation (CTI); roof line (RL); posterior‐inferior line (PIL); and anterior line (AL). BDB rates of de novo ablation lines were 100% in circumferential pulmonary vein isolation, 100% in CTI, 84.7% in RL, 44.7% in PIL, and 63.6% in AL. During 29.0±18.4 months of follow‐up, 31.7% (126/398) of the patients showed clinical recurrence. Left atrial posterior wall (LAPW) isolation (BDBs of RL and PIL) was independently associated with lower clinical AF/atrial tachycardia recurrence (hazard ratio, 0.68; 95% CI, 0.47–0.98; P=0.041; log‐rank, P=0.017), whereas BDBs of RL or AL were not (log‐rank, P=0.178 for RL; P=0.764 for AL). Among 52 patients who underwent repeat procedures (23.0±16.1 months after de novo procedure), the BDB maintenance rates for CTI, RL, PIL, and AL were 94.2% (49 of 52), 63.5% (33 of 47), 62.1% (18 of 29), and 61.8% (21 of 34), respectively. Conclusions Although PIL crosses the esophageal contact area, LAPW isolation is important for better clinical outcome in catheter ablation with a linear ablation strategy for patients with persistent AF.
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Affiliation(s)
| | | | - Jae-Sun Uhm
- Yonsei University Health System, Seoul, Korea
| | | | | | | | - Hui-Nam Pak
- Yonsei University Health System, Seoul, Korea
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37
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Takemoto Y, Ramirez RJ, Yokokawa M, Kaur K, Ponce-Balbuena D, Sinno MC, Willis BC, Ghanbari H, Ennis SR, Guerrero-Serna G, Henzi BC, Latchamsetty R, Ramos-Mondragon R, Musa H, Martins RP, Pandit SV, Noujaim SF, Crawford T, Jongnarangsin K, Pelosi F, Bogun F, Chugh A, Berenfeld O, Morady F, Oral H, Jalife J. Galectin-3 Regulates Atrial Fibrillation Remodeling and Predicts Catheter Ablation Outcomes. JACC Basic Transl Sci 2016; 1:143-154. [PMID: 27525318 PMCID: PMC4979747 DOI: 10.1016/j.jacbts.2016.03.003] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Atrial fibrillation (AF) usually starts as paroxysmal but can evolve relentlessly to the persistent and permanent forms. However, the mechanisms governing such a transition are unknown. The authors show that intracardiac serum levels of galectin (Gal)-3 are greater in patients with persistent than paroxysmal AF and that Gal-3 independently predicts atrial tachyarrhythmia recurrences after a single ablation procedure. Using a sheep model of persistent AF the authors further demonstrate that upstream therapy targeting Gal-3 diminishes both electrical remodeling and fibrosis by impairing transforming growth factor beta–mediated signaling and reducing myofibroblast activation. Accordingly, Gal-3 inhibition therapy increases the probability of AF termination and reduces the overall burden of AF. Therefore the authors postulate that Gal-3 inhibition is a potential new upstream therapy to prevent AF progression. Intracardiac serum galectin (Gal)-3 levels are shown to be greater in patients with persistent than paroxysmal atrial fibrillation (AF), and the Gal-3 level was an independent predictor of AF recurrences after a single ablation procedure. In a sheep model, the Gal-3 inhibitor GM-CT-01 (GMCT) reduced atrial fibroblast proliferation in vitro. GMCT mitigated atrial dilation, myocyte hypertrophy, fibrosis, and the expected increase in DF during transition to persistent AF. GMCT-treated sheep hearts had longer action potential durations, and fewer rotors and wavebreaks during AF than control. GMCT increased the number of spontaneous AF terminations and reduced overall AF burden.
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Affiliation(s)
- Yoshio Takemoto
- Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI
| | - Rafael J Ramirez
- Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI
| | - Miki Yokokawa
- Division of Cardiovascular Medicine, Cardiac Arrhythmia Service, University of Michigan, Ann Arbor, MI
| | - Kuljeet Kaur
- Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI
| | - Daniela Ponce-Balbuena
- Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI
| | - Mohamad C Sinno
- Division of Cardiovascular Medicine, Cardiac Arrhythmia Service, University of Michigan, Ann Arbor, MI
| | - B Cicero Willis
- Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI
| | - Hamid Ghanbari
- Division of Cardiovascular Medicine, Cardiac Arrhythmia Service, University of Michigan, Ann Arbor, MI
| | - Steven R Ennis
- Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI
| | - Guadalupe Guerrero-Serna
- Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI
| | - Bettina C Henzi
- Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI
| | - Rakesh Latchamsetty
- Division of Cardiovascular Medicine, Cardiac Arrhythmia Service, University of Michigan, Ann Arbor, MI
| | - Roberto Ramos-Mondragon
- Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI
| | - Hassan Musa
- Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI
| | - Raphael P Martins
- Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI
| | - Sandeep V Pandit
- Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI
| | - Sami F Noujaim
- Molecular Cardiology Research Institute, Tufts Medical Center, Boston, MA
| | - Thomas Crawford
- Division of Cardiovascular Medicine, Cardiac Arrhythmia Service, University of Michigan, Ann Arbor, MI
| | - Krit Jongnarangsin
- Division of Cardiovascular Medicine, Cardiac Arrhythmia Service, University of Michigan, Ann Arbor, MI
| | - Frank Pelosi
- Division of Cardiovascular Medicine, Cardiac Arrhythmia Service, University of Michigan, Ann Arbor, MI
| | - Frank Bogun
- Division of Cardiovascular Medicine, Cardiac Arrhythmia Service, University of Michigan, Ann Arbor, MI
| | - Aman Chugh
- Division of Cardiovascular Medicine, Cardiac Arrhythmia Service, University of Michigan, Ann Arbor, MI
| | - Omer Berenfeld
- Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI
| | - Fred Morady
- Division of Cardiovascular Medicine, Cardiac Arrhythmia Service, University of Michigan, Ann Arbor, MI
| | - Hakan Oral
- Division of Cardiovascular Medicine, Cardiac Arrhythmia Service, University of Michigan, Ann Arbor, MI
| | - José Jalife
- Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI
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Pellman J, Sheikh F. Atrial fibrillation: mechanisms, therapeutics, and future directions. Compr Physiol 2016; 5:649-65. [PMID: 25880508 DOI: 10.1002/cphy.c140047] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia, affecting 1% to 2% of the general population. It is characterized by rapid and disorganized atrial activation leading to impaired atrial function, which can be diagnosed on an EKG by lack of a P-wave and irregular QRS complexes. AF is associated with increased morbidity and mortality and is a risk factor for embolic stroke and worsening heart failure. Current research on AF support and explore the hypothesis that initiation and maintenance of AF require pathophysiological remodeling of the atria, either specifically as in lone AF or secondary to other heart disease as in heart failure-associated AF. Remodeling in AF can be grouped into three categories that include: (i) electrical remodeling, which includes modulation of L-type Ca(2+) current, various K(+) currents and gap junction function; (ii) structural remodeling, which includes changes in tissues properties, size, and ultrastructure; and (iii) autonomic remodeling, including altered sympathovagal activity and hyperinnervation. Electrical, structural, and autonomic remodeling all contribute to creating an AF-prone substrate which is able to produce AF-associated electrical phenomena including a rapidly firing focus, complex multiple reentrant circuit or rotors. Although various remodeling events occur in AF, current AF therapies focus on ventricular rate and rhythm control strategies using pharmacotherapy and surgical interventions. Recent progress in the field has started to focus on the underlying substrate that drives and maintains AF (termed upstream therapies); however, much work is needed in this area. Here, we review current knowledge of AF mechanisms, therapies, and new areas of investigation.
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Affiliation(s)
- Jason Pellman
- Department of Medicine, University of California, San Diego, La Jolla, California, USA
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39
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Yu TM, Chuang YW, Yu MC, Huang ST, Chou CY, Lin CL, Chiu CC, Kao CH. New-onset Atrial Fibrillation is Associated With Polycystic Kidney Disease: A Nationwide Population-based Cohort Study. Medicine (Baltimore) 2016; 95:e2623. [PMID: 26825919 PMCID: PMC5291589 DOI: 10.1097/md.0000000000002623] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Cardiovascular complications remain the major problems contributing to morbidity and mortality in patients with polycystic kidney disease (PKD). Therefore, the authors hypothesized that atrial fibrillation (AF) is closely associated with PKD. The authors conducted a nationwide population-based cohort study to investigate the risk of AF in patients with PKD. Using data from inpatient claims, the authors enrolled 7203 patients aged over 20 years who were diagnosed with PKD from 1998 to 2010 with no history of AF as the PKD cohort. They randomly selected 28,739 people without PKD as controls and frequency matched them with patients with PKD according to their age, sex, and baseline comorbidity. In total, 247 PKD patients were diagnosed with AF, representing an incidence of 7.08 per 1000 person-years, whereas 807 cases of AF occurred in the comparison cohort, yielding an incidence of 4.98 per 1000 person-y, with an adjusted HR (aHR) of 1.31 (95% CI = 1.14-1.51). The risk of AF increased from an aHR of 1.59 (95% CI = 1.15-2.21) to 3.64 (95% CI = 1.93-6.85) when the number of risk factors increased from 1 to more than 5 in comparison with patients without risk factors. A remarkably high incidence rate and risk was observed in patients with PKD when multiple risk factors were combined. A high index of suspicion should be maintained when examining PKD patients with irregular betas. Early prophylactic therapy is warranted in these patients.
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Affiliation(s)
- Tung-Min Yu
- From the Graduate Institute of Clinical Medical Science and School of Medicine, College of Medicine, China Medical University (T-MY, C-HK); Division of Nephrology, Taichung Veterans General Hospital, Taichung (T-MY, Y-WC); Department of Pediatric Nephrology, Chang Gung Children's Hospital at Linkou, Chang Gung University College of Medicine, Taoyuan (M-CY); Management Office for Health Data, China Medical University Hospital, Taichung (C-LL); Neurology and Medical Intensive Care Unit, Changhua Christian Hospital, Changhua (C-CC); College of Medicine, China Medical University (C-LL); and Department of Nuclear Medicine and PET Center, China Medical University Hospital, Taichung, Taiwan (C-HK)
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Rappel WJ, Zaman JAB, Narayan SM. Mechanisms for the Termination of Atrial Fibrillation by Localized Ablation: Computational and Clinical Studies. Circ Arrhythm Electrophysiol 2015; 8:1325-33. [PMID: 26359479 PMCID: PMC4764078 DOI: 10.1161/circep.115.002956] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 08/20/2015] [Indexed: 12/26/2022]
Abstract
BACKGROUND Human atrial fibrillation (AF) can terminate after ablating localized regions, which supports the existence of localized rotors (spiral waves) or focal drivers. However, it is unclear why ablation near a spiral wave tip would terminate AF and not anchor reentry. We addressed this question by analyzing competing mechanisms for AF termination in numeric simulations, referenced to clinical observations. METHODS AND RESULTS Spiral wave reentry was simulated in monodomain 2-dimensional myocyte sheets using clinically realistic rate-dependent values for repolarization and conduction. Heterogeneous models were created by introduction of parameterized variations in tissue excitability. Ablation lesions were applied as nonconducting circular regions. Models confirmed that localized ablation may anchor spiral wave reentry, producing organized tachycardias. Several mechanisms referenced to clinical observations explained termination of AF to sinus rhythm. First, lesions may create an excitable gap vulnerable to invasion by fibrillatory waves. Second, ablation of rotors in regions of low-excitability (from remodeling) produced re-entry in more excitable tissue allowing collision of wavefront and back. Conversely, ablation of rotors in high-excitability regions migrated spiral waves to less excitable tissue, where they detached to collide with nonconducting boundaries. Third, ablation may connect rotors to nonconducting anatomic orifices. Fourth, reentry through slow-conducting channels may terminate if ablation closes these channels. CONCLUSIONS Limited ablation can terminate AF by several mechanisms. These data shed light on how clinical AF may be sustained in patients' atria, emphasizing heterogeneities in tissue excitability, slow-conducting channels, and obstacles that are increasingly detectable in patients and should be the focus of future translational studies.
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Affiliation(s)
- Wouter-Jan Rappel
- From the Department of Physics, University of California, San Diego (W.-J.R.); Department of Cardiology, Imperial College, University of London, London, United Kingdom (J.A.B.Z.); and Department of Medicine, Stanford University, Palo Alto, CA (J.A.B.Z., S.M.N.).
| | - Junaid A B Zaman
- From the Department of Physics, University of California, San Diego (W.-J.R.); Department of Cardiology, Imperial College, University of London, London, United Kingdom (J.A.B.Z.); and Department of Medicine, Stanford University, Palo Alto, CA (J.A.B.Z., S.M.N.)
| | - Sanjiv M Narayan
- From the Department of Physics, University of California, San Diego (W.-J.R.); Department of Cardiology, Imperial College, University of London, London, United Kingdom (J.A.B.Z.); and Department of Medicine, Stanford University, Palo Alto, CA (J.A.B.Z., S.M.N.).
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Matene E, Vinet A, Jacquemet V. Dynamics of atrial arrhythmias modulated by time-dependent acetylcholine concentration: a simulation study. Europace 2015; 16 Suppl 4:iv11-iv20. [PMID: 25362160 DOI: 10.1093/europace/euu255] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
AIM The autonomic nervous system modulates atrial activity, notably through acetylcholine (ACh) release. This time-dependent action may alter the dynamics of atrial arrhythmia. Our aim is to investigate in a computer model the changes induced by ACh release and degradation on the dynamical regime of a reentry. METHODS AND RESULTS A functional reentry was simulated in a 10 × 5 cm(2) two-dimensional tissue with canine atrial membrane kinetics including an ACh-dependent K(+) current. The local ACh concentration was altered over time in a circular region following a predefined spatiotemporal profile (ACh release and degradation) characterized by its maximum ACh level, time constant of release/degradation, and diameter of the region. Phase singularities were tracked to monitor the complexity of the dynamics. Four scenarios were identified: (i) the original reentry remained stable; (ii) repolarization gradients induced by ACh release caused wavebreaks, resulting in a transient complex dynamics that spontaneously converted to a single stable reentry; (iii) the reentry self-terminated through wavebreaks and wavefront interactions; (4) wavebreaks led to a complex dynamics that converted to two or three reentries that remained stable after ACh degradation. Higher ACh level, short ACh release time constant, larger heterogeneous region, and short distance between the heterogeneous region and the spiral tip were associated with higher occurrence of ACh-induced wavebreaks. CONCLUSION Variation of ACh concentration over time may modulate the complexity of atrial arrhythmias.
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Affiliation(s)
- Elhacene Matene
- Centre de Recherche, Hôpital du Sacré-Coeur de Montréal, 5400, boul. Gouin Ouest, Montreal, QC, Canada H4J 1C5 Département de Physiologie Moléculaire et Intégrative, Institut de Génie Biomédical, Université de Montréal, Montreal, QC, Canada H3T 1J4
| | - Alain Vinet
- Centre de Recherche, Hôpital du Sacré-Coeur de Montréal, 5400, boul. Gouin Ouest, Montreal, QC, Canada H4J 1C5 Département de Physiologie Moléculaire et Intégrative, Institut de Génie Biomédical, Université de Montréal, Montreal, QC, Canada H3T 1J4
| | - Vincent Jacquemet
- Centre de Recherche, Hôpital du Sacré-Coeur de Montréal, 5400, boul. Gouin Ouest, Montreal, QC, Canada H4J 1C5 Département de Physiologie Moléculaire et Intégrative, Institut de Génie Biomédical, Université de Montréal, Montreal, QC, Canada H3T 1J4
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Ren M, Li X, Hao L, Zhong J. Role of tumor necrosis factor alpha in the pathogenesis of atrial fibrillation: A novel potential therapeutic target? Ann Med 2015; 47:316-24. [PMID: 25982799 DOI: 10.3109/07853890.2015.1042030] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Atrial fibrillation (AF) is the most common sustained arrhythmia in clinical practice and a major cause of morbidity and mortality. Although the fundamental mechanisms underlying AF remain incompletely understood, atrial remodeling, including structural, electrical, contractile, and autonomic remodeling, has been demonstrated to contribute to the substrate for AF maintenance. Accumulating evidence shows that tumor necrosis factor alpha (TNF-α) plays exceedingly important roles in atrial remodeling. This article reviews recent advances in the roles of TNF-α in the pathogenesis of AF, elucidates the related mechanisms, and exploits its potential usefulness as a novel therapeutic target.
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Affiliation(s)
- Manyi Ren
- Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health, Department of Cardiology, Qilu Hospital of Shandong University , China
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Kim JS, Shin SY, Na JO, Choi CU, Kim SH, Kim JW, Kim EJ, Rha SW, Park CG, Seo HS, Oh DJ, Hwang C, Lim HE. Does isolation of the left atrial posterior wall improve clinical outcomes after radiofrequency catheter ablation for persistent atrial fibrillation? Int J Cardiol 2015; 181:277-83. [DOI: 10.1016/j.ijcard.2014.12.035] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Revised: 11/01/2014] [Accepted: 12/10/2014] [Indexed: 10/24/2022]
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Abstract
Atrial fibrillation (AF), the most common sustained arrhythmia in clinical practice, is an important contributor to cardiac morbidity and mortality. Pharmacological approaches currently available to treat patients with AF lack sufficient efficacy and are associated with potential adverse effects. Even though ablation is generally more effective than pharmacotherapy, this invasive procedure has considerable potential complications and is limited by long-term recurrences. Novel therapies based on the underlying molecular mechanisms of AF can provide useful alternatives to current treatments. MicroRNAs (miRNAs), endogenous short RNA sequences that regulate gene expression, have been implicated in the control of AF, providing novel insights into the molecular basis of the pathogenesis of AF and suggesting miRNA targeting as a potential approach for the management of this common arrhythmia. In this Review, we provide a comprehensive analysis of the current experimental evidence supporting miRNAs as important factors in AF and discuss their therapeutic implications. We first provide background information on the pathophysiology of AF and the biological determinants of miRNA synthesis and action, followed by experimental evidence for miRNA-mediated regulation of AF, and finally provide a comprehensive overview of miRNAs as potential novel therapeutic targets for AF.
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45
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Nishida K, Datino T, Macle L, Nattel S. Atrial Fibrillation Ablation. J Am Coll Cardiol 2014; 64:823-31. [DOI: 10.1016/j.jacc.2014.06.1172] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Revised: 06/26/2014] [Accepted: 06/27/2014] [Indexed: 10/24/2022]
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Trayanova NA. Mathematical approaches to understanding and imaging atrial fibrillation: significance for mechanisms and management. Circ Res 2014; 114:1516-31. [PMID: 24763468 DOI: 10.1161/circresaha.114.302240] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Atrial fibrillation (AF) is the most common sustained arrhythmia in humans. The mechanisms that govern AF initiation and persistence are highly complex, of dynamic nature, and involve interactions across multiple temporal and spatial scales in the atria. This article aims to review the mathematical modeling and computer simulation approaches to understanding AF mechanisms and aiding in its management. Various atrial modeling approaches are presented, with descriptions of the methodological basis and advancements in both lower-dimensional and realistic geometry models. A review of the most significant mechanistic insights made by atrial simulations is provided. The article showcases the contributions that atrial modeling and simulation have made not only to our understanding of the pathophysiology of atrial arrhythmias, but also to the development of AF management approaches. A summary of the future developments envisioned for the field of atrial simulation and modeling is also presented. The review contends that computational models of the atria assembled with data from clinical imaging modalities that incorporate electrophysiological and structural remodeling could become a first line of screening for new AF therapies and approaches, new diagnostic developments, and new methods for arrhythmia prevention.
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Affiliation(s)
- Natalia A Trayanova
- From the Department of Biomedical Engineering and Institute for Computational Medicine, Johns Hopkins University, Baltimore, MD
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47
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Andrade J, Khairy P, Dobrev D, Nattel S. The clinical profile and pathophysiology of atrial fibrillation: relationships among clinical features, epidemiology, and mechanisms. Circ Res 2014; 114:1453-68. [PMID: 24763464 DOI: 10.1161/circresaha.114.303211] [Citation(s) in RCA: 799] [Impact Index Per Article: 79.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Atrial fibrillation (AF) is the most common arrhythmia (estimated lifetime risk, 22%-26%). The aim of this article is to review the clinical epidemiological features of AF and to relate them to underlying mechanisms. Long-established risk factors for AF include aging, male sex, hypertension, valve disease, left ventricular dysfunction, obesity, and alcohol consumption. Emerging risk factors include prehypertension, increased pulse pressure, obstructive sleep apnea, high-level physical training, diastolic dysfunction, predisposing gene variants, hypertrophic cardiomyopathy, and congenital heart disease. Potential risk factors are coronary artery disease, kidney disease, systemic inflammation, pericardial fat, and tobacco use. AF has substantial population health consequences, including impaired quality of life, increased hospitalization rates, stroke occurrence, and increased medical costs. The pathophysiology of AF centers around 4 general types of disturbances that promote ectopic firing and reentrant mechanisms, and include the following: (1) ion channel dysfunction, (2) Ca(2+)-handling abnormalities, (3) structural remodeling, and (4) autonomic neural dysregulation. Aging, hypertension, valve disease, heart failure, myocardial infarction, obesity, smoking, diabetes mellitus, thyroid dysfunction, and endurance exercise training all cause structural remodeling. Heart failure and prior atrial infarction also cause Ca(2+)-handling abnormalities that lead to focal ectopic firing via delayed afterdepolarizations/triggered activity. Neural dysregulation is central to atrial arrhythmogenesis associated with endurance exercise training and occlusive coronary artery disease. Monogenic causes of AF typically promote the arrhythmia via ion channel dysfunction, but the mechanisms of the more common polygenic risk factors are still poorly understood and under intense investigation. Better recognition of the clinical epidemiology of AF, as well as an improved appreciation of the underlying mechanisms, is needed to develop improved methods for AF prevention and management.
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Affiliation(s)
- Jason Andrade
- From Department of Medicine and Research Center, Montreal Heart Institute and Université de Montréal, Montreal, Quebec, Canada (J.A., P.K., S.N.); Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada (J.A.); and Faculty of Medicine, Institute of Pharmacology, University Duisburg-Essen, Essen, Germany (D.D.)
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Nattel S, Harada M. Atrial remodeling and atrial fibrillation: recent advances and translational perspectives. J Am Coll Cardiol 2014; 63:2335-45. [PMID: 24613319 DOI: 10.1016/j.jacc.2014.02.555] [Citation(s) in RCA: 477] [Impact Index Per Article: 47.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Revised: 02/11/2014] [Accepted: 02/17/2014] [Indexed: 02/06/2023]
Abstract
Atrial fibrillation (AF) is the most common sustained arrhythmia in clinical practice. AF and its complications are responsible for important population morbidity and mortality. Presently available therapeutic approaches have limited efficacy and nontrivial potential to cause adverse effects. Thus, new mechanistic knowledge is essential for therapeutic innovation. Atrial arrhythmogenic remodeling, defined as any change in atrial structure or function that promotes atrial arrhythmias, is central to AF. Remodeling can be due to underlying cardiac conditions, systemic processes and conditions such as aging, or AF itself. Recent work has underlined the importance of remodeling in AF, provided new insights into basic mechanisms, and identified new biomarker/imaging approaches to follow remodeling processes. The importance of intracellular Ca(2+) handling abnormalities has been highlighted, both for the induction of triggered ectopic activity and for the activation of Ca(2+)-related cell signaling that mediates profibrillatory remodeling. The importance of microRNAs, which are a new class of small noncoding sequences that regulate gene expression, has emerged in both electrical and structural remodeling. Remodeling related to aging, cardiac disease, and AF itself is believed to underlie the progressive nature of the arrhythmia, which contributes to the complexities of long-term management. New tools that are being developed to quantify remodeling processes and monitor their progression include novel biomarkers, imaging modalities to quantify/localize fibrosis, and noninvasive monitoring/mapping to better characterize the burden of AF and identify arrhythmic sources. This report reviews recent advances in the understanding of the basic pathophysiology of atrial remodeling and potential therapeutic implications.
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Affiliation(s)
- Stanley Nattel
- Department of Medicine and Research Center, Montreal Heart Institute and Université de Montréal, Montreal, Quebec, Canada.
| | - Masahide Harada
- Department of Medicine and Research Center, Montreal Heart Institute and Université de Montréal, Montreal, Quebec, Canada; Department of Cardiology, Hamamatsu Medical Center, Hamamatsu, Japan
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49
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Li N, Chiang DY, Wang S, Wang Q, Sun L, Voigt N, Respress JL, Ather S, Skapura DG, Jordan VK, Horrigan FT, Schmitz W, Müller FU, Valderrabano M, Nattel S, Dobrev D, Wehrens XHT. Ryanodine receptor-mediated calcium leak drives progressive development of an atrial fibrillation substrate in a transgenic mouse model. Circulation 2014; 129:1276-1285. [PMID: 24398018 DOI: 10.1161/circulationaha.113.006611] [Citation(s) in RCA: 147] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND The progression of atrial fibrillation (AF) from paroxysmal to persistent forms remains a major clinical challenge. Abnormal sarcoplasmic reticulum (SR) Ca(2+) leak via the ryanodine receptor type 2 (RyR2) has been observed as a source of ectopic activity in various AF models. However, its potential role in progression to long-lasting spontaneous AF (sAF) has never been tested. This study was designed to test the hypothesis that enhanced RyR2-mediated Ca(2+) release underlies the development of a substrate for sAF and to elucidate the underlying mechanisms. METHODS AND RESULTS CREM-IbΔC-X transgenic (CREM) mice developed age-dependent progression from spontaneous atrial ectopy to paroxysmal and eventually long-lasting AF. The development of sAF in CREM mice was preceded by enhanced diastolic Ca(2+) release, atrial enlargement, and marked conduction abnormalities. Genetic inhibition of Ca(2+)/calmodulin-dependent protein kinase II-mediated RyR2-S2814 phosphorylation in CREM mice normalized open probability of RyR2 channels and SR Ca(2+) release, delayed the development of spontaneous atrial ectopy, fully prevented sAF, suppressed atrial dilation, and forestalled atrial conduction abnormalities. Hyperactive RyR2 channels directly stimulated the Ca(2+)-dependent hypertrophic pathway nuclear factor of activated T cell/Rcan1-4, suggesting a role for the nuclear factor of activated T cell/Rcan1-4 system in the development of a substrate for long-lasting AF in CREM mice. CONCLUSIONS RyR2-mediated SR Ca(2+) leak directly underlies the development of a substrate for sAF in CREM mice, the first demonstration of a molecular mechanism underlying AF progression and sAF substrate development in an experimental model. Our work demonstrates that the role of abnormal diastolic Ca(2+) release in AF may not be restricted to the generation of atrial ectopy but extends to the development of atrial remodeling underlying the AF substrate.
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Affiliation(s)
- Na Li
- Cardiovascular Research Institute, Department of Molecular Physiology&Biophysics, Baylor College of Medicine, Houston, TX
| | - David Y Chiang
- Cardiovascular Research Institute, Department of Molecular Physiology&Biophysics, Baylor College of Medicine, Houston, TX.,TBMM program, Baylor College of Medicine, Houston, TX
| | - Sufen Wang
- Department of Cardiology, The Methodist Hospital, Houston, TX
| | - Qiongling Wang
- Cardiovascular Research Institute, Department of Molecular Physiology&Biophysics, Baylor College of Medicine, Houston, TX
| | - Liang Sun
- Cardiovascular Research Institute, Department of Molecular Physiology&Biophysics, Baylor College of Medicine, Houston, TX
| | - Niels Voigt
- Institute of Pharmacology, Faculty of Medicine, University Duisburg-Essen, Essen, Germany.,Division of Experimental Cardiology, Heidelberg University, Mannheim, Germany
| | - Jonathan L Respress
- Cardiovascular Research Institute, Department of Molecular Physiology&Biophysics, Baylor College of Medicine, Houston, TX
| | - Sameer Ather
- Cardiovascular Research Institute, Department of Molecular Physiology&Biophysics, Baylor College of Medicine, Houston, TX
| | - Darlene G Skapura
- Cardiovascular Research Institute, Department of Molecular Physiology&Biophysics, Baylor College of Medicine, Houston, TX
| | - Valerie K Jordan
- Cardiovascular Research Institute, Department of Molecular Physiology&Biophysics, Baylor College of Medicine, Houston, TX
| | - Frank T Horrigan
- Cardiovascular Research Institute, Department of Molecular Physiology&Biophysics, Baylor College of Medicine, Houston, TX
| | - Wilhelm Schmitz
- Institute of Pharmacology and Toxicology, University of Münster, Germany
| | - Frank U Müller
- Institute of Pharmacology and Toxicology, University of Münster, Germany
| | - Miguel Valderrabano
- Division of Experimental Cardiology, Heidelberg University, Mannheim, Germany
| | - Stanley Nattel
- Department of Medicine, Montreal Heart Institute and Université de Montréal, Quebec, Canada
| | - Dobromir Dobrev
- Institute of Pharmacology, Faculty of Medicine, University Duisburg-Essen, Essen, Germany.,Division of Experimental Cardiology, Heidelberg University, Mannheim, Germany
| | - Xander H T Wehrens
- Cardiovascular Research Institute, Department of Molecular Physiology&Biophysics, Baylor College of Medicine, Houston, TX.,Department of Medicine.Cardiology), Baylor College of Medicine, Houston, TX
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50
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Gillis AM, Krahn AD, Skanes AC, Nattel S. Management of Atrial Fibrillation in the Year 2033: New Concepts, Tools, and Applications Leading to Personalized Medicine. Can J Cardiol 2013; 29:1141-6. [DOI: 10.1016/j.cjca.2013.07.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Revised: 07/10/2013] [Accepted: 07/11/2013] [Indexed: 10/26/2022] Open
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