Recent advances in the molecular pathophysiology of atrial fibrillation
01 Aug 2011-Journal of Clinical Investigation (American Society for Clinical Investigation)-Vol. 121, Iss: 8, pp 2955-2968
TL;DR: The ways in which cardiac disease states, extracardiac factors, and abnormal genetic control lead to the arrhythmia are discussed, including the potential therapeutic implications that might arise from an improved mechanistic understanding.
Abstract: Atrial fibrillation (AF) is an extremely common cardiac rhythm disorder that causes substantial morbidity and contributes to mortality. The mechanisms underlying AF are complex, involving both increased spontaneous ectopic firing of atrial cells and impulse reentry through atrial tissue. Over the past ten years, there has been enormous progress in understanding the underlying molecular pathobiology. This article reviews the basic mechanisms and molecular processes causing AF. We discuss the ways in which cardiac disease states, extracardiac factors, and abnormal genetic control lead to the arrhythmia. We conclude with a discussion of the potential therapeutic implications that might arise from an improved mechanistic understanding.
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TL;DR: This document summarizes current research, plans, and recommendations for future research, as well as providing a history of the field and some of the techniques used, currently in use, at the National Institutes of Health.
Abstract: Jeffrey L. Anderson, MD, FACC, FAHA, Chair
Jonathan L. Halperin, MD, FACC, FAHA, Chair-Elect
Nancy M. Albert, PhD, RN, FAHA
Biykem Bozkurt, MD, PhD, FACC, FAHA
Ralph G. Brindis, MD, MPH, MACC
Mark A. Creager, MD, FACC, FAHA[#][1]
Lesley H. Curtis, PhD, FAHA
David DeMets, PhD[#][1]
Robert A
6,967 citations
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Johns Hopkins University1, University of Barcelona2, St George's, University of London3, Taipei Veterans General Hospital4, Maastricht University5, Washington University in St. Louis6, Imperial College London7, University of Virginia8, Virginia Commonwealth University9, Thomas Jefferson University10, Beaumont Hospital11, University of Bordeaux12, Leipzig University13, University of Oklahoma14, University of Michigan15, Royal Melbourne Hospital16, University College Dublin17, Korea University18, University of Münster19, University of Birmingham20, University of Western Ontario21, Cleveland Clinic22, Harvard University23, University of Pennsylvania24, Northwestern University25, Université de Montréal26, Mayo Clinic27, Icahn School of Medicine at Mount Sinai28, University of California, Los Angeles29, National Yang-Ming University30, Loyola University Chicago31
TL;DR: This 2012 Consensus Statement is to provide a state-of-the-art review of the field of catheter and surgical ablation of AF and to report the findings of a Task Force, convened by the Heart Rhythm Society, the European Heart Rhythm Association, and the European Cardiac Arrhythmia Society and charged with defining the indications, techniques, and outcomes of this procedure.
Abstract: During the past decade, catheter ablation of atrial fibrillation (AF) has evolved rapidly from an investigational procedure to its current status as a commonly performed ablation procedure in many major hospitals throughout the world. Surgical ablation of AF, using either standard or minimally invasive techniques, is also performed in many major hospitals throughout the world.
In 2007, an initial Consensus Statement on Catheter and Surgical AF Ablation was developed as a joint effort of the Heart Rhythm Society, the European Heart Rhythm Association, and the European Cardiac Arrhythmia Society.1 The 2007 document was also developed in collaboration with the Society of Thoracic Surgeons and the American College of Cardiology. Since the publication of the 2007 document, there has been much learned about AF ablation, and the indications for these procedures have changed. Therefore the purpose of this 2012 Consensus Statement is to provide a state-of-the-art review of the field of catheter and surgical ablation of AF and to report the findings of a Task Force, convened by the Heart Rhythm Society, the European Heart Rhythm Association, and the European Cardiac Arrhythmia Society and charged with defining the indications, techniques, and outcomes of this procedure. Included within this document are recommendations pertinent to the design of clinical trials in the field of AF ablation, including definitions relevant to this topic.
This statement summarizes the opinion of the Task Force members based on an extensive literature review as well as their own experience. It is directed to all health care professionals who are involved in the care of patients with AF, particularly those who are undergoing, or are being considered for, catheter or surgical ablation procedures for AF. This statement is not intended to recommend or promote catheter ablation of AF. Rather the ultimate judgment regarding care of a particular patient …
2,754 citations
Additional excerpts
...5 mm), and then gradually decreases distally.(11,29,30)...
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TL;DR: The medical profession should play a central role in evaluating the evidence related to drugs, devices, and procedures for the detection, management, and prevention of disease.
Abstract: Preamble 2072
1. Introduction 2074
2. Clinical Characteristics and Evaluation of AF 2076
3. Thromboembolic Risk and Treatment 2077
4. Rate Control: Recommendations 2079
5. Rhythm Control: Recommendations 2080
6. Specific Patient Groups and AF: Recommendations 2086
7. Evidence Gaps and Future Research Directions 2089
References 2090
Appendix 1. Author Relationships With Industry and Other Entities (Relevant) 2095
Appendix 2. Reviewer Relationships With Industry and Other Entities (Relevant) 2097
Appendix 3. Initial Clinical Evaluation in Patients With AF 2104
The medical profession should play a central role in evaluating the evidence related to drugs, devices, and procedures for the detection, management, and prevention of disease. When properly applied, expert analysis of available data on the benefits and risks of these therapies and procedures can improve the quality of care, optimize patient outcomes, and favorably affect costs by focusing resources on the most effective strategies. An organized …
2,192 citations
Cites background from "Recent advances in the molecular pa..."
...mechanisms (29, 33, 34), such that AF represents a final common phenotype for multiple disease pathways and...
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Johns Hopkins University1, Leipzig University2, Korea University3, Yale University4, West Virginia University5, University of Barcelona6, St George's, University of London7, Indiana University8, National Yang-Ming University9, Cleveland Clinic10, Aarhus University11, University at Buffalo12, Imperial College London13, Primary Children's Hospital14, Erasmus University Rotterdam15, Yeshiva University16, Ghent University17, Baylor University18, Virginia Commonwealth University19, Harvard University20, Federal University of São Paulo21, University of California, San Francisco22, Beaumont Hospital23, Boston University24, University of Oklahoma25, University of Michigan26, Carlos III Health Institute27, University of Melbourne28, Saint Louis University29, Université de Montréal30, University of Pennsylvania31, McGill University32, Mayo Clinic33, Lahey Hospital & Medical Center34, Royal Adelaide Hospital35, University of Milan36, University of Toronto37, Loyola University Chicago38, Jikei University School of Medicine39
TL;DR: This 2017 Consensus Statement is to provide a state-of-the-art review of the field of catheter and surgical ablation of AF and to report the findings of a writing group, convened by these five international societies.
1,626 citations
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University of Pennsylvania1, Johns Hopkins University2, Mayo Clinic3, University of Barcelona4, St George's, University of London5, Maastricht University6, Cleveland Clinic7, University of Virginia8, Baylor University9, Virginia Commonwealth University10, Thomas Jefferson University11, Beaumont Hospital12, University of Bordeaux13, Leipzig University14, University of Oklahoma15, University of Michigan16, Royal Melbourne Hospital17, University College Dublin18, Korea University19, University of Birmingham20, University of Münster21, University of Western Ontario22, Imperial College London23, Harvard University24, Northwestern University25, National Yang-Ming University26, Washington University in St. Louis27, Université de Montréal28, Icahn School of Medicine at Mount Sinai29, University of California, Los Angeles30, Loyola University Chicago31
TL;DR: A report of the Heart Rhythm Society (HRS) Task Force on Catheter and Surgical Ablation of Atrial Fibrillation, developed in partnership with the European Heart Rhythm Association (EHRA), a registered branch of the European Society of Cardiology and the European Cardiac Arrhythmia Society (ECAS), was published in this paper.
1,271 citations
References
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TL;DR: The pulmonary veins are an important source of ectopic beats, initiating frequent paroxysms of atrial fibrillation and these foci respond to treatment with radio-frequency ablation.
Abstract: Background Atrial fibrillation, the most common sustained cardiac arrhythmia and a major cause of stroke, results from simultaneous reentrant wavelets. Its spontaneous initiation has not been studied. Methods We studied 45 patients with frequent episodes of atrial fibrillation (mean [±SD] duration, 344±326 minutes per 24 hours) refractory to drug therapy. The spontaneous initiation of atrial fibrillation was mapped with the use of multielectrode catheters designed to record the earliest electrical activity preceding the onset of atrial fibrillation and associated atrial ectopic beats. The accuracy of the mapping was confirmed by the abrupt disappearance of triggering atrial ectopic beats after ablation with local radio-frequency energy. Results A single point of origin of atrial ectopic beats was identified in 29 patients, two points of origin were identified in 9 patients, and three or four points of origin were identified in 7 patients, for a total of 69 ectopic foci. Three foci were in the right atrium...
7,487 citations
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TL;DR: Artificial maintenance of AF leads to a marked shortening of AERP, a reversion of its physiological rate adaptation, and an increase in rate, inducibility and stability of AF.
Abstract: Background In this study we tested the hypothesis that atrial fibrillation (AF) causes electrophysiological changes of the atrial myocardium which might explain the progressive nature of the arrhythmia. Methods and Results Twelve goats were chronically instrumented with multiple electrodes sutured to the epicardium of both atria. Two to 3 Weeks after implantation, the animals were connected to a fibrillation pacemaker which artificially maintained AF. Whereas during control episodes of AF were short lasting (6±3 seconds), artificial maintenance of AF resulted in a progressive increase in the duration of AF to become sustained (>24 hours) after 7.1±4.8 days (10 of 11 goats). During the first 24 hours of AF the median fibrillation interval shortened from 145±18 to 108±8 ms and the inducibility of AF by a single premature stimulus increased from 24% to 76%. The atrial effective refractory period (AERP) shortened from 146±19 to 95±20 ms (−35%) (S1S1, 400 ms). At high pacing rates the shortening was less (−12%...
3,430 citations
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TL;DR: The age-adjusted incidence of AF increased significantly in Olmsted County during 1980 to 2000 and the projected number of persons with AF for the United States will exceed 10 million by 2050, underscoring the urgent need for primary prevention strategies against AF development.
Abstract: Background— Limited data exist on trends in incidence of atrial fibrillation (AF). We assessed the community-based trends in AF incidence for 1980 to 2000 and provided prevalence projections to 2050. Methods and Results— The adult residents of Olmsted County, Minnesota, who had ECG-confirmed first AF in the period 1980 to 2000 (n=4618) were identified. Trends in age-adjusted incidence were determined and used to construct model-based prevalence estimates. The age- and sex-adjusted incidence of AF per 1000 person-years was 3.04 (95% CI, 2.78 to 3.31) in 1980 and 3.68 (95% CI, 3.42 to 3.95) in 2000. According to Poisson regression with adjustment for age and sex, incidence of AF increased significantly (P=0.014), with a relative increase of 12.6% (95% CI, 2.1 to 23.1) over 21 years. The increase in age-adjusted AF incidence did not differ between men and women (P=0.84). According to the US population projections by the US Census Bureau, the number of persons with AF is projected to be 12.1 million by 2050, ...
2,430 citations
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TL;DR: It is shown that microRNA-21 regulates the ERK–MAP kinase signalling pathway in cardiac fibroblasts, which has impacts on global cardiac structure and function and confirms miR-21 as a disease target in heart failure and establishes the therapeutic efficacy of microRNA therapeutic intervention in a cardiovascular disease setting.
Abstract: MicroRNAs comprise a broad class of small non-coding RNAs that control expression of complementary target messenger RNAs. Dysregulation of microRNAs by several mechanisms has been described in various disease states including cardiac disease. Whereas previous studies of cardiac disease have focused on microRNAs that are primarily expressed in cardiomyocytes, the role of microRNAs expressed in other cell types of the heart is unclear. Here we show that microRNA-21 (miR-21, also known as Mirn21) regulates the ERK-MAP kinase signalling pathway in cardiac fibroblasts, which has impacts on global cardiac structure and function. miR-21 levels are increased selectively in fibroblasts of the failing heart, augmenting ERK-MAP kinase activity through inhibition of sprouty homologue 1 (Spry1). This mechanism regulates fibroblast survival and growth factor secretion, apparently controlling the extent of interstitial fibrosis and cardiac hypertrophy. In vivo silencing of miR-21 by a specific antagomir in a mouse pressure-overload-induced disease model reduces cardiac ERK-MAP kinase activity, inhibits interstitial fibrosis and attenuates cardiac dysfunction. These findings reveal that microRNAs can contribute to myocardial disease by an effect in cardiac fibroblasts. Our results validate miR-21 as a disease target in heart failure and establish the therapeutic efficacy of microRNA therapeutic intervention in a cardiovascular disease setting.
2,206 citations
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TL;DR: It is concluded that miR-29 acts as a regulator of cardiac fibrosis and represents a potential therapeutic target for tissue fibrosis in general.
Abstract: Acute myocardial infarction (MI) due to coronary artery occlusion is accompanied by a pathological remodeling response that includes hypertrophic cardiac growth and fibrosis, which impair cardiac contractility. Previously, we showed that cardiac hypertrophy and heart failure are accompanied by characteristic changes in the expression of a collection of specific microRNAs (miRNAs), which act as negative regulators of gene expression. Here, we show that MI in mice and humans also results in the dysregulation of specific miRNAs, which are similar to but distinct from those involved in hypertrophy and heart failure. Among the MI-regulated miRNAs are members of the miR-29 family, which are down-regulated in the region of the heart adjacent to the infarct. The miR-29 family targets a cadre of mRNAs that encode proteins involved in fibrosis, including multiple collagens, fibrillins, and elastin. Thus, down-regulation of miR-29 would be predicted to derepress the expression of these mRNAs and enhance the fibrotic response. Indeed, down-regulation of miR-29 with anti-miRs in vitro and in vivo induces the expression of collagens, whereas over-expression of miR-29 in fibroblasts reduces collagen expression. We conclude that miR-29 acts as a regulator of cardiac fibrosis and represents a potential therapeutic target for tissue fibrosis in general.
1,715 citations