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Shoemaker MB, Yoneda ZT, Crawford DM, Akers WS, Richardson T, Montgomery JA, Phillips S, Shyr Y, Saavedra P, Estrada J, Kanagasundram A, Shen ST, Michaud G, Crossley G, Ellis CR, Knollmann BC. A Mechanistic Clinical Trial Using ( R)- Versus (S)-Propafenone to Test RyR2 (Ryanodine Receptor) Inhibition for the Prevention of Atrial Fibrillation Induction. Circ Arrhythm Electrophysiol 2022; 15:e010713. [PMID: 36166682 PMCID: PMC9588733 DOI: 10.1161/circep.121.010713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 08/16/2022] [Indexed: 11/16/2022]
Abstract
BACKGROUND Experimental data suggest ryanodine receptor-mediated intracellular calcium leak is a mechanism for atrial fibrillation (AF), but evidence in humans is still needed. Propafenone is composed of two enantiomers that are equally potent sodium-channel blockers; however, (R)-propafenone is an ryanodine receptor inhibitor whereas (S)-propafenone is not. This study tested the hypothesis that ryanodine receptor inhibition with (R)-propafenone prevents induction of AF compared to (S)-propafenone or placebo in patients referred for AF ablation. METHODS Participants were randomized 4:4:1 to a one-time intravenous dose of (R)-propafenone, (S)-propafenone, or placebo. The study drug was given at the start of the procedure and an AF induction protocol using rapid atrial pacing was performed before ablation. The primary endpoint was 30 s of AF or atrial flutter. RESULTS A total of 193 participants were enrolled and 165 (85%) completed the study protocol (median age: 63 years, 58% male, 95% paroxysmal AF). Sustained AF and/or atrial flutter was induced in 60 participants (84.5%) receiving (R)-propafenone, 60 (80.0%) receiving (S)-propafenone group, and 12 (63.2%) receiving placebo. Atrial flutter occurred significantly more often in the (R)-propafenone (N=23, 32.4%) and (S)-propafenone (N=26, 34.7%) groups compared to placebo (N=1, 5.3%, P=0.029). There was no significant difference between (R)-propafenone and (S)-propafenone for the primary outcome of AF and/or atrial flutter induction in univariable (P=0.522) or multivariable analysis (P=0.199, adjusted for age and serum drug level). CONCLUSIONS There is no difference in AF inducibility between (R)-propafenone and (S)-propafenone at clinically relevant concentrations. These results are confounded by a high rate of inducible atrial flutter due to sodium-channel blockade. REGISTRATION https://clinicaltrials.gov; Unique Identifier: NCT02710669.
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Affiliation(s)
- M. Benjamin Shoemaker
- Division of Cardiology, Department of Medicine, Vanderbilt University Medical Center
| | - Zachary T. Yoneda
- Division of Cardiology, Department of Medicine, Vanderbilt University Medical Center
| | - Diane M. Crawford
- Division of Cardiology, Department of Medicine, Vanderbilt University Medical Center
| | - Wendell S. Akers
- Department of Pharmacology, Vanderbilt University School of Medicine
- Department of Pharmaceutical Sciences, Lipscomb University College of Pharmacy, Nashville, TN
| | - Travis Richardson
- Division of Cardiology, Department of Medicine, Vanderbilt University Medical Center
| | - Jay A. Montgomery
- Division of Cardiology, Department of Medicine, Vanderbilt University Medical Center
| | - Sharon Phillips
- Department of Biostatistics, Vanderbilt University School of Medicine
| | - Yu Shyr
- Department of Biostatistics, Vanderbilt University School of Medicine
| | - Pablo Saavedra
- Division of Cardiology, Department of Medicine, Vanderbilt University Medical Center
| | - J.C. Estrada
- Division of Cardiology, Department of Medicine, Vanderbilt University Medical Center
| | - Arvindh Kanagasundram
- Division of Cardiology, Department of Medicine, Vanderbilt University Medical Center
| | - Sharon T. Shen
- Division of Cardiology, Department of Medicine, Vanderbilt University Medical Center
| | - Greg Michaud
- Division of Cardiology, Department of Medicine, Vanderbilt University Medical Center
| | - George Crossley
- Division of Cardiology, Department of Medicine, Vanderbilt University Medical Center
| | - Christopher R. Ellis
- Division of Cardiology, Department of Medicine, Vanderbilt University Medical Center
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2
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Jost N, Christ T, Magyar J. New Strategies for the Treatment of Atrial Fibrillation. Pharmaceuticals (Basel) 2021; 14:ph14090926. [PMID: 34577626 PMCID: PMC8466466 DOI: 10.3390/ph14090926] [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: 06/02/2021] [Revised: 09/07/2021] [Accepted: 09/08/2021] [Indexed: 12/19/2022] Open
Abstract
Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia in the clinical practice. It significantly contributes to the morbidity and mortality of the elderly population. Over the past 25-30 years intense effort in basic research has advanced the understanding of the relationship between the pathophysiology of AF and atrial remodelling. Nowadays it is clear that the various forms of atrial remodelling (electrical, contractile and structural) play crucial role in initiating and maintaining the persistent and permanent types of AF. Unlike in ventricular fibrillation, in AF rapid ectopic firing originating from pulmonary veins and re-entry mechanism may induce and maintain (due to atrial remodelling) this complex cardiac arrhythmia. The present review presents and discusses in detail the latest knowledge on the role of remodelling in AF. Special attention is paid to novel concepts and pharmacological targets presumably relevant to the drug treatment of atrial fibrillation.
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Affiliation(s)
- Norbert Jost
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, 6725 Szeged, Hungary
- Department of Pharmacology and Pharmacotherapy, Interdisciplinary Excellence Centre, University of Szeged, 6725 Szeged, Hungary
- ELKH-SZTE Research Group for Cardiovascular Pharmacology, Eötvös Loránd Research Network, 6725 Szeged, Hungary
- Correspondence:
| | - Torsten Christ
- Institute of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany;
- DZHK (German Center for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, 20246 Hamburg, Germany
| | - János Magyar
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary;
- Department of Sport Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
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3
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Benz AP, Hohnloser SH. Is there a role for verapamil beyond rate control in paroxysmal atrial fibrillation? Europace 2021; 24:355-356. [PMID: 34499716 DOI: 10.1093/europace/euab225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 08/06/2021] [Indexed: 11/15/2022] Open
Affiliation(s)
- Alexander P Benz
- Department of Cardiology, Cardiology I, University Medical Center Mainz, Johannes Gutenberg-University, Mainz, Germany.,Population Health Research Institute, Hamilton Health Sciences and McMaster University, Hamilton, Ontario, Canada
| | - Stefan H Hohnloser
- Department of Cardiology, J. W. Goethe University, Theodor Stern Kai 7, 60590 Frankfurt, Germany.,Center of Thrombosis and Hemostasis, Gutenberg-University Mainz, Mainz, Germany
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4
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Pabel S, Ahmad S, Tirilomis P, Stehle T, Mustroph J, Knierim M, Dybkova N, Bengel P, Holzamer A, Hilker M, Streckfuss-Bömeke K, Hasenfuss G, Maier LS, Sossalla S. Inhibition of Na V1.8 prevents atrial arrhythmogenesis in human and mice. Basic Res Cardiol 2020; 115:20. [PMID: 32078054 PMCID: PMC7033079 DOI: 10.1007/s00395-020-0780-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Accepted: 02/10/2020] [Indexed: 12/19/2022]
Abstract
Pharmacologic approaches for the treatment of atrial arrhythmias are limited due to side effects and low efficacy. Thus, the identification of new antiarrhythmic targets is of clinical interest. Recent genome studies suggested an involvement of SCN10A sodium channels (NaV1.8) in atrial electrophysiology. This study investigated the role and involvement of NaV1.8 (SCN10A) in arrhythmia generation in the human atria and in mice lacking NaV1.8. NaV1.8 mRNA and protein were detected in human atrial myocardium at a significant higher level compared to ventricular myocardium. Expression of NaV1.8 and NaV1.5 did not differ between myocardium from patients with atrial fibrillation and sinus rhythm. To determine the electrophysiological role of NaV1.8, we investigated isolated human atrial cardiomyocytes from patients with sinus rhythm stimulated with isoproterenol. Inhibition of NaV1.8 by A-803467 or PF-01247324 showed no effects on the human atrial action potential. However, we found that NaV1.8 significantly contributes to late Na+ current and consequently to an increased proarrhythmogenic diastolic sarcoplasmic reticulum Ca2+ leak in human atrial cardiomyocytes. Selective pharmacological inhibition of NaV1.8 potently reduced late Na+ current, proarrhythmic diastolic Ca2+ release, delayed afterdepolarizations as well as spontaneous action potentials. These findings could be confirmed in murine atrial cardiomyocytes from wild-type mice and also compared to SCN10A-/- mice (genetic ablation of NaV1.8). Pharmacological NaV1.8 inhibition showed no effects in SCN10A-/- mice. Importantly, in vivo experiments in SCN10A-/- mice showed that genetic ablation of NaV1.8 protects against atrial fibrillation induction. This study demonstrates that NaV1.8 is expressed in the murine and human atria and contributes to late Na+ current generation and cellular arrhythmogenesis. Blocking NaV1.8 selectively counteracts this pathomechanism and protects against atrial arrhythmias. Thus, our translational study reveals a new selective therapeutic target for treating atrial arrhythmias.
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Affiliation(s)
- Steffen Pabel
- Department of Internal Medicine II, University Medical Center Regensburg, Franz-Josef-Strauß-Allee 11, 93053, Regensburg, Germany
| | - Shakil Ahmad
- Department of Internal Medicine II, University Medical Center Regensburg, Franz-Josef-Strauß-Allee 11, 93053, Regensburg, Germany
- Clinic for Cardiology and Pneumology, Georg-August University Göttingen, Robert Koch Str. 40, 37075, Göttingen, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Göttingen, Robert Koch Str. 40, 37075, Göttingen, Germany
| | - Petros Tirilomis
- Clinic for Cardiology and Pneumology, Georg-August University Göttingen, Robert Koch Str. 40, 37075, Göttingen, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Göttingen, Robert Koch Str. 40, 37075, Göttingen, Germany
| | - Thea Stehle
- Department of Internal Medicine II, University Medical Center Regensburg, Franz-Josef-Strauß-Allee 11, 93053, Regensburg, Germany
| | - Julian Mustroph
- Department of Internal Medicine II, University Medical Center Regensburg, Franz-Josef-Strauß-Allee 11, 93053, Regensburg, Germany
| | - Maria Knierim
- Clinic for Cardiology and Pneumology, Georg-August University Göttingen, Robert Koch Str. 40, 37075, Göttingen, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Göttingen, Robert Koch Str. 40, 37075, Göttingen, Germany
| | - Nataliya Dybkova
- Clinic for Cardiology and Pneumology, Georg-August University Göttingen, Robert Koch Str. 40, 37075, Göttingen, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Göttingen, Robert Koch Str. 40, 37075, Göttingen, Germany
| | - Philipp Bengel
- Clinic for Cardiology and Pneumology, Georg-August University Göttingen, Robert Koch Str. 40, 37075, Göttingen, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Göttingen, Robert Koch Str. 40, 37075, Göttingen, Germany
| | - Andreas Holzamer
- Department of Cardiothoracic Surgery, University Medical Center Regensburg, Franz-Josef-Strauß-Allee 11, 93053, Regensburg, Germany
| | - Michael Hilker
- Department of Cardiothoracic Surgery, University Medical Center Regensburg, Franz-Josef-Strauß-Allee 11, 93053, Regensburg, Germany
| | - Katrin Streckfuss-Bömeke
- Clinic for Cardiology and Pneumology, Georg-August University Göttingen, Robert Koch Str. 40, 37075, Göttingen, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Göttingen, Robert Koch Str. 40, 37075, Göttingen, Germany
| | - Gerd Hasenfuss
- Clinic for Cardiology and Pneumology, Georg-August University Göttingen, Robert Koch Str. 40, 37075, Göttingen, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Göttingen, Robert Koch Str. 40, 37075, Göttingen, Germany
| | - Lars S Maier
- Department of Internal Medicine II, University Medical Center Regensburg, Franz-Josef-Strauß-Allee 11, 93053, Regensburg, Germany
| | - Samuel Sossalla
- Department of Internal Medicine II, University Medical Center Regensburg, Franz-Josef-Strauß-Allee 11, 93053, Regensburg, Germany.
- Clinic for Cardiology and Pneumology, Georg-August University Göttingen, Robert Koch Str. 40, 37075, Göttingen, Germany.
- DZHK (German Centre for Cardiovascular Research), Partner Site Göttingen, Robert Koch Str. 40, 37075, Göttingen, Germany.
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5
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Gorenek B, Pelliccia A, Benjamin EJ, Boriani G, Crijns HJ, Fogel RI, Van Gelder IC, Halle M, Kudaiberdieva G, Lane DA, Larsen TB, Lip GYH, Løchen ML, Marín F, Niebauer J, Sanders P, Tokgozoglu L, Vos MA, Van Wagoner DR, Fauchier L, Savelieva I, Goette A, Agewall S, Chiang CE, Figueiredo M, Stiles M, Dickfeld T, Patton K, Piepoli M, Corra U, Marques-Vidal PM, Faggiano P, Schmid JP, Abreu A. European Heart Rhythm Association (EHRA)/European Association of Cardiovascular Prevention and Rehabilitation (EACPR) position paper on how to prevent atrial fibrillation endorsed by the Heart Rhythm Society (HRS) and Asia Pacific Heart Rhythm Society (APHRS). Europace 2018; 19:190-225. [PMID: 28175283 DOI: 10.1093/europace/euw242] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Affiliation(s)
| | | | | | | | - Harry J Crijns
- Maastricht University Medical Centre, Maastricht, The Netherlands
| | | | | | - Martin Halle
- Prevention and Sports Medicine, Technical University Munich, München, Germany
| | | | | | | | | | - Maja-Lisa Løchen
- University of Birmingham, Birmingham, UK.,Aalborg University Hospital, Aalborg, Denmark
| | | | - Josef Niebauer
- Paracelsus Medical University Salzburg, Salzburg, Austria
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Ugo Corra
- Irccs Rehabilitation Medical Center, Veruno, Italy
| | | | | | | | - Ana Abreu
- Hospital de Santa Marta, Lisboa, Portugal
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6
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Mattsson N, Kumarathurai P, Larsen BS, Nielsen OW, Sajadieh A. Mild Hypokalemia and Supraventricular Ectopy Increases the Risk of Stroke in Community-Dwelling Subjects. Stroke 2017; 48:537-543. [PMID: 28174323 DOI: 10.1161/strokeaha.116.015439] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 12/05/2016] [Accepted: 12/13/2016] [Indexed: 12/19/2022]
Abstract
BACKGROUND AND PURPOSE Stroke is independently associated with the common conditions of hypokalemia and supraventricular ectopy, and we hypothesize that the combination of excessive supraventricular ectopic activity and hypokalemia has a synergistic impact on the prognosis in terms of stroke in the general population. METHODS Subjects (55-75 years old) from the Copenhagen Holter Study cohort (N=671) with no history of atrial fibrillation or stroke were studied-including baseline values of potassium and ambulatory 48-hour Holter monitoring. Excessive supraventricular ectopic activity is defined as ≥30 premature atrial complexes per hour or any episodes of runs of ≥20. Hypokalemia was defined as plasma-potassium ≤3.6 mmol/L. The primary end point was ischemic stroke. Cox models were used. RESULTS Hypokalemia was mild (mean, 3.4 mmol/L; range, 2.7-3.6). Hypokalemic subjects were older (67.0±6.94 versus 64.0±6.66 years; P<0.0001) and more hypertensive (165.1±26.1 versus 154.6±23.5 mm Hg; P<0.0001). Median follow-up time was 14.4 years (Q1-Q3, 9.4-14.7 years). The incidence of stroke was significantly higher in the hypokalemic group (hazard ratio, 1.84; 95% confidence interval, 1.04-3.28) after covariate adjustments, as well as in a competing risk analysis with death (hazard ratio, 1.51; 95% confidence interval, 1.12-2.04). Excessive supraventricular ectopic activity was also associated with stroke (hazard ratio, 2.23; 95% confidence interval, 1.33-3.76). The combination of hypokalemia and excessive supraventricular ectopic activity increased the risk of events synergistically. Stroke rate was 93 per 1000 patient-year (P<0.0001) in this group (n=17) compared with 6.9 (n=480); 11 (n=81), and 13 (n=93) per 1000 patient-year in the groups without the combination. CONCLUSIONS The combination of hypokalemia and excessive supraventricular ectopy carries a poor prognosis in terms of stroke.
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Affiliation(s)
- Nick Mattsson
- From the Department of Cardiology, Copenhagen University Hospital of Bispebjerg, Denmark.
| | - Preman Kumarathurai
- From the Department of Cardiology, Copenhagen University Hospital of Bispebjerg, Denmark
| | - Bjørn Strøier Larsen
- From the Department of Cardiology, Copenhagen University Hospital of Bispebjerg, Denmark
| | - Olav Wendelboe Nielsen
- From the Department of Cardiology, Copenhagen University Hospital of Bispebjerg, Denmark
| | - Ahmad Sajadieh
- From the Department of Cardiology, Copenhagen University Hospital of Bispebjerg, Denmark
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7
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Gorenek B, Pelliccia A, Benjamin EJ, Boriani G, Crijns HJ, Fogel RI, Van Gelder IC, Halle M, Kudaiberdieva G, Lane DA, Bjerregaard Larsen T, Lip GYH, Løchen ML, Marin F, Niebauer J, Sanders P, Tokgozoglu L, Vos MA, Van Wagoner DR, Fauchier L, Savelieva I, Goette A, Agewall S, Chiang CE, Figueiredo M, Stiles M, Dickfeld T, Patton K, Piepoli M, Corra U, Manuel Marques-Vidal P, Faggiano P, Schmid JP, Abreu A. European Heart Rhythm Association (EHRA)/European Association of Cardiovascular Prevention and Rehabilitation (EACPR) position paper on how to prevent atrial fibrillation endorsed by the Heart Rhythm Society (HRS) and Asia Pacific Heart Rhythm Society (APHRS). Eur J Prev Cardiol 2017; 24:4-40. [PMID: 27815538 PMCID: PMC5427484 DOI: 10.1177/2047487316676037] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
| | | | | | | | - Harry J Crijns
- Maastricht University Medical Centre, Maastricht, The Netherlands
| | | | | | - Martin Halle
- Prevention and Sports Medicine, Technical University Munich, München, Germany
| | | | | | | | | | - Maja-Lisa Løchen
- UiT The Arctic University of Norway, Tromso, Norway
- Mary MacKillop Institute for Health Research, Centre for Research Excellence to Reduce Inequality in Heart Disease, Australian Catholic University, Melbourne, Australia
| | | | - Josef Niebauer
- Paracelsus Medical University Salzburg, Salzburg, Austria
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Ugo Corra
- Irccs Rehabilitation Medical Center, Veruno, Italy
| | | | | | | | - Ana Abreu
- Hospital de Santa Marta, Lisboa, Portugal
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8
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Voigt N, Heijman J, Dobrev D. New antiarrhythmic targets in atrial fibrillation. Future Cardiol 2015; 11:645-54. [PMID: 26609872 DOI: 10.2217/fca.15.67] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Atrial fibrillation (AF) is the most common cardiac arrhythmia in developed countries. AF is associated with increased mortality and morbidity due to thromboembolism, stroke and worsening of pre-existing heart failure. Currently available pharmacological therapies for AF suffer from unsatisfying efficacy and/or are associated with major side effects such as bleeding complications or proarrhythmia. These limitations largely result from the fact that most of the currently available drugs were developed on an empirical basis, without precise knowledge of the molecular mechanisms underlying the arrhythmia. During the last decade substantial progress has been made in understanding the molecular mechanisms contributing to the initiation and maintenance of AF. This knowledge is expected to stimulate the development of safer and more effective drugs. Here, we review new antiarrhythmic drug targets, which have emerged based on this increasing knowledge about the molecular mechanisms of AF.
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Affiliation(s)
- Niels Voigt
- Faculty of Medicine, Institute of Pharmacology, University Duisburg-Essen, Hufelandstr 55, 45122 Essen, Germany
| | - Jordi Heijman
- Faculty of Medicine, Institute of Pharmacology, University Duisburg-Essen, Hufelandstr 55, 45122 Essen, Germany
| | - Dobromir Dobrev
- Faculty of Medicine, Institute of Pharmacology, University Duisburg-Essen, Hufelandstr 55, 45122 Essen, Germany
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Simulation of Ectopic Pacemakers in the Heart: Multiple Ectopic Beats Generated by Reentry inside Fibrotic Regions. BIOMED RESEARCH INTERNATIONAL 2015; 2015:713058. [PMID: 26583127 PMCID: PMC4637158 DOI: 10.1155/2015/713058] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2015] [Revised: 05/08/2015] [Accepted: 05/17/2015] [Indexed: 11/18/2022]
Abstract
The inclusion of nonconducting media, mimicking cardiac fibrosis, in two models of cardiac tissue produces the formation of ectopic beats. The fraction of nonconducting media in comparison with the fraction of healthy myocytes and the topological distribution of cells determines the probability of ectopic beat generation. First, a detailed subcellular microscopic model that accounts for the microstructure of the cardiac tissue is constructed and employed for the numerical simulation of action potential propagation. Next, an equivalent discrete model is implemented, which permits a faster integration of the equations. This discrete model is a simplified version of the microscopic model that maintains the distribution of connections between cells. Both models produce similar results when describing action potential propagation in homogeneous tissue; however, they slightly differ in the generation of ectopic beats in heterogeneous tissue. Nevertheless, both models present the generation of reentry inside fibrotic tissues. This kind of reentry restricted to microfibrosis regions can result in the formation of ectopic pacemakers, that is, regions that will generate a series of ectopic stimulus at a fast pacing rate. In turn, such activity has been related to trigger fibrillation in the atria and in the ventricles in clinical and animal studies.
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10
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Mattsson N, Sadjadieh G, Kumarathurai P, Nielsen OW, Køber L, Sajadieh A. Ambulatory cardiac arrhythmias in relation to mild hypokalaemia and prognosis in community dwelling middle-aged and elderly subjects. Europace 2015; 18:585-91. [PMID: 26293625 DOI: 10.1093/europace/euv204] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 05/13/2015] [Indexed: 11/13/2022] Open
Abstract
AIMS Severe hypokalaemia can aggravate arrhythmia tendency and prognosis, but less is known about risk of mild hypokalaemia, which is a frequent finding. We examined the associations between mild hypokalaemia and ambulatory cardiac arrhythmias and their prognosis. METHODS AND RESULTS Subjects from the cohort of the 'Copenhagen Holter Study' (n = 671), with no history of manifest cardiovascular (CV) disease or stroke, were studied. All had laboratory tests and 48-h ambulatory electrocardiogram (ECG) recording. The median follow-up was 6.3 years. p-Potassium was inversely associated with frequency of premature ventricular complexes (PVCs) especially in combination with diuretic treatment (r = -0.22, P = 0.015). Hypokalaemia was not associated with supraventricular arrhythmias. Subjects at lowest quintile of p-potassium (mean 3.42, range 2.7-3.6 mmol/L) were defined as hypokalaemic. Cardiovascular mortality was higher in the hypokalaemic group (hazard ratio and 95% confidence intervals: 2.62 (1.11-6.18) after relevant adjustments). Hypokalaemia in combination with excessive PVC worsened the prognosis synergistically; event rates: 83 per 1000 patient-year in subjects with both abnormalities, 10 and 15 per 1000 patient-year in those with one abnormality, and 3 per 1000 patient-year in subjects with no abnormality. One variable combining hypokalaemia with excessive supraventricular arrhythmias gave similar results in univariate analysis, but not after multivariate adjustments. CONCLUSION In middle-aged and elderly subjects with no manifest heart disease, mild hypokalaemia is associated with increased rate of ventricular but not supraventricular arrhythmias. Hypokalaemia interacts synergistically with increased ventricular ectopy to increase the risk of adverse events.
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Affiliation(s)
- Nick Mattsson
- Department of Cardiology, Copenhagen University Hospital of Bispebjerg, Bispebjerg Bakke 23, 2400 Copenhagen NV, Denmark
| | - Golnaz Sadjadieh
- Department of Cardiology, Copenhagen University Hospital of Rigshospitalet, Copenhagen, Denmark
| | - Preman Kumarathurai
- Department of Cardiology, Copenhagen University Hospital of Bispebjerg, Bispebjerg Bakke 23, 2400 Copenhagen NV, Denmark
| | - Olav Wendelboe Nielsen
- Department of Cardiology, Copenhagen University Hospital of Bispebjerg, Bispebjerg Bakke 23, 2400 Copenhagen NV, Denmark
| | - Lars Køber
- Department of Cardiology, Copenhagen University Hospital of Rigshospitalet, Copenhagen, Denmark
| | - Ahmad Sajadieh
- Department of Cardiology, Copenhagen University Hospital of Bispebjerg, Bispebjerg Bakke 23, 2400 Copenhagen NV, Denmark
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Lau DH, Volders PGA, Kohl P, Prinzen FW, Zaza A, Kaab S, Oto A, Schotten U. Opportunities and challenges of current electrophysiology research: a plea to establish 'translational electrophysiology' curricula. Europace 2015; 17:825-33. [DOI: 10.1093/europace/euu301] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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12
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Voigt N, Dobrev D. The biology of human pulmonary veins: Does it help us to better understand AF pathophysiology in patients? Heart Rhythm 2013; 10:392-3. [DOI: 10.1016/j.hrthm.2012.12.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Indexed: 02/06/2023]
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