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Liu SH, Lin FJ, Kao YH, Chen PH, Lin YK, Lu YY, Chen YC, Chen YJ. Chronic Partial Sleep Deprivation Increased the Incidence of Atrial Fibrillation by Promoting Pulmonary Vein and Atrial Arrhythmogenesis in a Rodent Model. Int J Mol Sci 2024; 25:7619. [PMID: 39062858 PMCID: PMC11277294 DOI: 10.3390/ijms25147619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2024] [Revised: 07/08/2024] [Accepted: 07/09/2024] [Indexed: 07/28/2024] Open
Abstract
Sleep deprivation (SD) is a recognized risk factor for atrial fibrillation (AF), yet the precise molecular and electrophysiological mechanisms behind SD-induced AF are unclear. This study explores the electrical and structural changes that contribute to AF in chronic partial SD. We induced chronic partial SD in Wistar rats using a modified multiple-platform method. Echocardiography demonstrated impaired systolic and diastolic function in the left ventricle (LV) of the SD rats. The SD rats exhibited an elevated heart rate and a higher low-frequency to high-frequency ratio in a heart-rate variability analysis. Rapid transesophageal atrial pacing led to a higher incidence of AF and longer mean AF durations in the SD rats. Conventional microelectrode recordings showed accelerated pulmonary vein (PV) spontaneous activity in SD rats, along with a heightened occurrence of delayed after-depolarizations in the PV and left atrium (LA) induced by tachypacing and isoproterenol. A Western blot analysis showed reduced expression of G protein-coupled receptor kinase 2 (GRK2) in the LA of the SD rats. Chronic partial SD impairs LV function, promotes AF genesis, and increases PV and LA arrhythmogenesis, potentially attributed to sympathetic overactivity and reduced GRK2 expression. Targeting GRK2 signaling may offer promising therapeutic avenues for managing chronic partial SD-induced AF. Future investigations are mandatory to investigate the dose-response relationship between SD and AF genesis.
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Affiliation(s)
- Shuen-Hsin Liu
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan; (S.-H.L.)
- Division of Cardiology, Department of Internal Medicine, Shuang-Ho Hospital, Taipei Medical University, New Taipei City 235, Taiwan
- Taipei Heart Institute, Taipei Medical University, Taipei 110, Taiwan
| | - Fong-Jhih Lin
- Department of Biomedical Engineering, National Defense Medical Center, Taipei 11490, Taiwan
| | - Yu-Hsun Kao
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan; (S.-H.L.)
- Cardiovascular Research Center, Wan-Fang Hospital, Taipei Medical University, Taipei 116, Taiwan
| | - Pao-Huan Chen
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan; (S.-H.L.)
- Department of Psychiatry, Taipei Medical University Hospital, Taipei 110301, Taiwan
- Department of Psychiatry, School of Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan
| | - Yung-Kuo Lin
- Taipei Heart Institute, Taipei Medical University, Taipei 110, Taiwan
- Cardiovascular Research Center, Wan-Fang Hospital, Taipei Medical University, Taipei 116, Taiwan
- Division of Cardiology, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan
- Division of Cardiovascular Medicine, Department of Internal Medicine, Wan-Fang Hospital, Taipei Medical University, Taipei 116, Taiwan
| | - Yen-Yu Lu
- School of Medicine, College of Medicine, Fu Jen Catholic University, New Taipei City 24205, Taiwan
- Division of Cardiology, Department of Internal Medicine, Sijhih Cathay General Hospital, New Taipei City 221, Taiwan
| | - Yao-Chang Chen
- Department of Biomedical Engineering, National Defense Medical Center, Taipei 11490, Taiwan
| | - Yi-Jen Chen
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan; (S.-H.L.)
- Taipei Heart Institute, Taipei Medical University, Taipei 110, Taiwan
- Cardiovascular Research Center, Wan-Fang Hospital, Taipei Medical University, Taipei 116, Taiwan
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Kreimer F, Gotzmann M. Pacemaker-induced atrial fibrillation reconsidered-associations with different pacing sites and prevention approaches. Front Cardiovasc Med 2024; 11:1412283. [PMID: 38957332 PMCID: PMC11217490 DOI: 10.3389/fcvm.2024.1412283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2024] [Accepted: 06/05/2024] [Indexed: 07/04/2024] Open
Abstract
The incidence of atrial fibrillation (AF) is significantly higher in patients with pacemakers than in the general population, which could be due to patient characteristics and the diagnostic tool of the pacemaker in detecting atrial high-rate episodes and subclinical AF, but also to the pacemaker itself providing AF-promoting conditions. It is well known that high ventricular pacemaker burden increases the likelihood of AF occurrence. However, the sites of atrial and ventricular pacing may also influence the risk for AF. The conventional sites for atrial and ventricular pacing are in the right atrial appendage and in the right ventricular apex. However, growing evidence suggests that alternative pacing sites may be superior for the prevention of AF. Bachmann bundle pacing, for example, promotes interatrial excitation conduction, resulting in atrial synchronicity and a shorter total atrial activation time, which may be preventive for the occurrence of AF. Moreover, in recent years, new ventricular pacing sites have come into focus with His bundle and left bundle branch pacing. In addition to the hemodynamic and electrophysiological cardiac benefits, these new options may also offer benefits in the prevention of AF. This review provides an overview of pacing-induced AF mechanisms and the association with different pacing sites, as well as approaches for prevention of pacing-induced AF, highlighting different sites and modes of atrial pacing and the newer sites of ventricular pacing.
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Affiliation(s)
- Fabienne Kreimer
- Department of Cardiology and Rhythmology, St Josef Hospital Bochum, University Hospital of the Ruhr University Bochum, Bochum, Germany
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Liu Y, Zheng Y, Tse G, Bazoukis G, Letsas K, Goudis C, Korantzopoulos P, Li G, Liu T. Association between sick sinus syndrome and atrial fibrillation: A systematic review and meta-analysis. Int J Cardiol 2023; 381:20-36. [PMID: 37023861 DOI: 10.1016/j.ijcard.2023.03.066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 03/17/2023] [Accepted: 03/31/2023] [Indexed: 04/08/2023]
Abstract
AIMS Sick sinus syndrome (SSS) and atrial fibrillation (AF) frequently coexist and show a bidirectional relationship. This systematic review and meta-analysis aimed to decipher the precise relationship between SSS and AF, further exploring and comparing different therapy strategies on the occurrence or progression of AF in patients with SSS. METHODS AND RESULTS A systematic literature search was conducted until November 2022. A total of 35 articles with 37,550 patients were included. Patients with SSS were associated with new-onset AF compared to those without SSS. Catheter ablation was associated with a lower risk of AF recurrence, AF progression, all-cause mortality, stroke and hospitalization of heart failure compared to pacemaker therapy. Regarding the different pacing strategies for SSS, VVI/VVIR has higher risk of new-onset AF than DDD/DDDR. No significant difference was found between AAI/AAIR and DDD/DDDR, as well as between DDD/DDDR and minimal ventricular pacing (MVP) for AF recurrence. AAI/AAIR was associated with higher risk of all-cause mortality when compared to DDD/DDDR, but lower risk of cardiac death when compared to DDD/DDDR. Right atrial septum pacing was associated with a similar risk of new-onset AF or AF recurrence compared to right atrial appendage pacing. CONCLUSION SSS is associated with a higher risk of AF. For patients with both SSS and AF, catheter ablation should be considered. This meta-analysis re-emphasizes that high percentage of ventricular pacing should be avoided in patients with SSS in order to decrease AF burden and mortality.
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Affiliation(s)
- Ying Liu
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin 300211, China
| | - Yi Zheng
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin 300211, China
| | - Gary Tse
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin 300211, China; Kent and Medway Medical School, University of Kent and Canterbury Christ Church University, Canterbury, Kent, UK; School of Nursing and Health Studies, Hong Kong, Metropolitan University, Hong Kong, China
| | - George Bazoukis
- Department of Cardiology, Larnaca General Hospital, Inomenon Polition Amerikis, Larnaca, Cyprus; Department of Basic and Clinical Sciences, University of Nicosia Medical School, 2414 Nicosia, Cyprus
| | - Konstantinos Letsas
- Laboratory of Cardiac Electrophysiology, Onassis Cardiac Surgery Center, Athens, Greece
| | - Christos Goudis
- Department of Cardiology, Serres General Hospital, 45110 Serres, Greece
| | | | - Guangping Li
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin 300211, China
| | - Tong Liu
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin 300211, China.
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Lu YY, Lin FJ, Chen YC, Kao YH, Higa S, Chen SA, Chen YJ. Role of Endothelin-1 in Right Atrial Arrhythmogenesis in Rabbits with Monocrotaline-Induced Pulmonary Arterial Hypertension. Int J Mol Sci 2022; 23:ijms231910993. [PMID: 36232308 PMCID: PMC9569916 DOI: 10.3390/ijms231910993] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 09/06/2022] [Accepted: 09/15/2022] [Indexed: 12/03/2022] Open
Abstract
Atrial arrhythmias are considered prominent phenomena in pulmonary arterial hypertension (PAH) resulting from atrial electrical and structural remodeling. Endothelin (ET)-1 levels correlate with PAH severity and are associated with atrial remodeling and arrhythmia. In this study, hemodynamic measurement, western blot analysis, and histopathology were performed in the control and monocrotaline (MCT, 60 mg/kg)-induced PAH rabbits. Conventional microelectrodes were used to simultaneously record the electrical activity in the isolated sinoatrial node (SAN) and right atrium (RA) tissue preparations before and after ET-1 (10 nM) or BQ-485 (an ET-A receptor antagonist, 100 nM) perfusion. MCT-treated rabbits showed an increased relative wall thickness in the pulmonary arterioles, mean cell width, cross-sectional area of RV myocytes, and higher right ventricular systolic pressure, which were deemed to have PAH. Compared to the control, the spontaneous beating rate of SAN–RA preparations was faster in the MCT-induced PAH group, which can be slowed down by ET-1. MCT-induced PAH rabbits had a higher incidence of sinoatrial conduction blocks, and ET-1 can induce atrial premature beats or short runs of intra-atrial reentrant tachycardia. BQ 485 administration can mitigate ET-1-induced RA arrhythmogenesis in MCT-induced PAH. The RA specimens from MCT-induced PAH rabbits had a smaller connexin 43 and larger ROCK1 and phosphorylated Akt than the control, and similar PKG and Akt to the control. In conclusion, ET-1 acts as a trigger factor to interact with the arrhythmogenic substrate to initiate and maintain atrial arrhythmias in PAH. ET-1/ET-A receptor/ROCK signaling may be a target for therapeutic interventions to treat PAH-induced atrial arrhythmias.
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Affiliation(s)
- Yen-Yu Lu
- Division of Cardiology, Sijhih Cathay General Hospital, New Taipei City 22174, Taiwan
- School of Medicine, Fu-Jen Catholic University, New Taipei City 24257, Taiwan
| | - Fong-Jhih Lin
- Department of Biomedical Engineering, National Defense Medical Center, Taipei 11490, Taiwan
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei 11042, Taiwan
| | - Yao-Chang Chen
- Department of Biomedical Engineering, National Defense Medical Center, Taipei 11490, Taiwan
| | - Yu-Hsun Kao
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei 11042, Taiwan
- Department of Medical Education and Research, Wan Fang Hospital, Taipei Medical University, Taipei 11696, Taiwan
| | - Satoshi Higa
- Cardiac Electrophysiology and Pacing Laboratory, Division of Cardiovascular Medicine, Makiminato Central Hospital, Okinawa 901-2131, Japan
| | - Shih-Ann Chen
- Heart Rhythm Center, Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei 11217, Taiwan
- Cardiovascular Center, Taichung Veterans General Hospital, Taichung 40705, Taiwan
- Department of Post-Baccalaureate Medicine, College of Medicine, National Chung Hsing University, Taichung 40227, Taiwan
- Correspondence: (S.-A.C.); (Y.-J.C.)
| | - Yi-Jen Chen
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei 11042, Taiwan
- Cardiovascular Research Center, Wan Fang Hospital, Taipei Medical University, Taipei 11696, Taiwan
- Correspondence: (S.-A.C.); (Y.-J.C.)
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5
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Infeld M, Nicoli CD, Meagher S, Tompkins BJ, Wayne S, Irvine B, Betageri O, Habel N, Till S, Lobel J, Meyer M, Lustgarten DL. Clinical impact of Bachmann's bundle pacing defined by electrocardiographic criteria on atrial arrhythmia outcomes. Europace 2022; 24:1460-1468. [PMID: 35304608 DOI: 10.1093/europace/euac029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 02/18/2022] [Indexed: 11/12/2022] Open
Abstract
AIMS Evaluate whether Bachmann's bundle pacing (BBp) defined by electrocardiographic (ECG) criteria is associated with less atrial fibrillation/tachycardia (AF/AT) compared with anatomically defined right atrial septal pacing (RASp) and right atrial appendage pacing (RAAp). METHODS AND RESULTS This is a retrospective study comparing BBp with non-specific RASp and RAAp on new incidence, burden, and recurrence of AF/AT. We included patients who underwent atrial lead placement between 2006 and 2019 and received > 20% atrial pacing. BBp was defined by paced P-wave morphology and fluoroscopic lead position. Compared with RASp (n = 107) and RAAp (n = 108), AF/AT burden was lower in the BBp (n = 134) group by repeated measures ANOVA (P < 0.001). Over 2-year follow-up, AF/AT burden increased in the RASp (P < 0.01) and RAAp (P < 0.01) groups but did not significantly change in the BBp group (P = 0.91). Atrial arrhythmia burden was lower in the BBp group than the RASp and RAAp groups at 12-15, 18-21, and 24-27 months (P < 0.05) after pacemaker placement. Risk of AF/AT recurrence was lower in BBp than RASp (HR 0.43; P < 0.01) and RAAp patients (HR 0.29, P < 0.01). Risk of de novo AF/AT was also lower in BBp than in RASp (OR 0.12; P < 0.01) and RAAp patients (OR 0.20, P < 0.01). CONCLUSION Bachmann's bundle pacing defined using P-wave criteria was associated with decreased atrial arrhythmia burden, recurrence, and de novo incidence compared with right atrial septal pacing and right atrial appendage pacing.
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Affiliation(s)
- Margaret Infeld
- Department of Medicine, Larner College of Medicine, University of Vermont, 111 Colchester Avenue, Burlington, VT 05401, USA
| | - Charles D Nicoli
- Department of Medicine, Larner College of Medicine, University of Vermont, 111 Colchester Avenue, Burlington, VT 05401, USA
| | - Sean Meagher
- Department of Medicine, Larner College of Medicine, University of Vermont, 111 Colchester Avenue, Burlington, VT 05401, USA
| | - Bradley J Tompkins
- Department of Medicine, Larner College of Medicine, University of Vermont, 111 Colchester Avenue, Burlington, VT 05401, USA
| | - Shawn Wayne
- Department of Medicine, Larner College of Medicine, University of Vermont, 111 Colchester Avenue, Burlington, VT 05401, USA
| | - Benjamin Irvine
- Department of Medicine, Tulane University, New Orleans, Louisiana
| | - Omkar Betageri
- Department of Medicine, University of Florida, Gainesville, FL, USA
| | - Nicole Habel
- Department of Medicine, Larner College of Medicine, University of Vermont, 111 Colchester Avenue, Burlington, VT 05401, USA
| | - Sean Till
- Department of Medicine, Larner College of Medicine, University of Vermont, 111 Colchester Avenue, Burlington, VT 05401, USA
| | - Jennings Lobel
- Department of Medicine, Larner College of Medicine, University of Vermont, 111 Colchester Avenue, Burlington, VT 05401, USA
| | - Markus Meyer
- Department of Medicine, Lillehei Heart Institute, University of Minnesota, Minneapolis, MN, USA
| | - Daniel L Lustgarten
- Department of Medicine, Larner College of Medicine, University of Vermont, 111 Colchester Avenue, Burlington, VT 05401, USA
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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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Li RG, Xu YJ, Ye WG, Li YJ, Chen H, Qiu XB, Yang YQ, Bai D. Connexin45 (GJC1) loss-of-function mutation contributes to familial atrial fibrillation and conduction disease. Heart Rhythm 2021; 18:684-693. [PMID: 33429106 DOI: 10.1016/j.hrthm.2020.12.033] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 12/30/2020] [Accepted: 12/31/2020] [Indexed: 12/27/2022]
Abstract
BACKGROUND Atrial fibrillation (AF) represents the most common clinical cardiac arrhythmia and substantially increases the risk of cerebral stroke, heart failure, and death. Although causative genes for AF have been identified, the genetic determinants for AF remain largely unclear. OBJECTIVE This study aimed to investigate the molecular basis of AF in a Chinese kindred. METHODS A 4-generation family with autosomal-dominant AF and other arrhythmias (atrioventricular block, sinus bradycardia, and premature ventricular contractions) was recruited. Genome-wide scan with microsatellite markers and linkage analysis as well as whole-exome sequencing analysis were performed. Electrophysiological characteristics and subcellular localization of the AF-linked mutant were analyzed using dual whole-cell patch clamps and confocal microscopy, respectively. RESULTS A novel genetic locus for AF was mapped to chromosome 17q21.3, a 3.23-cM interval between markers D17S951 and D17S931, with a maximum 2-point logarithm of odds score of 4.2144 at marker D17S1868. Sequencing analysis revealed a heterozygous mutation in the mapping region, NM_005497.4:c.703A>T;p.(M235L), in the GJC1 gene encoding connexin45 (Cx45). The mutation cosegregated with AF in the family and was absent in 632 control individuals. The mutation decreased the coupling conductance in cell pairs (M235L/M235L, M235L/Cx45, M235L/Cx43, and M235L/Cx40), likely because of impaired subcellular localization. CONCLUSION This study defines a novel genetic locus for AF on chromosome 17q21.3 and reveals a loss-of-function mutation in GJC1 (Cx45) contributing to AF and other cardiac arrhythmias.
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Affiliation(s)
- Ruo-Gu Li
- Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Ying-Jia Xu
- Department of Cardiology, Shanghai Fifth People's Hospital, Fudan University, Shanghai, China
| | - Willy G Ye
- Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada
| | - Yan-Jie Li
- Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Honghong Chen
- Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada
| | - Xing-Biao Qiu
- Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Yi-Qing Yang
- Department of Cardiology, Shanghai Fifth People's Hospital, Fudan University, Shanghai, China; Cardiovascular Research Laboratory, Shanghai Fifth People's Hospital, Fudan University, Shanghai, China; Center Laboratory, Shanghai Fifth People's Hospital, Fudan University, Shanghai, China.
| | - Donglin Bai
- Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada.
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Chan CS, Lin YS, Lin YK, Chen YC, Kao YH, Hsu CC, Chen SA, Chen YJ. Atrial arrhythmogenesis in a rabbit model of chronic obstructive pulmonary disease. Transl Res 2020; 223:25-39. [PMID: 32438072 DOI: 10.1016/j.trsl.2020.04.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 03/25/2020] [Accepted: 04/16/2020] [Indexed: 02/02/2023]
Abstract
Chronic obstructive pulmonary disease (COPD) increases the risk of atrial fibrillation (AF), however, its arrhythmogenic mechanisms are unclear. This study investigated the effects of COPD on AF triggers (pulmonary veins, PVs) and substrates (atria), and their potential underlying mechanisms. Electrocardiographic, echocardiographic, and biochemical studies were conducted in control rabbits and rabbits with human leukocyte elastase (0.3 unit/kg)-induced COPD. Conventional microelectrode, Western blotting, and histological examinations were performed on PV, left atrium (LA), right atrium, and sinoatrial node (SAN) preparations from control rabbits and those with COPD. The rabbits with COPD had a higher incidence of atrial premature complexes, PV burst firing and delayed afterdepolarizations, higher sympathetic activity, larger LA, and faster PV spontaneous activity than did the control rabbits; but they exhibited a slower SAN beating rate. The LA of the rabbits with COPD had a shorter action potential duration and longer tachyarrhythmia induced by tachypacing (20 Hz) and isoproterenol (1 μM). Additionally, the rabbits with COPD had higher fibrosis in the PVs, LA, and SAN. H89 (10 μM), KN93 (1 μM), and KB-R7943 (10 μM) significantly suppressed burst firing and delayed afterdepolarizations in the PVs of the rabbits with COPD. Moreover, compared with the control rabbits, those with COPD had lower expression levels of the β1 adrenergic receptor, Cav 1.2, and Na+/Ca2+ exchanger in the PVs; Cav 1.2 in the LA; and hyperpolarization-activated cyclic nucleotide-gated K+ channel 4 in the SAN. COPD increases atrial arrhythmogenesis by modulating the distinctive electrophysiological characteristics of the PVs, LA, and SAN.
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Affiliation(s)
- Chao-Shun Chan
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - You Shuei Lin
- Department of Physiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Yung-Kuo Lin
- Division of Cardiology, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Yao-Chang Chen
- Department of Biomedical Engineering, National Defense Medical Center, Taipei, Taiwan
| | - Yu-Hsun Kao
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; Department of Medical Education and Research, Wan-Fang Hospital, Taipei Medical University, Taipei, Taiwan
| | - Chun-Chun Hsu
- School of Respiratory Therapy, College of Medicine, Taipei Medical University, Taipei, Taiwan; Division of Pulmonary Medicine, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University Hospital, Taipei, Taiwan
| | - Shih-Ann Chen
- Heart Rhythm Center, Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Yi-Jen Chen
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; Cardiovascular Research Center, Wan-Fang Hospital, Taipei Medical University, Taipei, Taiwan.
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9
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Chang JH, Cheng CC, Lu YY, Chen YC, Chen SA, Chen YJ. Trastuzumab increases pulmonary vein arrhythmogenesis through modulating pulmonary vein electrical and conduction properties via phosphatidylinositol 3-kinase signaling. IRANIAN JOURNAL OF BASIC MEDICAL SCIENCES 2020; 23:865-870. [PMID: 32774807 PMCID: PMC7395187 DOI: 10.22038/ijbms.2020.44651.10432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Objective(s): Drug-induced atrial fibrillation (AF) is considered an adverse effect of chemotherapeutic drugs. AF is a crucial risk factor for stroke, heart failure, myocardial infarction, and mortality. Pulmonary veins (PVs) are considered triggers inducing AF, and the sinoatrial node (SAN) may modulate PV activity and participate in AF genesis. AF was associated with early discontinuation of trastuzumab in patients with breast cancer. However, whether trastuzumab directly modulates the electrophysiological characteristics of PV and SAN remains unclear. Materials and Methods: ECG and conventional microelectrode system were used to record rabbit heart rhythm in vivo and electrical activities in vitro from isolated SAN, PV, and SAN-PV preparations. Results: Trastuzumab reduced the beating rate in isolated PV and SAN preparations at 1, 10, and 30 μM (particularly in isolated SAN preparations) and induced burst firings in isolated PV preparations at 10 μΜ. In addition, trastuzumab (10 μM) induced SAN-PV conduction block and burst firings, which were blocked by wortmannin (a PI3K inhibitor, 100 nM). Similarly, ECG recordings showed that acute intravenous administration of trastuzumab (10 mg/kg) reduced rabbit heart rates. Conclusion: Trastuzumab increased PV arrhythmogenesis through interfering with PI3K signaling, which may contribute to the genesis of AF.
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Affiliation(s)
- Jun-Hei Chang
- Department of Medical, Tri-Service General Hospital Songshan Branch, National Defense Medical Center, Taipei, Taiwan.,Department of Biomedical Engineering, National Defense Medical Center, Taipei, Taiwan
| | - Chen-Chuan Cheng
- Department of Cardiology, Chi-Mei Medical Center, Tainan, Taiwan
| | - Yen-Yu Lu
- Division of Cardiology, Department of Internal Medicine, Sijhih Cathay General Hospital, New Taipei City, Taiwan.,School of Medicine, College of Medicine, Fu-Jen Catholic University, New Taipei City, Taiwan
| | - Yao-Chang Chen
- Department of Biomedical Engineering, National Defense Medical Center, Taipei, Taiwan
| | - Shih-Ann Chen
- Heart Rhythm Center and Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Yi-Jen Chen
- Cardiovascular Research Center, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan.,Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
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10
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Lu YY, Cheng CC, Wu HJ, Lin YK, Chen YC, Chen SA, Chen YJ. Effects of ANP on pulmonary vein electrophysiology, Ca 2+ homeostasis and adrenergic arrhythmogenesis via PKA. Clin Exp Pharmacol Physiol 2019; 47:247-254. [PMID: 31637746 DOI: 10.1111/1440-1681.13199] [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: 08/14/2019] [Revised: 10/16/2019] [Accepted: 10/18/2019] [Indexed: 12/28/2022]
Abstract
Atrial fibrillation (AF) is the most common form of arrhythmia and increases the risk of stroke and heart failure (HF). Pulmonary veins (PVs) are important sources of triggers that generate AF, and calcium (Ca2+ ) overload participates in PV arrhythmogenesis. Neurohormonal activation is an important cause of AF. Higher atrial natriuretic peptide (ANP) level predicts paroxysmal AF occurrence in HF patients. However, it is not clear if ANP directly modulates electrophysiological characteristics and Ca2+ homeostasis in the PVs. Conventional microelectrodes, whole-cell patch-clamp, and the Fluo-3 fluorimetric ratio technique were performed using isolated rabbit PV preparations or single isolated PV cardiomyocytes before and after ANP administration. We found that ANP (1, 10, and 100 nmol/L) concentration-dependently decreased spontaneous activity in PV preparations. ANP (100 nmol/L) decreased isoproterenol (1 μmol/L)-induced PV spontaneous activity and burst firing. AP811 (100 nmol/L, NPR-C agonist), H89 (1μmol/L, PKA inhibitor) decreased isoproterenol-induced PV spontaneous activity or burst firing, but successive administration of ANP had no further effect on PV activity. KT5823 (1 μmol/L, PKG inhibitor) decreased isoproterenol-induced PV spontaneous activity but did not change isoproterenol-induced PV burst firing, whereas successive administration of ANP did not change isoproterenol-induced PV burst firing. ANP decreased intracellular Ca2+ transient and sarcoplasmic reticulum Ca2+ content in single PV cardiomyocytes. ANP decreased the late sodium current, L-type Ca2+ current, but did not change nickel-sensitive Na+ -Ca2+ exchanger current in single PV cardiomyocytes. In conclusion, ANP directly regulates PV electrophysiological characteristics and Ca2+ homeostasis and attenuates isoproterenol-induced arrhythmogenesis through NPR-C/cAMP/PKA signal pathway.
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Affiliation(s)
- Yen-Yu Lu
- Division of Cardiology, Department of Internal Medicine, Sijhih Cathay General Hospital, New Taipei City, Taiwan.,School of Medicine, Fu-Jen Catholic University, New Taipei City, Taiwan
| | | | - Hui-Jun Wu
- Graduate Institute of Physiology, National Defense Medical Center, Taipei, Taiwan
| | - Yung-Kuo Lin
- Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei City, Taiwan.,Division of Cardiology, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Yao-Chang Chen
- Department of Biomedical Engineering, National Defense Medical Center, Taipei, Taiwan
| | - Shih-Ann Chen
- Heart Rhythm Center and Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Yi-Jen Chen
- Cardiovascular Research Center, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan.,Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
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11
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Huang JH, Chen YC, Lu YY, Lin YK, Chen SA, Chen YJ. Arginine vasopressin modulates electrical activity and calcium homeostasis in pulmonary vein cardiomyocytes. J Biomed Sci 2019; 26:71. [PMID: 31530276 PMCID: PMC6747756 DOI: 10.1186/s12929-019-0564-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 09/10/2019] [Indexed: 02/06/2023] Open
Abstract
Background Atrial fibrillation (AF) frequently coexists with congestive heart failure (HF) and arginine vasopressin (AVP) V1 receptor antagonists are used to treat hyponatremia in HF. However, the role of AVP in HF-induced AF still remains unclear. Pulmonary veins (PVs) are central in the genesis of AF. The purpose of this study was to determine if AVP is directly involved in the regulation of PV electrophysiological properties and calcium (Ca2+) homeostasis as well as the identification of the underlying mechanisms. Methods Patch clamp, confocal microscopy with Fluo-3 fluorescence, and Western blot analyses were used to evaluate the electrophysiological characteristics, Ca2+ homeostasis, and Ca2+ regulatory proteins in isolated rabbit single PV cardiomyocytes incubated with and without AVP (1 μM), OPC 21268 (0.1 μM, AVP V1 antagonist), or OPC 41061 (10 nM, AVP V2 antagonist) for 4–6 h. Results AVP (0.1 and 1 μM)-treated PV cardiomyocytes had a faster beating rate (108 to 152%) than the control cells. AVP (1 μM) treated PV cardiomyocytes had higher late sodium (Na+) and Na+/Ca2+ exchanger (NCX) currents than control PV cardiomyocytes. AVP (1 μM) treated PV cardiomyocytes had smaller Ca2+i transients, and sarcoplasmic reticulum (SR) Ca2+ content as well as higher Ca2+ leak. However, combined AVP (1 μM) and OPC 21268 (0.1 μM) treated PV cardiomyocytes had a slower PV beating rate, larger Ca2+i transients and SR Ca2+ content, smaller late Na+ and NCX currents than AVP (1 μM)-treated PV cardiomyocytes. Western blot experiments showed that AVP (1 μM) treated PV cardiomyocytes had higher expression of NCX and p-CaMKII, and a higher ratio of p-CaMKII/CaMKII. Conclusions AVP increases PV arrhythmogenesis with dysregulated Ca2+ homeostasis through vasopressin V1 signaling.
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Affiliation(s)
- Jen-Hung Huang
- Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, 111 Hsin-Lung Road, Sec. 3, Taipei, 116, Taiwan.,Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Yao-Chang Chen
- Department of Biomedical Engineering, and Institute of Physiology, National Defense Medical Center, Taipei, Taiwan
| | - Yen-Yu Lu
- Division of Cardiology, Department of Internal Medicine, Sijhih Cathay General Hospital, New Taipei City, Taiwan.,School of Medicine, Fu-Jen Catholic University, New Taipei City, Taiwan
| | - Yung-Kuo Lin
- Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, 111 Hsin-Lung Road, Sec. 3, Taipei, 116, Taiwan.,Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Shih-Ann Chen
- Heart Rhythm Center and Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Yi-Jen Chen
- Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, 111 Hsin-Lung Road, Sec. 3, Taipei, 116, Taiwan. .,Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan. .,Cardiovascular Research Center, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan.
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12
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Chan CS, Lin YK, Chen YC, Lu YY, Chen SA, Chen YJ. Heart Failure Differentially Modulates Natural (Sinoatrial Node) and Ectopic (Pulmonary Veins) Pacemakers: Mechanism and Therapeutic Implication for Atrial Fibrillation. Int J Mol Sci 2019; 20:E3224. [PMID: 31262061 PMCID: PMC6651382 DOI: 10.3390/ijms20133224] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 06/28/2019] [Accepted: 06/28/2019] [Indexed: 12/14/2022] Open
Abstract
Heart failure (HF) frequently coexists with atrial fibrillation (AF) and dysfunction of the sinoatrial node (SAN), the natural pacemaker. HF is associated with chronic adrenergic stimulation, neurohormonal activation, abnormal intracellular calcium handling, elevated cardiac filling pressure and atrial stretch, and fibrosis. Pulmonary veins (PVs), which are the points of onset of ectopic electrical activity, are the most crucial AF triggers. A crosstalk between the SAN and PVs determines PV arrhythmogenesis. HF has different effects on SAN and PV electrophysiological characteristics, which critically modulate the development of AF and sick sinus syndrome. This review provides updates to improve our current understanding of the effects of HF in the electrical activity of the SAN and PVs as well as therapeutic implications for AF.
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Affiliation(s)
- Chao-Shun Chan
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei 11042, Taiwan
- Division of Cardiology, Department of Internal Medicine, Taipei Medical University Hospital, Taipei 11042, Taiwan
| | - Yung-Kuo Lin
- Division of Cardiology, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei 11042, Taiwan
- Division of Cardiovascular Medicine, Department of Internal Medicine, Wan-Fang Hospital, Taipei Medical University, Taipei 11696, Taiwan
| | - Yao-Chang Chen
- Department of Biomedical Engineering, National Defense Medical Center, Taipei 11490, Taiwan
| | - Yen-Yu Lu
- Division of Cardiology, Department of Internal Medicine, Sijhih Cathay General Hospital, New Taipei City 22174, Taiwan
- School of Medicine, College of Medicine, Fu-Jen Catholic University, New Taipei City 24257, Taiwan
| | - Shih-Ann Chen
- Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei 11217, Taiwan
- Institute of Clinical Medicine, and Cardiovascular Research Center, National Yang-Ming University, Taipei 11221, Taiwan
| | - Yi-Jen Chen
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei 11042, Taiwan.
- Division of Cardiovascular Medicine, Department of Internal Medicine, Wan-Fang Hospital, Taipei Medical University, Taipei 11696, Taiwan.
- Cardiovascular Research Center, Wan-Fang Hospital, Taipei Medical University, Taipei 11696, Taiwan.
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13
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Katsi V, Skalis G, Kallistratos MS, Tsioufis K, Makris T, Manolis AJ, Tousoulis D. Ivabradine and metoprolol in fixed dose combination: When, why and how to use it. Pharmacol Res 2019; 146:104279. [PMID: 31108185 DOI: 10.1016/j.phrs.2019.104279] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 04/01/2019] [Accepted: 05/16/2019] [Indexed: 11/30/2022]
Abstract
Heart rate is an important factor in coronary artery disease and its manifestations, and as such has been considered as a possible target for therapy. Although in epidemiological, and in less degree, in clinical studies derived indications of a possible pathogenetic role of heart rate in major cardiac diseases, clinical trials did not provided any strong evidence. However, even as a simple risk marker, remains important in the treatment of coronary artery disease and heart failure. Beta-blockers are the drugs most frequently used for heart rate control. However, recent studies constantly find insufficient effectiveness of beta-blockers in heart rate control and go further to question their efficacy on outcomes, making clear the need for an additional therapy. Ivabradine, a pure heart rate inhibitor, added to classic beta-blocker treatment represent the new therapeutic option in stable coronary disease and heart failure.
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Affiliation(s)
- V Katsi
- Cardiology Department, Hippokration Hospital, Athens, Greece
| | - G Skalis
- Department of Cardiology, Helena Venizelou Hospital, Athens, Greece
| | - M S Kallistratos
- Department of Cardiology, Asklepeion General Hospital, Athens, Greece.
| | - K Tsioufis
- Cardiology Department, Hippokration Hospital, Athens, Greece
| | - T Makris
- Department of Cardiology, Helena Venizelou Hospital, Athens, Greece
| | - A J Manolis
- Department of Cardiology, Asklepeion General Hospital, Athens, Greece
| | - D Tousoulis
- Department of Cardiology, Asklepeion General Hospital, Athens, Greece
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14
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Heart Failure Differentially Modulates the Effects of Ivabradine on the Electrical Activity of the Sinoatrial Node and Pulmonary Veins. J Card Fail 2018; 24:763-772. [DOI: 10.1016/j.cardfail.2018.09.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 07/15/2018] [Accepted: 09/27/2018] [Indexed: 11/19/2022]
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15
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Thiyagarajah A, Lau DH, Sanders P. Atrial fibrillation and conduction system disease: the roles of catheter ablation and permanent pacing. J Interv Card Electrophysiol 2018; 52:395-402. [PMID: 30074119 DOI: 10.1007/s10840-018-0429-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2018] [Accepted: 07/24/2018] [Indexed: 11/24/2022]
Abstract
Atrial fibrillation (AF) and diseases of the cardiac conduction system frequently co-exist, and interactions between these rhythm disturbances can adversely impact patient outcomes. Concurrent AF and sinus node disease often manifests as the tachy-brady syndrome wherein the underlying sinus node dysfunction can pose a challenge to AF management. Similarly, the combination of AF and left bundle branch block increases mortality in individuals with co-existent heart failure and hampers effective delivery of cardiac resynchronization therapy. A thorough understanding of the therapeutic interventions available for these conditions, including the role of catheter ablation and permanent pacemaker programming, is crucial for optimal management in affected patients.
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Affiliation(s)
- Anand Thiyagarajah
- Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute, University of Adelaide and Royal Adelaide Hospital, Adelaide, Australia
| | - Dennis H Lau
- Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute, University of Adelaide and Royal Adelaide Hospital, Adelaide, Australia
| | - Prashanthan Sanders
- Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute, University of Adelaide and Royal Adelaide Hospital, Adelaide, Australia.
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16
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Wu J, Fan X, Yang H, Yan L, Xu X, Duan H, Wang S, Chu Y. Usefulness of a Low Resting Heart Rate to Predict Recurrence of Atrial Fibrillation After Catheter Ablation in People ≥65 Years of Age. Am J Cardiol 2018; 122:97-101. [PMID: 29685573 DOI: 10.1016/j.amjcard.2018.03.025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2018] [Revised: 03/12/2018] [Accepted: 03/16/2018] [Indexed: 10/17/2022]
Abstract
A low resting heart rate (RHR) is associated with an increased risk of atrial fibrillation (AF), and this is common in older people. Whether a low RHR in older people can predict recurrence of AF after catheter ablation is unclear. A total of 329 consecutive patients ≥65 years of age with paroxysmal AF who underwent index circumferential pulmonary vein isolation were prospectively enrolled. A 10-second standard resting 12-lead electrocardiogram in sinus rhythm was recorded to measure the RR interval, P-wave duration, and PR interval. The RHR was calculated based on the mean RR interval. During a mean follow-up period of 17.0 ± 8.3 months (range, 3 to 32 months), 96 (29.2%) patients developed recurrence of AF. The AF recurrence rate was 46.2%, 32.3%, and 25.4% in patients with an RHR <50, 50 to 59, and ≥60 beats/min, respectively (log-rank test, p = 0.009). Cox regression analysis with adjustment for P-wave duration and the CHADS2 score showed that an RHR <50 beats/min (hazard ratio [HR] 1.92, 95% confidence interval [CI] 1.12 to 3.28, p = 0.017), advanced interatrial block (HR 1.82, 95% CI 1.09 to 3.04, p = 0.022), and left atrial diameter (HR 1.05, 95% CI 1.00 to 1.09, p = 0.029) were independent predictors of recurrence of AF after catheter ablation. In conclusion, in people ≥65 years of age, an RHR <50 beats/min is an independent predictor of AF recurrence in patients who have undergone catheter ablation for paroxysmal AF.
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17
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Liu CM, Lin CY, Chang SL, Lin YJ, Lo LW, Hu YF, Chao TF, Chung FP, Tuan TC, Liao JN, Chen YY, Te ALD, Yamada S, Kuo L, Li HY, Chang TY, Minh HQ, Salim S, Ba VV, Vicera JJB, Wu CI, Chuang CM, Huang TC, Hsieh YC, Chen SA. Intermediate Pause at Daytime Is Associated With Increased Cardiovascular Risk and Mortality: An 8-Year Cohort Study. J Am Heart Assoc 2018; 7:e009034. [PMID: 29895588 PMCID: PMC6220557 DOI: 10.1161/jaha.118.009034] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 05/15/2018] [Indexed: 11/16/2022]
Abstract
BACKGROUND Long-term cardiovascular risk in patients with intermediate pauses remains unclear. Whether asymptomatic patients with intermediate pauses have increased future cardiovascular events remains unknown. We hypothesize that intermediate pause is associated with increased cardiovascular risk and mortality. METHODS AND RESULTS We retrospectively analyzed 5291 patients who have pauses of <3 seconds on 24-hour Holter monitoring. Patients with pauses of 2 to 3 seconds constitute the intermediate pause patients, who are further divided into daytime pause (8:00 am-8:00 pm), nighttime pause (8:00 pm-8:00 am), and daytime plus nighttime pause groups depending on the occurring time of the pauses. The rest of the patients (pause <2 seconds) are the no pause group. The multivariate Cox hazards regression model was used to assess the hazard ratio for mortality (primary outcome) and adverse cardiovascular events (secondary outcome). There were 4859 (91.8%) patients in no pause, 248 (4.7%) in nighttime pause, 103 (1.9%) in daytime pause, and 81 (1.5%) in daytime plus nighttime pause groups. After a follow-up of 8.8±1.7 years' follow-up, 343 (6.5%) patients died. The risk for adverse cardiovascular events, including all-cause hospitalization, cardiovascular-cause hospitalization, pacemaker implantation, new-onset atrial fibrillation/heart failure, and transient ischemic attack, were higher in daytime pause and nighttime pause patients than those in the no pause group. Daytime pause (hazard ratio, 2.35; P=0.008) and daytime plus nighttime pause (hazard ratio, 2.26; P=0.016) patients have a higher mortality rate than that in nighttime pause. CONCLUSIONS Patients with intermediate pause are associated with increased cardiovascular risk. Intermediate pauses occurring at daytime have a higher mortality rate than that at nighttime during long-term follow-up.
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Affiliation(s)
- Chih-Min Liu
- Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Chin-Yu Lin
- Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
- Institute of Clinical Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan
- Department of Internal Medicine, Yuan-Shan Branch, Taipei Veterans General Hospital, Yilan, Taiwan
| | - Shih-Lin Chang
- Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
- Institute of Clinical Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan
| | - Yenn-Jiang Lin
- Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
- Institute of Clinical Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan
| | - Li-Wei Lo
- Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
- Institute of Clinical Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan
| | - Yu-Feng Hu
- Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
- Institute of Clinical Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan
| | - Tze-Fan Chao
- Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
- Institute of Clinical Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan
| | - Fa-Po Chung
- Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
- Institute of Clinical Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan
| | - Ta-Chuan Tuan
- Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
- Institute of Clinical Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan
| | - Jo-Nan Liao
- Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
- Institute of Clinical Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan
| | - Yun-Yu Chen
- Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
- Institute of Epidemiology and Preventive Medicine, College of Public Health National Taiwan University, Taipei, Taiwan
| | - Abigail Louise D Te
- Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Shinya Yamada
- Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Ling Kuo
- Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
- Institute of Clinical Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan
| | - Hsing-Yuan Li
- Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Ting-Yung Chang
- Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
- Institute of Clinical Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan
| | - Hoang Quang Minh
- Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Simon Salim
- Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Vu Van Ba
- Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Jennifer Jeanne B Vicera
- Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Cheng-I Wu
- Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
- Institute of Clinical Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan
| | - Chieh-Mao Chuang
- Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Ting-Chung Huang
- Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Yu-Cheng Hsieh
- Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
- Institute of Clinical Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan
- Cardiovascular Center, Taichung Veterans General Hospital, Taichung, Taiwan
- Department of Internal Medicine, Chiayi Branch, Taichung Veterans General Hospital, Taichung, Taiwan
| | - Shih-Ann Chen
- Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
- Institute of Clinical Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan
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18
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Lin YK, Chen YC, Chen YA, Huang JH, Chen SA, Chen YJ. Levosimendan differentially modulates electrophysiological activities of sinoatrial nodes, pulmonary veins, and the left and right atria. J Cardiovasc Electrophysiol 2018; 29:1150-1158. [DOI: 10.1111/jce.13629] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 05/01/2018] [Accepted: 05/02/2018] [Indexed: 11/29/2022]
Affiliation(s)
- Yung-Kuo Lin
- Division of Cardiovascular Medicine, Department of Internal Medicine; Wan Fang Hospital, Taipei Medical University; Taipei Taiwan
- Division of Cardiology, Department of Internal Medicine, School of Medicine, College of Medicine; Taipei Medical University; Taipei Taiwan
| | - Yao-Chang Chen
- Department of Biomedical Engineering; National Defense Medical Center; Taipei Taiwan
| | - Yi-Ann Chen
- Division of Nephrology; Sijhih Cathay General Hospital; New Taipei City Taiwan
| | - Jen-Hung Huang
- Division of Cardiovascular Medicine, Department of Internal Medicine; Wan Fang Hospital, Taipei Medical University; Taipei Taiwan
- Division of Cardiology, Department of Internal Medicine, School of Medicine, College of Medicine; Taipei Medical University; Taipei Taiwan
| | - Shih-Ann Chen
- Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, and Institute of Clinical Medicine and Cardiovascular Research Center; National Yang-Ming University; Taipei Taiwan
| | - Yi-Jen Chen
- Division of Cardiovascular Medicine, Department of Internal Medicine; Wan Fang Hospital, Taipei Medical University; Taipei Taiwan
- Graduate Institute of Clinical Medicine, College of Medicine; Taipei Medical University; Taipei Taiwan
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19
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Chan CS, Lin YK, Kao YH, Chen YC, Chen SA, Chen YJ. Hydrogen sulphide increases pulmonary veins and atrial arrhythmogenesis with activation of protein kinase C. J Cell Mol Med 2018; 22:3503-3513. [PMID: 29659148 PMCID: PMC6010708 DOI: 10.1111/jcmm.13627] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 03/09/2018] [Indexed: 12/29/2022] Open
Abstract
Hydrogen sulphide (H2 S), one of the most common toxic air pollutants, is an important aetiology of atrial fibrillation (AF). Pulmonary veins (PVs) and left atrium (LA) are the most important AF trigger and substrate. We investigated whether H2 S may modulate the arrhythmogenesis of PVs and atria. Conventional microelectrodes and whole-cell patch clamp were performed in rabbit PV, sinoatrial node (SAN) or atrial cardiomyocytes before and after the perfusion of NaHS with or without chelerythrine (a selective PKC inhibitor), rottlerin (a specific PKC δ inhibitor) or KB-R7943 (a NCX inhibitor). NaHS reduced spontaneous beating rates, but increased the occurrences of delayed afterdepolarizations and burst firing in PVs and SANs. NaHS (100 μmol/L) increased IKATP and INCX in PV and LA cardiomyocytes, which were attenuated by chelerythrine (3 μmol/L). Chelerythrine, rottlerin (10 μmol/L) or KB-R7943 (10 μmol/L) attenuated the arrhythmogenic effects of NaHS on PVs or SANs. NaHS shortened the action potential duration in LA, but not in right atrium or in the presence of chelerythrine. NaHS increased PKC activity, but did not translocate PKC isoforms α, ε to membrane in LA. In conclusion, through protein kinase C signalling, H2 S increases PV and atrial arrhythmogenesis, which may contribute to air pollution-induced AF.
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Affiliation(s)
- Chao-Shun Chan
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.,Division of Cardiology, Department of Internal Medicine, Taipei Medical University Hospital, Taipei, Taiwan
| | - Yung-Kuo Lin
- Division of Cardiology, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.,Division of Cardiovascular Medicine, Department of Internal Medicine, Wang Fang Hospital, Taipei Medical University, Taipei, Taiwan
| | - Yu-Hsun Kao
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.,Department of Medical Education and Research, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
| | - Yao-Chang Chen
- Department of Biomedical Engineering, National Defense Medical Center, Taipei, Taiwan
| | - Shih-Ann Chen
- Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, and Institute of Clinical Medicine and Cardiovascular Research Center, National Yang-Ming University, Taipei, Taiwan
| | - Yi-Jen Chen
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.,Division of Cardiovascular Medicine, Department of Internal Medicine, Wang Fang Hospital, Taipei Medical University, Taipei, Taiwan
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20
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Li N, Wang ZS, Wang XH, Xu YJ, Qiao Q, Li XM, Di RM, Guo XJ, Li RG, Zhang M, Qiu XB, Yang YQ. A SHOX2 loss-of-function mutation underlying familial atrial fibrillation. Int J Med Sci 2018; 15:1564-1572. [PMID: 30443179 PMCID: PMC6216059 DOI: 10.7150/ijms.27424] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 08/29/2018] [Indexed: 01/01/2023] Open
Abstract
Atrial fibrillation (AF), as the most common sustained cardiac arrhythmia, is associated with substantially increased morbidity and mortality. Aggregating evidence demonstrates that genetic defects play a crucial role in the pathogenesis of AF, especially in familial AF. Nevertheless, AF is of pronounced genetic heterogeneity, and in an overwhelming majority of cases the genetic determinants underlying AF remain elusive. In the current study, 162 unrelated patients with familial AF and 238 unrelated healthy individuals served as controls were recruited. The coding exons and splicing junction sites of the SHOX2 gene, which encodes a homeobox-containing transcription factor essential for proper development and function of the cardiac conduction system, were sequenced in all study participants. The functional effect of the mutant SHOX2 protein was characterized with a dual-luciferase reporter assay system. As a result, a novel heterozygous SHOX2 mutation, c.580C>T or p.R194X, was identified in an index patient, which was absent from the 476 control chromosomes. Genetic analysis of the proband's pedigree revealed that the nonsense mutation co-segregated with AF in the family with complete penetrance. Functional assays demonstrated that the mutant SHOX2 protein had no transcriptional activity compared with its wild-type counterpart. In conclusion, this is the first report on the association of SHOX2 loss-of-function mutation with enhanced susceptibility to familial AF, which provides novel insight into the molecular mechanism underpinning AF, suggesting potential implications for genetic counseling and individualized management of AF patients.
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Affiliation(s)
- Ning Li
- Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiao Tong University, 241 West Huaihai Road, Shanghai 200030, China
| | - Zhang-Sheng Wang
- Department of Cardiology, The Fifth People's Hospital of Shanghai, Fudan University, 801 Heqing Road, Shanghai 200240, China
| | - Xin-Hua Wang
- Department of Cardiology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, 1630 Dongfang Road, Shanghai 200127, China
| | - Ying-Jia Xu
- Department of Cardiology, The Fifth People's Hospital of Shanghai, Fudan University, 801 Heqing Road, Shanghai 200240, China
| | - Qi Qiao
- Department of Cardiology, The Fifth People's Hospital of Shanghai, Fudan University, 801 Heqing Road, Shanghai 200240, China
| | - Xiu-Mei Li
- Department of Cardiology, The Fifth People's Hospital of Shanghai, Fudan University, 801 Heqing Road, Shanghai 200240, China
| | - Ruo-Min Di
- Department of Cardiology, The Fifth People's Hospital of Shanghai, Fudan University, 801 Heqing Road, Shanghai 200240, China
| | - Xiao-Juan Guo
- Department of Cardiology, The Fifth People's Hospital of Shanghai, Fudan University, 801 Heqing Road, Shanghai 200240, China.,Department of Cardiovascular Research Laboratory, The Fifth People's Hospital of Shanghai, Fudan University, 801 Heqing Road, Shanghai 200240, China
| | - Ruo-Gu Li
- Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiao Tong University, 241 West Huaihai Road, Shanghai 200030, China
| | - Min Zhang
- Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiao Tong University, 241 West Huaihai Road, Shanghai 200030, China
| | - Xing-Biao Qiu
- Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiao Tong University, 241 West Huaihai Road, Shanghai 200030, China
| | - Yi-Qing Yang
- Department of Cardiology, The Fifth People's Hospital of Shanghai, Fudan University, 801 Heqing Road, Shanghai 200240, China.,Department of Cardiovascular Research Laboratory, The Fifth People's Hospital of Shanghai, Fudan University, 801 Heqing Road, Shanghai 200240, China.,Department of Central Laboratory, The Fifth People's Hospital of Shanghai, Fudan University, 801 Heqing Road, Shanghai 200240, China
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21
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Lin YK, Chen YA, Lee TI, Chen YC, Chen SA, Chen YJ. Aging Modulates the Substrate and Triggers Remodeling in Atrial Fibrillation. Circ J 2017; 82:1237-1244. [PMID: 28904308 DOI: 10.1253/circj.cj-17-0242] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Aging plays a critical role in the genesis of atrial fibrillation (AF) and also increases the risks of cardiac dysfunction and stroke in AF patients. AF is caused by increased AF triggering from abnormalities of the thoracic vein and/or modulated substrate (atrial) with enhancement of AF maintenance. Clinical and laboratory evidence indicates that aging is significant in the creation of atrial electrical and structural remodeling that leads to increased susceptibility to AF occurrence. Aging is commonly associated with cardiovascular comorbidities, oxidative stress, calcium dysregulation, atrial myopathy with apoptosis, and fibrosis, which all contribute to the genesis of AF. This review updates the current understanding of the effects of aging on the pathophysiology of AF.
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Affiliation(s)
- Yung-Kuo Lin
- Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University.,Division of Cardiology, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University
| | - Yi-Ann Chen
- Division of Nephrology, Sijhih Cathay General Hospital
| | - Ting-I Lee
- Division of Endocrinology and Metabolism, Wan Fang Hospital, Taipei Medical University
| | - Yao-Chang Chen
- Department of Biomedical Engineering, National Defense Medical Center
| | - Shih-Ann Chen
- Division of Cardiology and Cardiovascular Research Center, Veterans General Hospital-Taipei
| | - Yi-Jen Chen
- Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University.,Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University
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22
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Lin YK, Cheng CC, Tsai MC, Wu PY, Chen YA, Chen YC, Chen SA, Chen YJ. Mitochondrial dysfunction on sinoatrial node and pulmonary vein electrophysiological activities. Exp Ther Med 2017; 13:2486-2492. [PMID: 28565869 DOI: 10.3892/etm.2017.4285] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2016] [Accepted: 01/13/2017] [Indexed: 11/06/2022] Open
Abstract
Atrial fibrillation (AF) is associated with mitochondrial dysfunction. Sinoatrial node (SAN) dysfunction increases arrhythmogenesis of pulmonary veins (PVs), which is the most important trigger of AF; however, it is not clear whether mitochondrial dysfunction differentially regulates electrical activity of SANs and PVs. In the present study, conventional microelectrodes were used to record the action potentials (APs) in isolated rabbit PVs, SANs, left atrium (LA) and right atrium (RA) before and after application of trifluorocarbonylcyanide phenylhydrazone (FCCP; a mitochondrial uncoupling agent) at 10, 100 and 300 nM. FCCP application at 100 and 300 nM decreased spontaneous rates in PVs and in SANs at 10, 100 and 300 nM. FCCP shortened the 20, 50 and 90% AP durations in the LA, and shortened only the 20% AP duration in the RA. FCCP caused a greater rate reduction in SANs than in PVs; however, in the presence of coenzyme-Q10 (10 µM), FCCP reduced the beating rate in PVs and SANs to a similar extent. In SAN-PV preparations with intact electrical connections, FCCP (100 nM) application shifted the SAN-PV electrical conduction into PV-SAN conduction in 5 (62.5%) of 8 preparations. In conclusion, mitochondrial dysfunction modulates PV and SAN electrical activities, which may contribute to atrial arrhythmogenesis.
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Affiliation(s)
- Yung-Kuo Lin
- Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei 110, Taiwan, R.O.C.,School of Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan, R.O.C
| | - Chen-Chuan Cheng
- Division of Cardiology, Chi-Mei Medical Center, Tainan 710, Taiwan, R.O.C.,Department of Internal Medicine, Chung Shan Medical University, Taichung 402, Taiwan, R.O.C
| | - Min-Chien Tsai
- Department of Biomedical Engineering and Graduate Institute of Physiology, National Defense Medical Center, Taipei 114, Taiwan, R.O.C
| | - Pei-Yu Wu
- Department of Biomedical Engineering and Graduate Institute of Physiology, National Defense Medical Center, Taipei 114, Taiwan, R.O.C
| | - Yi-Ann Chen
- Division of Nephrology, Sijhih Cathay General Hospital, New Taipei 221, Taiwan, R.O.C
| | - Yao-Chang Chen
- Department of Biomedical Engineering and Graduate Institute of Physiology, National Defense Medical Center, Taipei 114, Taiwan, R.O.C
| | - Shih-Ann Chen
- Division of Cardiology and Cardiovascular Research Center, Taipei Veterans General Hospitals, National Yang-Ming University School of Medicine, Taipei 112, Taiwan, R.O.C
| | - Yi-Jen Chen
- Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei 110, Taiwan, R.O.C.,Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan, R.O.C
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23
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Weirich J. [Remodeling of the aging heart : Sinus node dysfunction and atrial fibrillation]. Herzschrittmacherther Elektrophysiol 2017; 28:29-38. [PMID: 28204916 DOI: 10.1007/s00399-017-0485-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 01/12/2017] [Indexed: 12/19/2022]
Abstract
The incidence of both sinus node dysfunction (SND) and atrial fibrillation (AF) increases with age. SND and AF frequently coexist. Likewise, they are often associated with cardiovascular diseases. Both arrhythmias share similar pathomechanisms such as structural and functional remodeling, i. e., degenerative fibrosis and altered Ca2+ handling, respectively. A growing body of evidence suggests an important role for the CamKII (Ca2+/calmodulin-dependent protein kinase II) in structural as well as in functional remodeling. In the sinus node, remodeling leads to degenerative fibrosis and as a consequence to sinus node arrest or to reentry (brady/tachycardia). In the atrium, remodeling sets the conditions for reentry and its triggering mechanisms, especially the conditions for triggered activity on the basis of delayed afterdepolarizations (DAD). Thus, SND and AF seem to be different phenotypes of related pathophysiological mechanisms. On the other hand, it remains controversial as to whether SND causes AF or vice versa.
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Affiliation(s)
- Jörg Weirich
- Institut für Physiologie, Abteilung II, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Str. 7, 79104, Freiburg, Deutschland.
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24
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Abstract
Although sinus node dysfunction (SND) and atrial arrhythmias frequently coexist and interact, the putative mechanism linking the 2 remain unclear. Although SND is accompanied by atrial myocardial structural changes in the right atrium, atrial fibrillation (AF) is a disease of variable interactions between left atrial triggers and substrate most commonly of left atrial origin. Significant advances have been made in our understanding of the genetic and pathophysiologic mechanism underlying the development and progression of SND and AF. Although some patients manifest SND as a result of electric remodeling induced by periods of AF, others develop progressive atrial structural remodeling that gives rise to both conditions together. The treatment strategy will thus vary according to the predominant disease phenotype. Although catheter ablation will benefit patients with predominantly AF and secondary SND, cardiac pacing may be the mainstay of therapy for patients with predominant fibrotic atrial cardiomyopathy. This contemporary review summarizes current knowledge on sinus node pathophysiology with the broader goal of yielding insights into the complex relationship between sinus node disease and atrial arrhythmias.
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Affiliation(s)
- Roy M John
- From Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA.
| | - Saurabh Kumar
- From Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
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25
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Gap junction modifiers regulate electrical activities of the sinoatrial node and pulmonary vein: Therapeutic implications in atrial arrhythmogenesis. Int J Cardiol 2016; 221:529-36. [PMID: 27414735 DOI: 10.1016/j.ijcard.2016.07.027] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 07/04/2016] [Indexed: 11/22/2022]
Abstract
BACKGROUND Gap junction (GJ) dysfunctions predispose cardiac tissues to various arrhythmias. Sinoatrial node (SAN) and pulmonary veins (PVs) are closely related atrial dysrhythmia. This study evaluated whether GJ modifications modulate SAN and PVs electrical activities. METHODS Conventional microelectrodes were used to record action potentials in isolated rabbit SAN, PVs, and connected PV-SAN tissue preparations before and after heptanol (GJ inhibitor) and PQ1 (GJ enhancer) administration with and without isoproterenol. A whole-cell patch clamp was used to record the electrical activities before and after heptanol in single SAN and PV cardiomyocytes. RESULTS Heptanol (1, 3, and 10μM) reduced the spontaneous beating rates of isolated SAN preparations but not PVs. Heptanol (10μM) decelerated the SAN leading rhythm in the PV-SAN preparations and induced PV burst firings without (3 of 6, 50%) and with (6 of 6, 100%) isoproterenol (1μM). Heptanol (10μM) also reduced the spontaneous beating rates in single SAN cardiomyocyte, but not PV cardiomyocyte, with a decreased pacemaker current. PQ1 (50 and 500nM) treatment did not change the spontaneous beating rates in isolated SAN and PV preparations. In the connected PV-SAN preparations, PQ1 (500nM) did not induce any PV firing even having additional isoproterenol treatment (1μM). Moreover, PQ1 (500nM) prevented heptanol-induced electrical changes in SAN and PVs preparations. CONCLUSION GJ dysfunction modulates SAN and PV electrical activity, which may contribute to atrial arrhythmogenesis. GJ enhancer has a therapeutic potential in SAN dysfunction and atrial arrhythmogenesis.
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26
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Hoffmann S, Clauss S, Berger IM, Weiß B, Montalbano A, Röth R, Bucher M, Klier I, Wakili R, Seitz H, Schulze-Bahr E, Katus HA, Flachsbart F, Nebel A, Guenther SP, Bagaev E, Rottbauer W, Kääb S, Just S, Rappold GA. Coding and non-coding variants in the SHOX2 gene in patients with early-onset atrial fibrillation. Basic Res Cardiol 2016; 111:36. [PMID: 27138930 PMCID: PMC4853439 DOI: 10.1007/s00395-016-0557-2] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 04/18/2016] [Indexed: 11/25/2022]
Abstract
Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia with a strong genetic component. Molecular pathways involving the homeodomain transcription factor Shox2 control the development and function of the cardiac conduction system in mouse and zebrafish. Here we report the analysis of human SHOX2 as a potential susceptibility gene for early-onset AF. To identify causal variants and define the underlying mechanisms, results from 378 patients with early-onset AF before the age of 60 years were analyzed and compared to 1870 controls or reference datasets. We identified two missense mutations (p.G81E, p.H283Q), that were predicted as damaging. Transactivation studies using SHOX2 targets and phenotypic rescue experiments in zebrafish demonstrated that the p.H283Q mutation severely affects SHOX2 pacemaker function. We also demonstrate an association between a 3'UTR variant c.*28T>C of SHOX2 and AF (p = 0.00515). Patients carrying this variant present significantly longer PR intervals. Mechanistically, this variant creates a functional binding site for hsa-miR-92b-5p. Circulating hsa-miR-92b-5p plasma levels were significantly altered in AF patients carrying the 3'UTR variant (p = 0.0095). Finally, we demonstrate significantly reduced SHOX2 expression levels in right atrial appendages of AF patients compared to patients with sinus rhythm. Together, these results suggest a genetic contribution of SHOX2 in early-onset AF.
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Affiliation(s)
- Sandra Hoffmann
- Department of Human Molecular Genetics, Institute of Human Genetics, University Heidelberg, INF 366, 69120, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), Partner site Heidelberg/Mannheim, Heidelberg, Germany
| | - Sebastian Clauss
- Department of Medicine I, University Hospital Munich, Ludwig-Maximilians-University Munich (LMU), Munich, Germany.,DZHK (German Centre for Cardiovascular Research), Partner site Munich, Munich, Germany
| | - Ina M Berger
- Department of Internal Medicine II, University of Ulm, Ulm, Germany
| | - Birgit Weiß
- Department of Human Molecular Genetics, Institute of Human Genetics, University Heidelberg, INF 366, 69120, Heidelberg, Germany
| | - Antonino Montalbano
- Department of Human Molecular Genetics, Institute of Human Genetics, University Heidelberg, INF 366, 69120, Heidelberg, Germany
| | - Ralph Röth
- Department of Human Molecular Genetics, Institute of Human Genetics, University Heidelberg, INF 366, 69120, Heidelberg, Germany
| | - Madeline Bucher
- Department of Human Molecular Genetics, Institute of Human Genetics, University Heidelberg, INF 366, 69120, Heidelberg, Germany
| | - Ina Klier
- Department of Medicine I, University Hospital Munich, Ludwig-Maximilians-University Munich (LMU), Munich, Germany
| | - Reza Wakili
- Department of Medicine I, University Hospital Munich, Ludwig-Maximilians-University Munich (LMU), Munich, Germany.,DZHK (German Centre for Cardiovascular Research), Partner site Munich, Munich, Germany
| | - Hervé Seitz
- Institut de génétique humaine (CNRS UPR 1142), Montpellier, France
| | - Eric Schulze-Bahr
- Department of Cardiovascular Medicine, Institute for Genetics of Heart Diseases, University Hospital Münster, Münster, Germany
| | - Hugo A Katus
- DZHK (German Centre for Cardiovascular Research), Partner site Heidelberg/Mannheim, Heidelberg, Germany.,Department of Internal Medicine III, University Hospital Heidelberg, Heidelberg, Germany
| | | | - Almut Nebel
- Institute of Clinical Molecular Biology, University of Kiel, Kiel, Germany
| | - Sabina Pw Guenther
- Department of Cardiac Surgery, University Hospital Munich, Ludwig-Maximilians-University Munich (LMU), Munich, Germany
| | - Erik Bagaev
- Department of Cardiac Surgery, University Hospital Munich, Ludwig-Maximilians-University Munich (LMU), Munich, Germany
| | | | - Stefan Kääb
- Department of Medicine I, University Hospital Munich, Ludwig-Maximilians-University Munich (LMU), Munich, Germany.,DZHK (German Centre for Cardiovascular Research), Partner site Munich, Munich, Germany
| | - Steffen Just
- Department of Internal Medicine II, University of Ulm, Ulm, Germany
| | - Gudrun A Rappold
- Department of Human Molecular Genetics, Institute of Human Genetics, University Heidelberg, INF 366, 69120, Heidelberg, Germany. .,DZHK (German Centre for Cardiovascular Research), Partner site Heidelberg/Mannheim, Heidelberg, Germany.
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27
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Zylla MM, Brachmann J, Lewalter T, Hoffmann E, Kuck KH, Andresen D, Willems S, Hochadel M, Senges J, Katus HA, Thomas D. Catheter ablation of atrial fibrillation in patients with concomitant sinus bradycardia-Insights from the German Ablation Registry. J Electrocardiol 2016; 49:117-23. [PMID: 26806120 DOI: 10.1016/j.jelectrocard.2015.12.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2015] [Indexed: 10/22/2022]
Abstract
AIMS This investigation addresses procedural characteristics of catheter ablation in patients with atrial fibrillation (AF) and sinus bradycardia. METHODS From the prospective, multi-center German Ablation Registry 1073 patients with sinus rhythm at the time of AF ablation were divided into two groups according to heart rate at start of procedure (A, <60 beats per minute (bpm), n=197; B, 60-99bpm, n=876). RESULTS Acute procedural success was high (≥98%) and similar between groups. Procedure duration and energy application time were increased in group A (180min vs. 155min and 2561s vs. 1879s, respectively). Major complications were more frequent in group A (2.2% vs. 0.5%), and a greater proportion of these patients was discharged under antiarrhythmic medication (64% vs. 52%). CONCLUSION Catheter ablation of AF with concomitant sinus bradycardia is associated with high procedural efficacy, longer procedure- and energy application durations, and a slightly elevated complication rate.
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Affiliation(s)
- Maura M Zylla
- Department of Cardiology, Medical University Hospital, Im Neuenheimer Feld 410, Heidelberg, Germany
| | - Johannes Brachmann
- Department of Cardiology, Hospital Coburg, Ketschendorfer Str. 33, Coburg, Germany
| | | | - Ellen Hoffmann
- Department of Cardiology/Intensive Care Medicine, Heart Center Munich-Bogenhausen, Englschalkinger Str. 77, Munich, Germany
| | - Karl-Heinz Kuck
- Department of Cardiology, Asklepios Hospital St. Georg, Lohmühlenstraße 5, Hamburg, Germany
| | - Dietrich Andresen
- Department of Cardiology, Vivantes Hospital, Klinikum am Urban, Dieffenbachstraße 1, Berlin, Germany
| | - Stephan Willems
- University Heart Center, Department of Cardiology/Electrophysiology, Martinistraße 52, Hamburg, Germany
| | - Matthias Hochadel
- Stiftung Institut für Herzinfarktforschung, IHF, Bremserstraße 79, Ludwigshafen, Germany
| | - Jochen Senges
- Stiftung Institut für Herzinfarktforschung, IHF, Bremserstraße 79, Ludwigshafen, Germany
| | - Hugo A Katus
- Department of Cardiology, Medical University Hospital, Im Neuenheimer Feld 410, Heidelberg, Germany
| | - Dierk Thomas
- Department of Cardiology, Medical University Hospital, Im Neuenheimer Feld 410, Heidelberg, Germany.
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28
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Lu YY, Cheng CC, Chen YC, Lin YK, Chen SA, Chen YJ. Electrolyte disturbances differentially regulate sinoatrial node and pulmonary vein electrical activity: A contribution to hypokalemia- or hyponatremia-induced atrial fibrillation. Heart Rhythm 2015; 13:781-8. [PMID: 26654920 DOI: 10.1016/j.hrthm.2015.12.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Indexed: 02/08/2023]
Abstract
BACKGROUND Hypokalemia and hyponatremia increase the occurrence of atrial fibrillation. Sinoatrial nodes (SANs) and pulmonary veins (PVs) play a critical role in the pathophysiology of atrial fibrillation. OBJECTIVE The purpose of this study was to evaluate whether electrolyte disturbances with low concentrations of potassium ([K(+)]) or sodium ([Na(+)]) modulate SAN and PV electrical activity and arrhythmogenesis, and to investigate potential underlying mechanisms. METHODS Conventional microelectrodes were used to record electrical activity in rabbit SAN and PV tissue preparations before and after perfusion with different low [K(+)] or [Na(+)], interacting with the Na(+)-Ca(2+) exchanger inhibitor KB-R7943 (10 μΜ). RESULTS Low [K(+)] (3.5, 3, 2.5, and 2 mM) decreased beating rates in PV cardiomyocytes with genesis of delayed afterdepolarizations (DADs), burst firing, and increased diastolic tension. Low [K(+)] (3.5, 3, 2.5, and 2 mM) also decreased SAN beating rates, with genesis of DADs. Low [Na(+)] increased PV diastolic tension, DADs, and burst firing, which was attenuated in the co-superfusion with low [K(+)] (2 mM). In contrast, low [Na(+)] had little effect on SAN electrical activities. KB-R7943 (10 μΜ) reduced the occurrences of low [K(+)] (2 mM)- or low [Na(+)] (110 mM)-induced DAD and burst firing in both PVs and SANs. CONCLUSION Low [K(+)] and low [Na(+)] differentially modulate SAN and PV electrical properties. Low [K(+)]- or low [Na(+)]-induced slowing of SAN beating rate and genesis of PV burst firing may contribute to the high occurrence of atrial fibrillation during hypokalemia or hyponatremia.
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Affiliation(s)
- Yen-Yu Lu
- Division of Cardiology, Sijhih Cathay General Hospital, New Taipei City, Taiwan; School of Medicine, Fu-Jen Catholic University, New Taipei City, Taiwan
| | | | - Yao-Chang Chen
- Department of Biomedical Engineering, National Defense Medical Center, Taipei, Taiwan
| | - Yung-Kuo Lin
- Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan; Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Shih-Ann Chen
- National Yang-Ming University, School of Medicine; Division of Cardiology and Cardiovascular Research Center, Veterans General Hospital-Taipei, Taipei, Taiwan
| | - Yi-Jen Chen
- Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan; Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
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29
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Huang SY, Chen YC, Kao YH, Hsieh MH, Chen YA, Chen WP, Lin YK, Chen SA, Chen YJ. Renal failure induces atrial arrhythmogenesis from discrepant electrophysiological remodeling and calcium regulation in pulmonary veins, sinoatrial node, and atria. Int J Cardiol 2015; 202:846-57. [PMID: 26476981 DOI: 10.1016/j.ijcard.2015.10.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2015] [Revised: 09/17/2015] [Accepted: 10/03/2015] [Indexed: 01/03/2023]
Abstract
BACKGROUND Renal failure (RF) increases the risk of atrial fibrillation (AF), but arrhythmogenic mechanism is unclear. The present study investigated the electrophysiological effects of RF on AF trigger (pulmonary veins, PVs) and substrate (atria) and evaluated potential underlying mechanisms. METHODS Electrocardiographic, echocardiographic, and biochemical studies were conducted in rabbits with and without antibiotic-induced mild (creatinine=1.5-6.0 mg/dl) and advanced (creatinine>6.0 mg/dl) RF. Conventional microelectrode techniques, western blotting, and histological examinations were performed using the isolated rabbit PV, left atrium (LA), right atrium (RA) and sinoatrial node (SAN). RESULTS Advanced RF rabbits (n=18) had a higher incidence (33.3% vs. 11.1% and 0%, p<0.05) of atrial arrhythmia than mild RF (n=18) and control (n=18) rabbits. Advanced RF rabbits exhibited faster PV spontaneous activities, longer action potential duration (APD) in the LA, higher fibrosis in the LA, and slower SAN beating rates than control rabbits, but had a similar APD and fibrosis in the RA. Caffeine (1 mM) increased advanced RF PV arrhythmogenesis, which is blocked by flecainide (10 μM), or KB-R7943 (10 μM). Moreover, advanced RF rabbits had a higher expression of the Na+/Ca2+ exchanger, protein kinase A, phosphorylated ryanodine receptor (Serine 2808), and phosphorylated phospholamban (Serine 16) in PVs, and a higher expression of Cav 1.2 in the LA, and a lower expression of hyperpolarization-activated cyclic nucleotide-gated potassium channel 4 in the SAN. CONCLUSIONS Advanced RF increases atrial arrhythmia by modulating the distinctive electrophysiological characteristics of the PV, LA, and SAN.
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Affiliation(s)
- Shih-Yu Huang
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; Division of Cardiology, Department of Internal Medicine, Cathay General Hospital, Taipei, Taiwan
| | - Yao-Chang Chen
- Department of Biomedical Engineering, National Defense Medical Center, Taipei, Taiwan
| | - Yu-Hsun Kao
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; Department of Medical Education and Research, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
| | - Ming-Hsiung Hsieh
- Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
| | - Yi-Ann Chen
- Division of Nephrology, Department of Internal Medicine, Sijhih Cathay General Hospital, New Taipei City, Taiwan
| | - Wan-Ping Chen
- Department of Laboratory Medicine, Sijhih Cathay General Hospital, New Taipei City, Taiwan
| | - Yung-Kuo Lin
- Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
| | - Shih-Ann Chen
- School of Medicine, National Yang-Ming University, Division of Cardiology and Cardiovascular Research Center, Veterans General Hospital-Taipei, Taipei, Taiwan
| | - Yi-Jen Chen
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan.
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30
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Chronotropic Modulation of the Source-Sink Relationship of Sinoatrial-Atrial Impulse Conduction and Its Significance to Initiation of AF: A One-Dimensional Model Study. BIOMED RESEARCH INTERNATIONAL 2015; 2015:496418. [PMID: 26229960 PMCID: PMC4502286 DOI: 10.1155/2015/496418] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Revised: 02/25/2015] [Accepted: 03/10/2015] [Indexed: 01/15/2023]
Abstract
Initiation and maintenance of atrial fibrillation (AF) is often associated with pharmacologically or pathologically induced bradycardic states. Even drugs specifically developed in order to counteract cardiac arrhythmias often combine their action with bradycardia and, in turn, with development of AF, via still largely unknown mechanisms. This study aims to simulate action potential (AP) conduction between sinoatrial node (SAN) and atrial cells, either arranged in cell pairs or in a one-dimensional strand, where the relative amount of SAN membrane is made varying, in turn, with junctional resistance. The source-sink relationship between the two membrane types is studied in control conditions and under different simulated chronotropic interventions, in order to define a safety factor for pacemaker-to-atrial AP conduction (SASF) for each treatment. Whereas antiarrhythmic-like interventions which involve downregulation of calcium channels or of calcium handling decrease SASF, the simulation of Ivabradine administration does so to a lesser extent. Particularly interesting is the increase of SASF observed when downregulation G Kr, which simulates the administration of class III antiarrhythmic agents and is likely sustained by an increase in I CaL. Also, the increase in SASF is accompanied by a decreased conduction delay and a better entrainment of repolarization, which is significant to anti-AF strategies.
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Slow Heart Rate Predicts New Occurrence of Atrial Fibrillation. Heart Lung Circ 2015; 24:1087-93. [PMID: 26105987 DOI: 10.1016/j.hlc.2015.04.185] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Revised: 04/25/2015] [Accepted: 04/29/2015] [Indexed: 01/19/2023]
Abstract
BACKGROUND This study aims to investigate the relation between baseline heart rate and new occurrence of AF in patients with mild symptoms. METHODS Patients without pre-existing AF or structural heart disease who underwent 24-hour electrocardiogram (ECG) monitoring for palpitations, dizziness or syncope were followed up for new-onset AF. RESULTS 428 patients (mean age 66.6±10.2 years, 43.7% male) were classified according to the average heart rate into four quartiles (1(st) quartile: <63 beat per minute (bpm); 2(nd) quartile: 63-70 bpm; 3(rd) quartile 70-77 bpm; and 4(th) quartile: >77 bpm). There were no significant differences in gender, prevalence of diabetes, hypertension, left ventricular ejection fraction, or medications but a higher prevalence of coronary artery disease was noted among patients in the lower quartiles of average heart rate. After a mean follow-up of 5.8±1.8 years, 60 patients (14.0%) developed new-onset AF. The annual incidence of new-onset AF was highest amongst those at the lowest quartile of average heart rate (9.39%/year) as compared to those amongst other quartiles. Cox regression analysis revealed that increasing age, decreasing quartile of average heart rate, and the use of calcium channel blocker were associated with increased risk of new-onset AF. CONCLUSIONS Average heart rate predicts new AF.
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Monfredi O, Boyett MR. Sick sinus syndrome and atrial fibrillation in older persons - A view from the sinoatrial nodal myocyte. J Mol Cell Cardiol 2015; 83:88-100. [PMID: 25668431 DOI: 10.1016/j.yjmcc.2015.02.003] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Revised: 01/30/2015] [Accepted: 02/02/2015] [Indexed: 01/02/2023]
Abstract
Sick sinus syndrome remains a highly relevant clinical entity, being responsible for the implantation of the majority of electronic pacemakers worldwide. It is an infinitely more complex disease than it was believed when first described in the mid part of the 20th century. It not only involves the innate leading pacemaker region of the heart, the sinoatrial node, but also the atrial myocardium, predisposing to atrial tachydysrhythmias. It remains controversial as to whether the dysfunction of the sinoatrial node directly causes the dysfunction of the atrial myocardium, or vice versa, or indeed whether these two aspects of the condition arise through some related underlying pathological mechanism, such as extracellular matrix remodeling, i.e., fibrosis. This review aims to shed new light on the myriad possible contributing factors in the development of sick sinus syndrome, with a particular focus on the sinoatrial nodal myocyte. This article is part of a Special Issue entitled CV Aging.
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Affiliation(s)
- O Monfredi
- Institute of Cardiovascular Sciences, University of Manchester, 46 Grafton Street, Manchester M13 9NT, UK.
| | - M R Boyett
- Institute of Cardiovascular Sciences, University of Manchester, 46 Grafton Street, Manchester M13 9NT, UK
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