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Sung DJ, Jeon YK, Choi J, Kim B, Golpasandi S, Park SW, Oh SB, Bae YM. Protective effect of low-intensity treadmill exercise against acetylcholine-calcium chloride-induced atrial fibrillation in mice. Korean J Physiol Pharmacol 2022; 26:313-323. [PMID: 36039732 PMCID: PMC9437371 DOI: 10.4196/kjpp.2022.26.5.313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 07/20/2022] [Accepted: 07/21/2022] [Indexed: 06/15/2023]
Abstract
Atrial fibrillation (AF) is the most common supraventricular arrhythmia, and it corresponds highly with exercise intensity. Here, we induced AF in mice using acetylcholine (ACh)-CaCl2 for 7 days and aimed to determine the appropriate exercise intensity (no, low, moderate, high) to protect against AF by running the mice at different intensities for 4 weeks before the AF induction by ACh-CaCl2. We examined the AF-induced atrial remodeling using electrocardiogram, patch-clamp, and immunohistochemistry. After the AF induction, heart rate, % increase of heart rate, and heart weight/body weight ratio were significantly higher in all the four AF groups than in the normal control; highest in the high-ex AF and lowest in the low-ex (lower than the no-ex AF), which indicates that low-ex treated the AF. Consistent with these changes, G protein-gated inwardly rectifying K+ currents, which were induced by ACh, increased in an exercise intensity-dependent manner and were lower in the low-ex AF than the no-ex AF. The peak level of Ca2+ current (at 0 mV) increased also in an exercise intensity-dependent manner and the inactivation time constants were shorter in all AF groups except for the low-ex AF group, in which the time constant was similar to that of the control. Finally, action potential duration was shorter in all the four AF groups than in the normal control; shortest in the high-ex AF and longest in the low-ex AF. Taken together, we conclude that low-intensity exercise protects the heart from AF, whereas high-intensity exercise might exacerbate AF.
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Affiliation(s)
- Dong-Jun Sung
- Department of Sport and Health Studies, College of Biomedical and Health Science, Konkuk University, Chungju 27478, Korea
- Sports Convergence Institute, Chungju 27478, Korea
- Center for Metabolic Diseases, Konkuk University, Chungju 27478, Korea
| | - Yong-Kyun Jeon
- Department of Physical Education at the Graduate School of Education, Dankook University, Yongin 16890, Korea
| | - Jaeil Choi
- Department of Physical Education at the Graduate School of Education, Dankook University, Yongin 16890, Korea
| | - Bokyung Kim
- Department of Physiology, KU Open Innovation Center, Research Institute of Medical Science, Konkuk University School of Medicine, Chungju 27478, Korea
| | - Shadi Golpasandi
- Department of Physiology, KU Open Innovation Center, Research Institute of Medical Science, Konkuk University School of Medicine, Chungju 27478, Korea
| | - Sang Woong Park
- Department of Emergency Medical Services, College of Health Sciences, Eulji University, Seongam 13135, Korea
| | - Seung-Bum Oh
- Department of Sport and Health Studies, College of Biomedical and Health Science, Konkuk University, Chungju 27478, Korea
| | - Young Min Bae
- Department of Physiology, KU Open Innovation Center, Research Institute of Medical Science, Konkuk University School of Medicine, Chungju 27478, Korea
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Kharbanda RK, van der Does WFB, van Staveren LN, Taverne YJHJ, Bogers AJJC, de Groot NMS. Vagus Nerve Stimulation and Atrial Fibrillation: Revealing the Paradox. Neuromodulation 2022; 25:356-365. [PMID: 35190246 DOI: 10.1016/j.neurom.2022.01.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Revised: 12/28/2021] [Accepted: 01/04/2022] [Indexed: 12/18/2022]
Abstract
BACKGROUND AND OBJECTIVE The cardiac autonomic nervous system (CANS) plays an important role in the pathophysiology of atrial fibrillation (AF). Cardiovascular disease can cause an imbalance within the CANS, which may contribute to the initiation and maintenance of AF. Increased understanding of neuromodulation of the CANS has resulted in novel emerging therapies to treat cardiac arrhythmias by targeting different circuits of the CANS. Regarding AF, neuromodulation therapies targeting the vagus nerve have yielded promising outcomes. However, targeting the vagus nerve can be both pro-arrhythmogenic and anti-arrhythmogenic. Currently, these opposing effects of vagus nerve stimulation (VNS) have not been clearly described. The aim of this review is therefore to discuss both pro-arrhythmogenic and anti-arrhythmogenic effects of VNS and recent advances in clinical practice and to provide future perspectives for VNS to treat AF. MATERIALS AND METHODS A comprehensive review of current literature on VNS and its pro-arrhythmogenic and anti-arrhythmogenic effects on atrial tissue was performed. Both experimental and clinical studies are reviewed and discussed separately. RESULTS VNS exhibits both pro-arrhythmogenic and anti-arrhythmogenic effects. The anatomical site and stimulation settings during VNS play a crucial role in determining its effect on cardiac electrophysiology. Since the last decade, there is accumulating evidence from experimental studies and randomized clinical studies that low-level VNS (LLVNS), below the bradycardia threshold, is an effective treatment for AF. CONCLUSION LLVNS is a promising novel therapeutic modality to treat AF and further research will further elucidate the underlying anti-arrhythmogenic mechanisms, optimal stimulation settings, and site to apply LLVNS.
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Affiliation(s)
- Rohit K Kharbanda
- Department of Cardiology, Erasmus Medical Center, Rotterdam, The Netherlands; Department of Cardiothoracic Surgery, Erasmus Medical Center, Rotterdam, The Netherlands
| | | | | | - Yannick J H J Taverne
- Department of Cardiothoracic Surgery, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Ad J J C Bogers
- Department of Cardiothoracic Surgery, Erasmus Medical Center, Rotterdam, The Netherlands
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Hanna P, Buch E, Stavrakis S, Meyer C, Tompkins JD, Ardell JL, Shivkumar K. Neuroscientific therapies for atrial fibrillation. Cardiovasc Res 2021; 117:1732-1745. [PMID: 33989382 PMCID: PMC8208752 DOI: 10.1093/cvr/cvab172] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 05/13/2021] [Indexed: 02/06/2023] Open
Abstract
The cardiac autonomic nervous system (ANS) plays an integral role in normal cardiac physiology as well as in disease states that cause cardiac arrhythmias. The cardiac ANS, comprised of a complex neural hierarchy in a nested series of interacting feedback loops, regulates atrial electrophysiology and is itself susceptible to remodelling by atrial rhythm. In light of the challenges of treating atrial fibrillation (AF) with conventional pharmacologic and myoablative techniques, increasingly interest has begun to focus on targeting the cardiac neuraxis for AF. Strong evidence from animal models and clinical patients demonstrates that parasympathetic and sympathetic activity within this neuraxis may trigger AF, and the ANS may either induce atrial remodelling or undergo remodelling itself to serve as a substrate for AF. Multiple nexus points within the cardiac neuraxis are therapeutic targets, and neuroablative and neuromodulatory therapies for AF include ganglionated plexus ablation, epicardial botulinum toxin injection, vagal nerve (tragus) stimulation, renal denervation, stellate ganglion block/resection, baroreceptor activation therapy, and spinal cord stimulation. Pre-clinical and clinical studies on these modalities have had promising results and are reviewed here.
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Affiliation(s)
- Peter Hanna
- University of California Los Angeles (UCLA) Cardiac Arrhythmia Center, David Geffen School of Medicine, UCLA, 100 Medical Plaza, Suite 660, Los Angeles, CA 90095, USA
- Neurocardiology Research Program of Excellence, David Geffen School of Medicine, UCLA, 100 Medical Plaza, Suite 660, Los Angeles, CA 90095, USA
- Molecular, Cellular & Integrative Physiology Program, David Geffen School of Medicine, UCLA, 100 Medical Plaza, Suite 660, Los Angeles, CA 90095, USA
| | - Eric Buch
- University of California Los Angeles (UCLA) Cardiac Arrhythmia Center, David Geffen School of Medicine, UCLA, 100 Medical Plaza, Suite 660, Los Angeles, CA 90095, USA
| | - Stavros Stavrakis
- Heart Rhythm Institute, University of Oklahoma Health Sciences Center, 1100 N Lindsay Ave, Oklahoma City, OK 73104, USA
| | - Christian Meyer
- Division of Cardiology, cardiac Neuro- and Electrophysiology Research Consortium (cNEP), EVK Düsseldorf, Teaching Hospital University of Düsseldorf, Kirchfeldstraße 40, 40217 Düsseldorf, Germany
- Institute of Neural and Sensory Physiology, cardiac Neuro- and Electrophysiology Research Consortium (cNEP), University of Düsseldorf, Universitätsstraße 1, 40225 Düsseldorf, Germany
| | - John D Tompkins
- University of California Los Angeles (UCLA) Cardiac Arrhythmia Center, David Geffen School of Medicine, UCLA, 100 Medical Plaza, Suite 660, Los Angeles, CA 90095, USA
- Neurocardiology Research Program of Excellence, David Geffen School of Medicine, UCLA, 100 Medical Plaza, Suite 660, Los Angeles, CA 90095, USA
| | - Jeffrey L Ardell
- University of California Los Angeles (UCLA) Cardiac Arrhythmia Center, David Geffen School of Medicine, UCLA, 100 Medical Plaza, Suite 660, Los Angeles, CA 90095, USA
- Neurocardiology Research Program of Excellence, David Geffen School of Medicine, UCLA, 100 Medical Plaza, Suite 660, Los Angeles, CA 90095, USA
- Molecular, Cellular & Integrative Physiology Program, David Geffen School of Medicine, UCLA, 100 Medical Plaza, Suite 660, Los Angeles, CA 90095, USA
| | - Kalyanam Shivkumar
- University of California Los Angeles (UCLA) Cardiac Arrhythmia Center, David Geffen School of Medicine, UCLA, 100 Medical Plaza, Suite 660, Los Angeles, CA 90095, USA
- Neurocardiology Research Program of Excellence, David Geffen School of Medicine, UCLA, 100 Medical Plaza, Suite 660, Los Angeles, CA 90095, USA
- Molecular, Cellular & Integrative Physiology Program, David Geffen School of Medicine, UCLA, 100 Medical Plaza, Suite 660, Los Angeles, CA 90095, USA
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Ivanova AD, Filatova TS, Abramochkin DV, Atkinson A, Dobrzynski H, Kokaeva ZG, Merzlyak EM, Pustovit KB, Kuzmin VS. Attenuation of inward rectifier potassium current contributes to the α1-adrenergic receptor-induced proarrhythmicity in the caval vein myocardium. Acta Physiol (Oxf) 2021; 231:e13597. [PMID: 33306261 DOI: 10.1111/apha.13597] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Revised: 11/19/2020] [Accepted: 12/07/2020] [Indexed: 12/31/2022]
Abstract
AIM This study is aimed at investigation of electrophysiological effects of α1-adrenoreceptor (α1-AR) stimulation in the rat superior vena cava (SVC) myocardium, which is one of the sources of proarrhythmic activity. METHODS α1-ARs agonists (phenylephrine-PHE or norepinephrine in presence of atenolol-NE + ATL) were applied to SVC and atrial tissue preparations or isolated cardiomyocytes, which were examined using optical mapping, glass microelectrodes or whole-cell patch clamp. α1-ARs distribution was evaluated using immunofluorescence. Kir2.X mRNA and protein level were estimated using RT-PCR and Western blotting. RESULTS PHE or NE + ATL application caused a significant suppression of the conduction velocity (CV) of excitation and inexcitability in SVC, an increase in the duration of electrically evoked action potentials (APs), a decrease in the maximum upstroke velocity (dV/dtmax ) and depolarization of the resting membrane potential (RMP) in SVC to a greater extent than in atria. The effects induced by α1-ARs activation in SVC were attenuated by protein kinase C inhibition (PKC). The whole-cell patch clamp revealed PHE-induced suppression of outward component of IK1 inward rectifier current in isolated SVC, but not atrial myocytes. These effects can be mediated by α1A subtype of α-ARs found in abundance in rat SVC. The basal IK1 level in SVC was much lower than in atria as a result of the weaker expression of Kir2.2 channels. CONCLUSION Therefore, the reduced density of IK1 in rat SVC cardiomyocytes and sensitivity of this current to α1A-AR stimulation via PKC-dependent pathways might lead to proarrhythmic conduction in SVC myocardium by inducing RMP depolarization, AP prolongation, CV and dV/dtmax decrease.
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Affiliation(s)
- Alexandra D. Ivanova
- Department of Human and Animal Physiology Lomonosov Moscow State University Moscow Russia
| | - Tatiana S. Filatova
- Department of Human and Animal Physiology Lomonosov Moscow State University Moscow Russia
- Department of Physiology Pirogov Russian National Research Medical University Moscow Russia
| | - Denis V. Abramochkin
- Department of Human and Animal Physiology Lomonosov Moscow State University Moscow Russia
- Department of Physiology Pirogov Russian National Research Medical University Moscow Russia
- Laboratory of Cardiac Electrophysiology National Medical Research Center for Cardiology Moscow Russia
| | - Andrew Atkinson
- Faculty of Biology, Medicine and Health University of Manchester Manchester UK
| | - Halina Dobrzynski
- Faculty of Biology, Medicine and Health University of Manchester Manchester UK
- Heart Embryology and Anatomy Research Team Department of Anatomy Jagiellonian University Medical College Cracow Poland
| | - Zarema G. Kokaeva
- Department of Human and Animal Physiology Lomonosov Moscow State University Moscow Russia
| | - Ekaterina M. Merzlyak
- Shemiakin‐Ovchinnikov Institute of Bioorganic Chemistry Russian Academy of Science Moscow Russia
| | - Ksenia B. Pustovit
- Department of Human and Animal Physiology Lomonosov Moscow State University Moscow Russia
| | - Vladislav S. Kuzmin
- Department of Human and Animal Physiology Lomonosov Moscow State University Moscow Russia
- Department of Physiology Pirogov Russian National Research Medical University Moscow Russia
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Abstract
I mbalance of the sympathetic and parasympathetic nervous systems is probably the most prevalent autonomic mechanism underlying many a rrhythmias . Recently, vagus nerve stimulation ( VNS has emerged as a novel therapeutic modality to treat arrhythmias through its anti adrenergic and anti inflammatory actions . C linical trials applying VNS to the cervical vagus nerve in heart failure pati en ts yielded conflicting results, possibly due to limited understanding of the optimal stimulation parameters for the targeted cardiovascular diseases. Transcutaneous VNS by stimulating the auricular branch of the vagus nerve, has attracted great attention d ue to its noninvasiveness. In this r eview, we summarize current knowledge about the complex relationship between VNS and cardiac arrhythmias and discuss recent advances in using VNS , particularly transcutaneous VNS , to treat arrhythmias.
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Affiliation(s)
- Chengzhe Liu
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China.,Cardiac Autonomic Nervous System Research Center of Wuhan Univer s ity, Wuhan, China.,Cardiovascular Research Institute, Wuhan University, Wuhan, China.,Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Hong Jiang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China.,Cardiac Autonomic Nervous System Research Center of Wuhan Univer s ity, Wuhan, China.,Cardiovascular Research Institute, Wuhan University, Wuhan, China.,Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Lilei Yu
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China.,Cardiac Autonomic Nervous System Research Center of Wuhan Univer s ity, Wuhan, China.,Cardiovascular Research Institute, Wuhan University, Wuhan, China.,Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Sunny S Po
- Heart Rhythm Institute and Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, O K USA
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7
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Zhu C, Hanna P, Rajendran PS, Shivkumar K. Neuromodulation for Ventricular Tachycardia and Atrial Fibrillation: A Clinical Scenario-Based Review. JACC Clin Electrophysiol 2019; 5:881-96. [PMID: 31439288 DOI: 10.1016/j.jacep.2019.06.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 05/30/2019] [Accepted: 06/04/2019] [Indexed: 12/17/2022]
Abstract
Autonomic dysregulation in cardiovascular disease plays a major role in the pathogenesis of arrhythmias. Cardiac neural control relies on complex feedback loops consisting of efferent and afferent limbs, which carry sympathetic and parasympathetic signals from the brain to the heart and sensory signals from the heart to the brain. Cardiac disease leads to neural remodeling and sympathovagal imbalances with arrhythmogenic effects. Preclinical studies of modulation at central and peripheral levels of the cardiac autonomic nervous system have yielded promising results, leading to early stage clinical studies of these techniques in atrial fibrillation and refractory ventricular arrhythmias, particularly in patients with inherited primary arrhythmia syndromes and structural heart disease. However, significant knowledge gaps in basic cardiac neurophysiology limit the success of these neuromodulatory therapies. This review discusses the recent advances in neuromodulation for cardiac arrhythmia management, with a clinical scenario-based approach aimed at bringing neurocardiology closer to the realm of the clinical electrophysiologist.
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8
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Chang TY, Lin CY, Chen SA. Vagal impact of cryoballoon ablation during pulmonary vein isolation. Int J Cardiol 2018; 265:132-133. [PMID: 29885679 DOI: 10.1016/j.ijcard.2018.04.132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 04/30/2018] [Indexed: 11/28/2022]
Affiliation(s)
- Ting-Yung Chang
- Heart Rhythm Center, Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Division of Cardiology, Taipei Veterans General Hospital, Taipei, Taiwan; Institute of Clinical Medicine, and Cardiovascular Research Institute, National Yang-Ming University, Taipei, Taiwan
| | - Chin-Yu Lin
- Heart Rhythm Center, Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Division of Cardiology, Taipei Veterans General Hospital, Taipei, Taiwan; Institute of Clinical Medicine, and Cardiovascular Research Institute, National Yang-Ming University, Taipei, Taiwan; Department of Medicine, Taipei Veterans General Hospital, Yuan-Shan Branch, I-Lan, Taiwan
| | - Shih-Ann Chen
- Heart Rhythm Center, Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Division of Cardiology, Taipei Veterans General Hospital, Taipei, Taiwan; Institute of Clinical Medicine, and Cardiovascular Research Institute, National Yang-Ming University, Taipei, Taiwan.
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9
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Scridon A, Şerban RC, Chevalier P. Atrial fibrillation: Neurogenic or myogenic? Arch Cardiovasc Dis 2018; 111:59-69. [DOI: 10.1016/j.acvd.2017.11.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 11/07/2017] [Accepted: 11/13/2017] [Indexed: 01/08/2023]
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Shivkumar K, Ajijola OA, Anand I, Armour JA, Chen PS, Esler M, De Ferrari GM, Fishbein MC, Goldberger JJ, Harper RM, Joyner MJ, Khalsa SS, Kumar R, Lane R, Mahajan A, Po S, Schwartz PJ, Somers VK, Valderrabano M, Vaseghi M, Zipes DP. Clinical neurocardiology defining the value of neuroscience-based cardiovascular therapeutics. J Physiol 2016; 594:3911-54. [PMID: 27114333 PMCID: PMC4945719 DOI: 10.1113/jp271870] [Citation(s) in RCA: 192] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2016] [Accepted: 04/08/2016] [Indexed: 12/13/2022] Open
Abstract
The autonomic nervous system regulates all aspects of normal cardiac function, and is recognized to play a critical role in the pathophysiology of many cardiovascular diseases. As such, the value of neuroscience-based cardiovascular therapeutics is increasingly evident. This White Paper reviews the current state of understanding of human cardiac neuroanatomy, neurophysiology, pathophysiology in specific disease conditions, autonomic testing, risk stratification, and neuromodulatory strategies to mitigate the progression of cardiovascular diseases.
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Affiliation(s)
- Kalyanam Shivkumar
- UCLA Cardiac Arrhythmia Center and Neurocardiology Research Center of Excellence, Los Angeles, CA, USA
| | - Olujimi A Ajijola
- UCLA Cardiac Arrhythmia Center and Neurocardiology Research Center of Excellence, Los Angeles, CA, USA
| | - Inder Anand
- Department of Cardiology, University of Minnesota Medical School, Minneapolis, MN, USA
| | - J Andrew Armour
- UCLA Cardiac Arrhythmia Center and Neurocardiology Research Center of Excellence, Los Angeles, CA, USA
| | - Peng-Sheng Chen
- Krannert Institute of Cardiology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Murray Esler
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | | | - Michael C Fishbein
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Jeffrey J Goldberger
- Division of Cardiology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Ronald M Harper
- Department of Neurobiology and the Brain Research Institute, University of California, Los Angeles, CA, USA
| | - Michael J Joyner
- Division of Cardiovascular Diseases, Mayo Clinic and Mayo Foundation, Rochester, MN, USA
| | | | - Rajesh Kumar
- Departments of Anesthesiology and Radiological Sciences, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Richard Lane
- Department of Psychiatry, University of Arizona College of Medicine, Tucson, AZ, USA
| | - Aman Mahajan
- Department of Anesthesia, UCLA, Los Angeles, CA, USA
| | - Sunny Po
- Heart Rhythm Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- University of Tulsa Oxley College of Health Sciences, Tulsa, OK, USA
| | - Peter J Schwartz
- Center for Cardiac Arrhythmias of Genetic Origin, IRCCS Instituto Auxologico Italiano, c/o Centro Diagnostico e di Ricerrca San Carlo, Milan, Italy
| | - Virend K Somers
- Division of Cardiovascular Diseases, Mayo Clinic and Mayo Foundation, Rochester, MN, USA
| | - Miguel Valderrabano
- Methodist DeBakey Heart and Vascular Center and Methodist Hospital Research Institute, Houston Methodist Hospital, Houston, TX, USA
| | - Marmar Vaseghi
- UCLA Cardiac Arrhythmia Center and Neurocardiology Research Center of Excellence, Los Angeles, CA, USA
| | - Douglas P Zipes
- Indiana University School of Medicine, Indianapolis, IN, USA
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11
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Laszlo R, Steinacker JM. [Atrial fibrillation and physical activity. An overview]. Herz 2016; 41:131-7. [PMID: 26407697 DOI: 10.1007/s00059-015-4352-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 07/31/2015] [Accepted: 08/09/2015] [Indexed: 10/23/2022]
Abstract
A training-induced increase in vagal tone, left atrial enlargement and high atrial volume load due to exercise can theoretically favor induction and continuation of atrial fibrillation (AF) in (endurance) athletes. However, there is currently no evidence for a higher occurrence of AF in young endurance athletes in comparison to an age-matched normal population. The correlate of long-term endurance training results in proarrhythmogenic atrial remodeling in a rat model. The results of some studies also suggest that there may be atrial remodeling in humans, which might be an explanation for the comparatively higher incidence of AF in veteran athletes, whereby the relative risk might have been overestimated due to methodological problems, e.g. due to insufficient consideration of "new" AF risk factors. To date, there are no indications for an increased risk of AF due to normal physical activity: on the contrary, moderate physical activity seems to decrease the risk for AF. For an individual evaluation of sports participation of patients with AF, the overall cardiac situation, atrioventricular conduction during exercise, a possible oral anticoagulation as well as the sport and training intensity practiced are important. Well-adapted training for patients with AF has to be considered as safe and effective in terms of the overall positive effects of physical activity in patients with cardiovascular problems, for example due to a positive influence on cardiovascular risk factors.
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Mahida S, Sacher F, Derval N, Berte B, Yamashita S, Hooks D, Denis A, Amraoui S, Hocini M, Haissaguerre M, Jais P. Science Linking Pulmonary Veins and Atrial Fibrillation. Arrhythm Electrophysiol Rev 2015; 4:40-3. [PMID: 26835098 DOI: 10.15420/aer.2015.4.1.40] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2015] [Accepted: 03/18/2015] [Indexed: 12/30/2022] Open
Abstract
Over the past few decades, significant progress has been made in understanding the mechanistic basis of atrial fibrillation (AF). One of the most important discoveries in this context has been that pulmonary veins (PV) play a prominent role in the pathogenesis of AF. PV isolation has since become the most widely used technique for treatment of paroxysmal AF. Multiple studies have demonstrated that the electrophysiological and anatomical characteristics of PVs create a proarrhythmogenic substrate. The following review discusses the mechanistic links between PVs and AF.
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Affiliation(s)
- Saagar Mahida
- Hôpital Cardiologique du Haut-Lévêque and Université Victor Segalen Bordeaux II, Bordeaux, France
| | - Frederic Sacher
- Hôpital Cardiologique du Haut-Lévêque and Université Victor Segalen Bordeaux II, Bordeaux, France
| | - Nicolas Derval
- Hôpital Cardiologique du Haut-Lévêque and Université Victor Segalen Bordeaux II, Bordeaux, France
| | - Benjamin Berte
- Hôpital Cardiologique du Haut-Lévêque and Université Victor Segalen Bordeaux II, Bordeaux, France
| | - Seigo Yamashita
- Hôpital Cardiologique du Haut-Lévêque and Université Victor Segalen Bordeaux II, Bordeaux, France
| | - Darren Hooks
- Hôpital Cardiologique du Haut-Lévêque and Université Victor Segalen Bordeaux II, Bordeaux, France
| | - Arnaud Denis
- Hôpital Cardiologique du Haut-Lévêque and Université Victor Segalen Bordeaux II, Bordeaux, France
| | - Sana Amraoui
- Hôpital Cardiologique du Haut-Lévêque and Université Victor Segalen Bordeaux II, Bordeaux, France
| | - Meleze Hocini
- Hôpital Cardiologique du Haut-Lévêque and Université Victor Segalen Bordeaux II, Bordeaux, France
| | - Michel Haissaguerre
- Hôpital Cardiologique du Haut-Lévêque and Université Victor Segalen Bordeaux II, Bordeaux, France
| | - Pierre Jais
- Hôpital Cardiologique du Haut-Lévêque and Université Victor Segalen Bordeaux II, Bordeaux, France
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Dai M, Bao M, Liao J, Yu L, Tang Y, Huang H, Wang X, Huang C. Effects of low-level carotid baroreflex stimulation on atrial electrophysiology. J Interv Card Electrophysiol 2015; 43:111-9. [DOI: 10.1007/s10840-015-9976-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Accepted: 01/20/2015] [Indexed: 11/28/2022]
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Liao K, Yu L, Zhou X, Saren G, Wang S, Wang Z, Huang B, Yang K, Jiang H. Low-level baroreceptor stimulation suppresses atrial fibrillation by inhibiting ganglionated plexus activity. Can J Cardiol 2015; 31:767-74. [PMID: 26022989 DOI: 10.1016/j.cjca.2015.01.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Revised: 01/13/2015] [Accepted: 01/17/2015] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND The autonomic nervous system (ANS) plays an important role in the initiation and maintenance of atrial fibrillation (AF), and modulation of the ANS function may contribute to AF control. METHODS Anesthetized dogs received either sham treatment (SHAM group, n = 8) or low-level carotid baroreceptor stimulation (LL-CBS) treatment (LL-CBS group, n = 8). The stimulation voltage was set at 80% below the threshold. To simulate focal AF, high-frequency stimulation (HFS) was applied to local nerves during the atrial refractory period. Multielectrode catheters were attached to the atria and all the pulmonary veins to determine the changes in the AF threshold (AF-TH), the atrial effective refractory period (AERP), and the window of vulnerability (WOV) during HFS in both groups. Microelectrodes were inserted into the anterior right ganglionated plexus (ARGP) to record neural firing. RESULTS HFS induced sinus rate (SR) slowing in the superior left ganglionated plexus (SLGP). LL-CBS induced a progressive increase in AF-TH and AERP at all sites and a significant decrease in the sum of WOV at 2 hours (all P < 0.05). LL-CBS inhibited the ability of SLGP stimulation to slow the SR and the mean values of frequency and amplitude of ARGP neural activity compared with the SHAM group (all P < 0.05). CONCLUSIONS LL-CBS suppressed AF inducibility by inhibiting the neural activity of ganglionated plexuses. LL-CBS may serve as a novel therapeutic modality to treat AF.
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MOUNTANTONAKIS STAVROSE, ELKASSABANY NABIL, KONDAPALLI LAVANYA, MARCHLINSKI FRANCISE, MANDEL JEFFE, HUTCHINSON MATHEWD. Provocation of Atrial Fibrillation Triggers During Ablation: Does the Use of General Anesthesia Affect Inducibility? J Cardiovasc Electrophysiol 2014; 26:16-20. [DOI: 10.1111/jce.12512] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2014] [Revised: 07/28/2014] [Accepted: 07/31/2014] [Indexed: 12/18/2022]
Affiliation(s)
| | - NABIL ELKASSABANY
- Department of Anesthesiology and Critical Care; Hospital of the University of Pennsylvania; Philadelphia Pennsylvania USA
| | - LAVANYA KONDAPALLI
- Cardiovascular Division; Department of Medicine; Hospital of the University of Pennsylvania; Philadelphia Pennsylvania USA
| | - FRANCIS E. MARCHLINSKI
- Cardiovascular Division; Department of Medicine; Hospital of the University of Pennsylvania; Philadelphia Pennsylvania USA
| | - JEFF E. MANDEL
- Department of Anesthesiology and Critical Care; Hospital of the University of Pennsylvania; Philadelphia Pennsylvania USA
| | - MATHEW D. HUTCHINSON
- Cardiovascular Division; Department of Medicine; Hospital of the University of Pennsylvania; Philadelphia Pennsylvania USA
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Linz D, Ukena C, Mahfoud F, Neuberger HR, Böhm M. Atrial Autonomic Innervation. J Am Coll Cardiol 2014; 63:215-24. [DOI: 10.1016/j.jacc.2013.09.020] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Revised: 09/03/2013] [Accepted: 09/10/2013] [Indexed: 10/26/2022]
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Xie X, Lee SW, Johnson C, Ippolito J, KenKnight BH, Tolkacheva EG. Intermittent vagal nerve stimulation alters the electrophysiological properties of atrium in the myocardial infarction rat model. Annu Int Conf IEEE Eng Med Biol Soc 2014; 2014:1575-1578. [PMID: 25570272 DOI: 10.1109/embc.2014.6943904] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Intermittent vagal nerve stimulation (VNS) has emerged as a potential therapy to treat cardiovascular diseases by delivering electrical stimulation to the vagus nerves. The purpose of this study was to investigate the electrophysiological changes in the atrium resulting from long-term intermittent VNS therapy in the chronic myocardial infarction (MI) rat model. MI was induced via left anterior descending coronary artery (LAD) ligation in male Sprague-Dawley rats, randomized into two groups: MI (implanted with nonfunctional VNS stimulators) and MI-VNS (implanted with functional VNS stimulators and received chronic intermittent VNS treatment) groups. Further, a sham group was used as control in which MI was not performed and received nonfunctional VNS stimulators. At 12 weeks, optical mapping of right atrium (RA) of sinus rhythm was performed. Our results demonstrated that chronic MI changed the electrical properties of the atrium action potentials and resulted in reduced action potential duration at 50% (APD50) and 80% (APD80) repolarization. Chronic right cervical VNS restored the APD back to healthy heart APD values. Additionally, APD heterogeneity index increased as a result of the chronic MI. Chronic VNS was not found to alter this increase. By calculating PR intervals from weekly ECG recordings of anaesthetized rats, we demonstrated that chronic MI and intermittent VNS did not affect the AV conduction time from the atria to the ventricles. From our study, we conclude the MI decreased the APD and increased APD spatial dispersion. VNS increased the APD back to healthy normal values but did change the APD spatial dispersion and the electrical conduction in the RA.
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Shen X, Scherlag BJ, He B, Sun J, Mei G, Po SS. The Role of the Atrial Neural Network In Atrial Fibrillation: The Metastatic Progression Hypothesis. J Atr Fibrillation 2013; 6:882. [PMID: 28496879 DOI: 10.4022/jafib.882] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Revised: 08/08/2013] [Accepted: 08/08/2013] [Indexed: 11/10/2022]
Abstract
With the advent of catheter ablation of atrial fibrillation (AF) there has been acceleration in our understanding of the mechanisms underlying the etiology of this common clinical arrhythmia. In this regard, the role of the intrinsic cardiac autonomic nervous system in the initiation and maintenance of AF began to receive attention in numerous experimental and clinical investigations. Up to now, the focus has been on the large ganglionated plexi (GP) which are located in the posterior left atrium mainly at the pulmonary vein-atrial junctions. As long term outcomes have been reported and single procedures have indicated diminished success rates particularly for persistent/long standing persistent AF, emphasis has begun to shift away from the pulmonary vein isolation (PVI) alone as well as GP ablation with or without PVI. An understanding of the atrial substrate represented by the extensions of the intrinsic cardiac autonomic system constituting the atrial neural network is beginning to evolve. In this review, the contribution of the intrinsic cardiac autonomic nervous system to the etiology of AF is addressed, particularly in regard to the greater prevalence of AF in the elderly. In addition, we emphasize the involvement of the atrial neural network in the "metastatic" progression of paroxysmal to persistent and long standing persistent forms of AF.
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Affiliation(s)
- X Shen
- Department of Cardiology, Sir Run Run Shaw Hospital, 3 Qing Chun Road East, Hangzhou, Zhejiang Province, China,310016
| | - B J Scherlag
- Heart Rhythm Institute, University of Oklahoma Health Sciences Center,Oklahoma City, OK
| | - B He
- Heart Rhythm Institute, University of Oklahoma Health Sciences Center,Oklahoma City, OK
| | - J Sun
- Heart Rhythm Institute, University of Oklahoma Health Sciences Center,Oklahoma City, OK
| | - G Mei
- Heart Rhythm Institute, University of Oklahoma Health Sciences Center,Oklahoma City, OK
| | - S S Po
- Heart Rhythm Institute, University of Oklahoma Health Sciences Center,Oklahoma City, OK
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Lo LW, Scherlag BJ, Chang HY, Lin YJ, Chen SA, Po SS. Paradoxical long-term proarrhythmic effects after ablating the “head station” ganglionated plexi of the vagal innervation to the heart. Heart Rhythm 2013; 10:751-7. [DOI: 10.1016/j.hrthm.2013.01.030] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2012] [Indexed: 12/21/2022]
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NG JASON, PASSMAN RODS, ARORA RISHI, KADISH ALANH, GOLDBERGER JEFFREYJ. Paradoxical Change in Atrial Fibrillation Dominant Frequencies with Baroreflex-Mediated Parasympathetic Stimulation with Phenylephrine Infusion. J Cardiovasc Electrophysiol 2012; 23:1045-50. [DOI: 10.1111/j.1540-8167.2012.02362.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Lombardi F, Belletti S, Battezzati PM, Lomuscio A. Acupuncture for paroxysmal and persistent atrial fibrillation: An effective non-pharmacological tool? World J Cardiol 2012; 4:60-5. [PMID: 22451853 PMCID: PMC3312232 DOI: 10.4330/wjc.v4.i3.60] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Revised: 01/10/2012] [Accepted: 01/17/2012] [Indexed: 02/06/2023] Open
Abstract
In Traditional Chinese Medicine, stimulation of the Neiguan spot has been utilized to treat palpitations and symptoms related to different cardiovascular diseases. We evaluated whether acupuncture might exert an antiarrhythmic effect on patients with paroxysmal or persistent atrial fibrillation (AF). Two sets of data are reviewed. The first included patients with persistent AF who underwent electrical cardioversion to restore sinus rhythm. The second included patients with symptomatic paroxysmal AF. All subjects had normal ventricular function. Acupuncture treatment consisted of 10 acupuncture sessions on a once a week basis with puncturing of the Neiguan, Shenmen and Xinshu spots. In patients with persistent AF, the recurrence rate after acupuncture treatment was similar to that observed in patients on amiodarone, but significantly smaller than that measured after sham acupuncture treatment or in the absence of any antiarrhythmic drugs. In a small group of patients with paroxysmal AF, acupuncture resulted in a significant reduction in the number and duration of symptomatic AF episodes. In conclusion, we observed that acupuncture of the Neiguan spot was associated with an antiarrhythmic effect, which was evident in patients with both persistent and paroxysmal AF. These preliminary data, observed in 2 small groups of AF patients, need to be validated in a larger population but strongly suggest that acupuncture may be an effective non-invasive and safe antiarrhythmic tool in the management of these patients.
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Affiliation(s)
- Federico Lombardi
- Federico Lombardi, Sebastiano Belletti, Pier Maria Battezzati, Alberto Lomuscio, Department of Medicine, Surgery and Dentistry, University of Milan, 20147 Milan, Italy
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Yu L, Scherlag BJ, Sha Y, Li S, Sharma T, Nakagawa H, Jackman WM, Lazzara R, Jiang H, Po SS. Interactions between atrial electrical remodeling and autonomic remodeling: how to break the vicious cycle. Heart Rhythm 2011; 9:804-9. [PMID: 22214613 DOI: 10.1016/j.hrthm.2011.12.023] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Indexed: 11/29/2022]
Abstract
BACKGROUND The mechanism(s) underlying the maintenance of atrial fibrillation (AF) during the first few hours after AF was initiated remains poorly understood. OBJECTIVE To investigate the roles of the intrinsic cardiac autonomic nervous system in the maintenance of AF at the early stage. METHODS In 10 anesthetized dogs, we attached multielectrode catheters on atria and pulmonary veins. Microelectrodes inserted into the anterior right ganglionated plexi recorded neural activity. At baseline, programmed stimulation determined the effective refractory period (ERP) and window of vulnerability (WOV), a measure of AF inducibility. For the next 6 hours, AF was simulated by rapid atrial pacing (RAP) and the same parameters were measured hourly during sinus rhythm. A circular catheter was positioned in the superior vena cava for high-frequency stimulation (20 Hz) of the adjacent vagal preganglionics. During 4-6 hours of RAP, we delivered low-level vagal stimulation in the superior vena cava (LL-SVCS), 50% below that which induced slowing of the sinus rate. RESULTS During the 6-hour RAP, there was a progressive decrease in the ERP and an increase in ERP dispersion, WOV, and neural activity. With LL-SVCS during 4-6-hour RAP, ERP, WOV, and neural activity returned toward baseline levels (all P <.05, compared with the third-hour RAP values). CONCLUSIONS RAP not only induces atrial electrical remodeling but also promotes autonomic remodeling. These 2 remodeling processes may form a vicious cycle and each may perpetuate the other. These findings may help to explain how AF maintains itself in its very early stage. LL-SVCS both reversed remodeling processes and can potentially break the vicious cycle of "AF begets AF" in the first few hours of AF.
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Affiliation(s)
- Lilei Yu
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
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SHA YONG, SCHERLAG BENJAMINJ, YU LILEI, SHENG XIA, JACKMAN WARRENM, LAZZARA RALPH, PO SUNNYS. Low-Level Right Vagal Stimulation: Anticholinergic and Antiadrenergic Effects. J Cardiovasc Electrophysiol 2011; 22:1147-53. [DOI: 10.1111/j.1540-8167.2011.02070.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Scherlag BJ, Nakagawa H, Jackman WM, Lazzara R, Po SS. Non-pharmacological, non-ablative approaches for the treatment of atrial fibrillation: experimental evidence and potential clinical implications. J Cardiovasc Transl Res 2010; 4:35-41. [PMID: 21057908 DOI: 10.1007/s12265-010-9231-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2010] [Accepted: 10/19/2010] [Indexed: 12/22/2022]
Abstract
In this review, we initially covered the basic and clinical reports that provided the prevalent concepts underlying the mechanisms for atrial fibrillation (AF). The clinical evolution of catheter ablation and its eventual application to AF has also been detailed. A critique of the results based on a review of the literature has shown that either or both drugs or catheter ablation therapy for preventing AF recurrences have significant limitations and even serious complications. Finally, we have presented recent experimental studies which suggest that an alternative approach to reducing AF inducibility can be achieved with low-level autonomic nerve stimulation. Specifically, electrical stimulation of the vago-sympathetic trunks, at levels well below that which slows the heart rate can significantly increase AF thresholds and suppress AF inducibility. Further studies will determine if this new method can be used as an effective means of treating some forms of clinical AF.
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Affiliation(s)
- Benjamin J Scherlag
- Heart Rhythm Institute, University of Oklahoma Health Sciences Center, 1200 Everett Drive, Rm 6E103, Oklahoma City, OK 73104, USA.
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YU LILEI, SCHERLAG BENJAMINJ, LI SHUYAN, SHENG XIA, LU ZHIBING, NAKAGAWA HIROSHI, ZHANG YING, JACKMAN WARRENM, LAZZARA RALPH, JIANG HONG, PO SUNNYS. Low-Level Vagosympathetic Nerve Stimulation Inhibits Atrial Fibrillation Inducibility: Direct Evidence by Neural Recordings from Intrinsic Cardiac Ganglia. J Cardiovasc Electrophysiol 2010; 22:455-63. [DOI: 10.1111/j.1540-8167.2010.01908.x] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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LOMUSCIO ALBERTO, BELLETTI SEBASTIANO, BATTEZZATI PIERMARIA, LOMBARDI FEDERICO. Efficacy of Acupuncture in Preventing Atrial Fibrillation Recurrences After Electrical Cardioversion. J Cardiovasc Electrophysiol 2010; 22:241-7. [DOI: 10.1111/j.1540-8167.2010.01878.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Abstract
The development of catheter ablation for paroxysmal atrial fibrillation (AF) has evolved rapidly over the last 10 years from an experimental unproven procedure to a commonly performed ablation therapy in many major hospitals. The pulmonary vein (PV) and left atrium were discovered to be critical in the initiation and perpetuation of AF. With a better understanding of the AF mechanisms and more experience from the ablation follow-up, we have seen the ablation technique change from PV focal ablation to empirical circumferential isolation of all four PVs. In addition, the technological aid obtained from 3D electroanatomic mapping systems has further improved the safety and long-term efficacy and minimized the procedural difficulty. Recently, the atrial substrate analysis of the high-frequency and fractionated electrograms has further afforded the improvement in the outcome of more complex arrhythmias. Therefore, in this article, we will review the recent evidence and advancements in the mechanisms of AF and catheter ablation, and highlight the unsolved issues regarding future perspectives for paroxysmal AF.
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Affiliation(s)
- Li-Wei Lo
- Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
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Abstract
Background—
We used high-frequency stimulation delivered during the refractory period of the atrium and pulmonary veins (PVs) to induce focal firing and atrial fibrillation (AF). This study was designed to demonstrate that bilateral low-level vagosympathetic nerve stimulation (LL-VNS) could suppress high-frequency stimulation-induced focal AF at atrial and PV sites.
Methods and Results—
In 23 dogs anesthetized with Na-pentobarbital, electrodes in the vagosympathetic trunks allowed LL-VNS at 1 V below that which slowed the sinus rate or atrioventricular conduction. Multielectrode catheters were fixed at the right and left superior and inferior PVs and both atrial appendages. LL-VNS continued for 3 hours. At the end of each hour, the high-frequency stimulation algorithm consisting of a 40-ms train of stimuli (200 Hz; stimulus duration, 0.1 to 1.0 ms) was delivered 2 ms after the atrial pacing stimulus during the refractory period at each PV and atrial appendages site. The lowest voltage of high-frequency stimulation that induced AF was defined as the AF threshold. Five dogs without LL-VNS served as sham controls. Six dogs underwent LL-VNS after transection of bilateral vagosympathetic trunks. LL-VNS induced a progressive increase in AF threshold at all PV and atrial appendages sites, particularly significant (
P
<0.05) at the right superior PV, right inferior PV, left superior PV, and right atrial appendage. Bilateral vagosympathetic transection did not significantly alter the previous findings, and the 5 sham control dogs did not show changes in AF threshold at any site over a period of 3 hours.
Conclusions—
LL-VNS may prevent episodic AF caused by rapid PV and non-PV firing.
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Affiliation(s)
- Shuyan Li
- From the Department of Medicine and Heart Rhythm Institute (B.J.S., L.Y., X.S., Z.A., U.D., M.G., S.S.P.) and School of Public Health (Y.Z.), University of Oklahoma Health Sciences Center, Oklahoma City, Okla; and the Department of Cardiology (S.L.), the Second Hospital of Jilin University, Jilin, China
| | - Benjamin J. Scherlag
- From the Department of Medicine and Heart Rhythm Institute (B.J.S., L.Y., X.S., Z.A., U.D., M.G., S.S.P.) and School of Public Health (Y.Z.), University of Oklahoma Health Sciences Center, Oklahoma City, Okla; and the Department of Cardiology (S.L.), the Second Hospital of Jilin University, Jilin, China
| | - Lilei Yu
- From the Department of Medicine and Heart Rhythm Institute (B.J.S., L.Y., X.S., Z.A., U.D., M.G., S.S.P.) and School of Public Health (Y.Z.), University of Oklahoma Health Sciences Center, Oklahoma City, Okla; and the Department of Cardiology (S.L.), the Second Hospital of Jilin University, Jilin, China
| | - Xia Sheng
- From the Department of Medicine and Heart Rhythm Institute (B.J.S., L.Y., X.S., Z.A., U.D., M.G., S.S.P.) and School of Public Health (Y.Z.), University of Oklahoma Health Sciences Center, Oklahoma City, Okla; and the Department of Cardiology (S.L.), the Second Hospital of Jilin University, Jilin, China
| | - Ying Zhang
- From the Department of Medicine and Heart Rhythm Institute (B.J.S., L.Y., X.S., Z.A., U.D., M.G., S.S.P.) and School of Public Health (Y.Z.), University of Oklahoma Health Sciences Center, Oklahoma City, Okla; and the Department of Cardiology (S.L.), the Second Hospital of Jilin University, Jilin, China
| | - Reza Ali
- From the Department of Medicine and Heart Rhythm Institute (B.J.S., L.Y., X.S., Z.A., U.D., M.G., S.S.P.) and School of Public Health (Y.Z.), University of Oklahoma Health Sciences Center, Oklahoma City, Okla; and the Department of Cardiology (S.L.), the Second Hospital of Jilin University, Jilin, China
| | - Yumei Dong
- From the Department of Medicine and Heart Rhythm Institute (B.J.S., L.Y., X.S., Z.A., U.D., M.G., S.S.P.) and School of Public Health (Y.Z.), University of Oklahoma Health Sciences Center, Oklahoma City, Okla; and the Department of Cardiology (S.L.), the Second Hospital of Jilin University, Jilin, China
| | - Muhammad Ghias
- From the Department of Medicine and Heart Rhythm Institute (B.J.S., L.Y., X.S., Z.A., U.D., M.G., S.S.P.) and School of Public Health (Y.Z.), University of Oklahoma Health Sciences Center, Oklahoma City, Okla; and the Department of Cardiology (S.L.), the Second Hospital of Jilin University, Jilin, China
| | - Sunny S. Po
- From the Department of Medicine and Heart Rhythm Institute (B.J.S., L.Y., X.S., Z.A., U.D., M.G., S.S.P.) and School of Public Health (Y.Z.), University of Oklahoma Health Sciences Center, Oklahoma City, Okla; and the Department of Cardiology (S.L.), the Second Hospital of Jilin University, Jilin, China
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Abstract
The autonomic nervous system has a crucial role in the genesis, maintenance and abruption of atrial fibrillation. The substrate and trigger mechanism of atrial fibrillation can be influenced by the changing autonomic tone. The authors summarize the current knowledge on the relationship between autonomic nervous system and atrial fibrillation. The special neuroanatomical status and the role of autonomic reflexes and baroreflex in the initiation, maintenance, and termination of arrhythmia are reviewed. Furthermore, the mechanism and consequences of autonomic effect of the curative radiofrequency catheter ablation of pulmonary vein with atrial vagal neuroablation are discussed. At the end we also summarize the pharmacologic therapy of atrial fibrillation. Classification of atrial fibrillation, as either vagal or adrenergic, has only limited impact on current management.
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Affiliation(s)
- István Lorincz
- Debreceni Egyetem, Orvos- és Egészségtudományi Centrum, Altalános Orvostudományi Kar Belgyógyászati Intézet, I. Belgyógyászati Klinika, Sürgosségi Orvostan Tanszék, Debrecen Nagyerdei krt. 98. Pf. 19. 4032.
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Chang SH, Chen YC, Chiang SJ, Higa S, Cheng CC, Chen YJ, Chen SA. Increased Ca(2+) sparks and sarcoplasmic reticulum Ca(2+) stores potentially determine the spontaneous activity of pulmonary vein cardiomyocytes. Life Sci 2008; 83:284-92. [PMID: 18639558 DOI: 10.1016/j.lfs.2008.06.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2008] [Revised: 05/31/2008] [Accepted: 06/18/2008] [Indexed: 10/21/2022]
Abstract
Pulmonary veins (PVs) contain cardiomyocytes with spontaneous activity that may be responsible for PV arrhythmia. Abnormal Ca(2+) regulation is known to contribute to PV arrhythmogenesis. The purpose of this study was to investigate whether PV cardiomyocytes with spontaneous activity have different intracellular Ca(2+) ([Ca(2+)](i)) transients, Ca(2+) sparks and responses to isoproterenol and ryanodine receptor modulators (magnesium and FK506) than do PV cardiomyocytes without spontaneous activity and left atrial (LA) cardiomyocytes. Through fluorescence and confocal microscopy, we evaluated the [Ca(2+)](i) transients and Ca(2+) sparks in isolated rabbit PV and LA cardiomyocytes. PV cardiomyocytes with spontaneous activity had larger [Ca(2+)](i) transients and sarcoplasmic reticulum (SR) Ca(2+) stores than PV cardiomyocytes without spontaneous activity or LA cardiomyocytes. PV cardiomyocytes with spontaneous activity also had a higher incidence and frequency of Ca(2+) sparks, and had Ca(2+) sparks with larger amplitudes than other cardiomyocytes. Magnesium (5.4 mM) reduced the [Ca(2+)](i) transient amplitude and beating rate in PV cardiomyocytes with spontaneous activity. However, in contrast with other cardiomyocytes, low doses (1.8 mM) of magnesium did not reduce the [Ca(2+)](i) transients amplitude in PV cardiomyocytes with spontaneous activity. FK506 (1 microM) diminished the SR Ca(2+) stores in PV cardiomyocytes with spontaneous activity to a lesser extent than that in other cardiomyocytes. Isoproterenol (10 nM) increased the [Ca(2+)](i) transient amplitude to a lesser extent in LA cardiomyocytes than in PV cardiomyocytes with or without spontaneous activity. In conclusion, our results suggest that enhanced [Ca(2+)](i) transients, increased Ca(2+) sparks and SR Ca(2+) stores may contribute to the spontaneous activity of PV cardiomyocytes.
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Affiliation(s)
- Sheng-Hsiung Chang
- Division of Cardiovascular Medicine, Mackay Memorial Hospital, Taipei, Taiwan
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33
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Lo LW, Chen YC, Chen YJ, Wongcharoen W, Lin CI, Chen SA. Calmodulin kinase II inhibition prevents arrhythmic activity induced by alpha and beta adrenergic agonists in rabbit pulmonary veins. Eur J Pharmacol 2007; 571:197-208. [PMID: 17612522 DOI: 10.1016/j.ejphar.2007.05.066] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2007] [Revised: 05/28/2007] [Accepted: 05/30/2007] [Indexed: 11/28/2022]
Abstract
The autonomic nervous system and calcium regulation play important roles in the pathophysiology of atrial fibrillation. Calmodulin regulates the calcium homeostasis and may mediate the proarrhythmic effects of autonomic nervous agents. The purpose of this study was to compare the effects of beta- and alpha-adrenoceptor agonists on the pulmonary vein electrical activity and evaluate whether calmodulin kinase II inhibitors may change the effects of the adrenoceptor agonists on the pulmonary vein arrhythmogenesis. Conventional microelectrodes were used to record the action potentials in isolated rabbit pulmonary vein tissue specimens before and after the administration of isoproterenol, phenylephrine and KN-93 (a calmodulin kinase II inhibitor). In the tissue preparation, isoproterenol (0, 0.1, 3 microM) increased the beating rates (1.5+/-0.2, 1.6+/-0.2, 2.3+/-0.3 Hz, n=10, P<0.001) with the genesis of early afterdepolarizations (EADs, 0%, 40%, 50%, P<0.05) and increased the amplitude of the delayed afterdepolarizations (DADs, 0.6+/-0.3, 1.7+/-0.4, 3.9+/-1.0 mV, P<0.05). Phenylephrine (0, 1, 10 microM) also increased the beating rates (1.4+/-0.2, 1.6+/-0.2, 1.9+/-0.2 Hz, n=12, P<0.001), incidence of EADs (0%, 8%, 50%, P<0.05) and amplitude of the DADs (0.4+/-0.2, 1.2+/-0.4, 2.6+/-0.8 mV, P<0.05). KN-93 did not change the pulmonary vein beating rates or action potential duration. However, in the presence of KN-93 (1 microM), isoproterenol (3 microM) and phenylephrine (10 microM) did not induce any EADs or DADs in the pulmonary veins. In conclusion, calmodulin kinase II inhibition may prevent adrenergic induced pulmonary vein arrhythmogenesis.
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Affiliation(s)
- Li-Wei Lo
- National Yang-Ming University, School of Medicine, Division of Cardiology and Cardiovascular Research Center, Taipei Veterans General Hospital, Taiwan
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Horikawa-Tanami T, Hirao K, Furukawa T, Isobe M. Mechanism of the Conversion of a Pulmonary Vein Tachycardia to Atrial Fibrillation in Normal Canine Hearts: Role of Autonomic Nerve Stimulation. J Cardiovasc Electrophysiol 2007; 18:534-41. [PMID: 17313531 DOI: 10.1111/j.1540-8167.2007.00772.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
INTRODUCTION The role of the autonomic nervous system in inducing pulmonary vein (PV)-triggered atrial fibrillation (AF) and the termination mechanism of the AF are unknown. The purpose of this study was to elucidate the mechanism of the conversion of a tachycardia within a PV into AF under autonomic stimulation and the termination mechanism of the AF in normal canine hearts. METHODS AND RESULTS In open-chest dogs, the electrophysiologic parameters were measured under vagal stimulation (VS) or an isoproterenol administration. The effects of the VS or isoproterenol on the PV tachycardias (PVTs), which were created by burst pacing from a PV or the application of aconitine onto the PV, were evaluated. Pilsicainide, a Na channel blocker, was administered during the induced AF. VS and isoproterenol shortened the atrial and PV effective refractory periods. In the pacing model, the VS converted the PV rapid activations into sustained AF in 9 of 12 dogs during pacing cycle lengths < or = 120 msec, but the isoproterenol did not cause any sustained AF. In the aconitine model, the VS increased the rate of the aconitine-induced PVTs and transformed them into sustained AF in all 14 dogs, whereas the isoproterenol did not induce AF, and decreased the PVT rate. In all 14 dogs the sustained AF was terminated by pilsicainide, which had suppressive effects on the PVT as well as atria and PV-atrial junction. CONCLUSIONS These findings indicate that the vagal effects affecting the PVT and atria facilitate the onset and maintenance of PV-triggered AF in normal canine hearts.
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Affiliation(s)
- Tomoe Horikawa-Tanami
- Department of Cardiovascular Medicine, Tokyo Medical and Dental University, Tokyo, Japan
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Kuo JY, Chen SA. Is Vagal Denervation a Good Alternative or Just Adjunctive to Pulmonary Vein Isolation in Catheter Ablation of Atrial Fibrillation?⁎⁎Editorials published in the Journal of the American College of Cardiologyreflect the views of the authors and do not necessarily represent the views of JACCor the American College of Cardiology. J Am Coll Cardiol 2007; 49:1349-51. [PMID: 17394968 DOI: 10.1016/j.jacc.2007.01.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Sweeney CM, Jones JFX, Bund SJ. Adrenoceptor and cholinoceptor modulation of rat pulmonary vein cardiac muscle contractility. Vascul Pharmacol 2007; 46:166-70. [PMID: 17113830 DOI: 10.1016/j.vph.2006.09.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2006] [Revised: 08/22/2006] [Accepted: 09/18/2006] [Indexed: 11/15/2022]
Abstract
Cardiac muscle extends into mammalian pulmonary veins for variable distances according to species. This study has addressed the autonomic control of electrically paced cardiac muscle of the pulmonary vein of the rat. Contractile responses of Wistar rat pulmonary veins were investigated under isometric conditions in vitro. Vessels were electrically paced at 1 Hz (10 V, 1 ms pulse width). Acetylcholine (ACh, 1 nM-10 microM) attenuated the contractile response (maximum inhibition at 1 microM, 41+/-15%, mean+/-SD). The attenuation was inhibited by atropine (p<0.05) and partially inhibited (7+/-4%, mean+/-SD, p<0.01) by removal of the endothelium. Noradrenaline (NA, 1 nM-10 microM) augmented the cardiac muscle contractility in a fashion partially inhibited by atenolol; augmentation at 10 microM was reduced from 169+/-9% (n=6) to 135+/-9% (n=5), (p<0.05). The ability of ACh to attenuate the contractile responses was unaffected by the presence of NA. In conclusion, ACh has a muscarinic receptor-mediated negative inotropic effect upon the cardiac muscle of the pulmonary vein of the rat mediated in part by the endothelium. The cardiac muscle expresses a positive inotropic response to NA partly mediated by beta1-adrenoceptors that can be antagonised by ACh. Therefore, pulmonary vein cardiac muscle function is modulated by competing autonomic influences which may be of significance to the generation of atrial fibrillation events.
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Affiliation(s)
- Catherine M Sweeney
- UCD School of Medicine and Medical Science, University College Dublin, Earlsfort Terrace, Dublin 2, Ireland
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Huang CX, Hu CL, Li YB. Atrial fibrillation may be a vascular disease: the role of the pulmonary vein. Med Hypotheses 2006; 68:629-34. [PMID: 17011134 DOI: 10.1016/j.mehy.2006.07.048] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2006] [Revised: 07/07/2006] [Accepted: 07/11/2006] [Indexed: 11/19/2022]
Abstract
Recent years have seen an enormous amount of experimental and clinical research into role of the pulmonary veins (PVs) in atrial fibrillation (AF). The PVs contain cardiomyocytes with easily inducible arrhythmogenic activity due to the enhanced automaticity, induction of triggered activity, and genesis of microreentrant circuits. The enhanced automaticity, induced triggered activity, either alone or in combination with the reentrant mechanisms, may play a role in the initiation of PVs AF. Detailed mapping studies suggest that reentry within the PVs is most likely responsible for their arrhythmogenicity. There is no doubt that the PVs represent the most important source of arrhythmogenic activity in patients with paroxysmal AF. In AF patients with risk factors for development of AF, the presence of the pathological situation is important in enhancing the PV arrhythmogenic activity. Coronary sinus or superior vena cava may also be a source of rapid repetitive electrical activity during AF. Thus, AF should be considered a kind of vascular disease. Moreover, in patients with paroxysmal AF originating from the PVs, a wide spectrum of atrial arrhythmias may coexist, including paroxysms of atrial premature, tachycardia, flutter and fibrillation. This kind of arrhythmias should be named as PV atrial arrhythmias. These new views will help understand the mechanism, diagnosis and treatment method for AF.
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Affiliation(s)
- Cong Xin Huang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, PR China.
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Chen J, Wasmund SL, Hamdan MH. Back to the Future: The Role of the Autonomic Nervous System in Atrial Fibrillation. Pacing and Clinical Electrophysiology 2006; 29:413-21. [PMID: 16650271 DOI: 10.1111/j.1540-8159.2006.00362.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The purpose of this manuscript is to review the current literature regarding the role of the autonomic nervous system (ANS) in atrial fibrillation (AF). We will be reviewing its effect on initiation, maintenance, and termination of AF, with emphasis on the role of baroreflex gain (BRG) and autonomic reflexes in the maintenance of this arrhythmia. While it is generally accepted that the ANS plays an important role in AF, the extent of that role remains controversial. Much of the controversy could be explained by the time frame during which the autonomic measurements were made, the differences in patient population, and possibly the differential effect of the autonomic changes on the trigger versus the substrate. While vagal stimulation results in shortening of the atrial effective refractory period and increased dispersion of refractoriness, its effect on the "trigger" might be antiarrhythmic. During AF, cardiac filling pressure increases while arterial blood pressure decreases sending conflicting messages to the medulla. The acute effect is an increase in sympathetic activity to ensure adequate hemodynamic stability. On the other hand, the long-term effects might be impairment in the cardiopulmonary BRG and changes that accentuate the presence of AF. While radiofrequency ablation has provided us with a unique insight into the role of possible denervation in AF suppression, the exact mechanisms involved are far from being completely understood. Today, in an era where great technological advances have occurred, our need to understand the role of the ANS in AF is greater than ever.
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Affiliation(s)
- Jay Chen
- Department of Internal Medicine, Division of Cardiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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Hsieh MH, Tai CT, Lee SH, Lin YK, Tsao HM, Chang SL, Lin YJ, Wongchaoen W, Lee KT, Chen SA. The Different Mechanisms Between Late and Very Late Recurrences of Atrial Fibrillation in Patients Undergoing a Repeated Catheter Ablation. J Cardiovasc Electrophysiol 2006; 17:231-5. [PMID: 16643390 DOI: 10.1111/j.1540-8167.2005.00323.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
INTRODUCTION The mechanisms of late (<1 year after the ablation) and very late (>1 year after the ablation) recurrences of paroxysmal atrial fibrillation (AF) after catheter ablation have not been reported. METHODS AND RESULTS Fifty consecutive patients undergoing a repeated electrophysiologic study to investigate the recurrence of paroxysmal AF after the first ablation were included. Group 1 consisted of 12 patients with very late (26 +/- 13 months) and group 2 consisted of 38 patients with late (3 +/- 3 months) recurrence of paroxysmal AF. In the baseline study, group 1 had a lower incidence of AF foci from the pulmonary veins (PVs) (67% vs 92%, P = 0.048) and a higher incidence of AF foci from the right atrium (50% vs 13%, P = 0.014) than group 2. In the repeated study, group 1 had a higher incidence of AF foci from the right atrium (67% vs 3%, P < 0.001) and a lower incidence of AF foci from the left atrium (50% vs 97%, P < 0.001), including a lower incidence of AF foci from the PVs (50% vs 79%, P = 0.07) and from the left atrial free wall (0% vs 29%, P = 0.046) than group 2. Furthermore, most of these AF foci (64% of group 1, 65% of group 2) were from the previously targeted foci. CONCLUSION The right atrial foci played an important role in the very late recurrence of AF, whereas the left atrial foci (the majority were PVs) were the major origin of the late recurrence of AF after the catheter ablation of paroxysmal AF.
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Affiliation(s)
- Ming-Hsiung Hsieh
- Division of Cardiovascular Medicine, Department of Medicine, Taipei Medical University School of Medicine, and Taipei Wan-Fang Hospital, Taipei, Taiwan
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Abstract
Pulmonary veins were found to be important foci for the genesis and maintenance of atrial fibrillation. Morphological studies have demonstrated the presence of complex anatomic structures and different types of cardiomyocytes in pulmonary veins. Numerous studies have suggested that the combination of reentrant and nonreentrant mechanisms (automaticity and triggered activity) are the underlying arrhythmogenic mechanisms of atrial fibrillation initiation from the pulmonary veins. Electropharmacological studies further indicated that pulmonary veins contained distinct arrhythmogenic activity. Several experimental models have been used to study the pulmonary vein electrical activity and demonstrate the precipitating factors for enhancing the pulmonary vein arrhythmogenic activity. The aim of this review article is to provide a critical overview of the current understanding of the basic and clinical electrophysiology of pulmonary veins and to underscore the importance of future research in this field.
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Affiliation(s)
- Yi-Jen Chen
- National Yang-Ming University, School of Medicine, Division of Cardiology and Cardiovascular Research Center, Veterans General Hospital-Taipei, Taipei, Taiwan
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Lee SH, Tai CT, Hsieh MH, Tsao HM, Lin YJ, Chang SL, Huang JL, Lee KT, Chen YJ, Cheng JJ, Chen SA. Predictors of Non-Pulmonary Vein Ectopic Beats Initiating Paroxysmal Atrial Fibrillation. J Am Coll Cardiol 2005; 46:1054-9. [PMID: 16168291 DOI: 10.1016/j.jacc.2005.06.016] [Citation(s) in RCA: 168] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2005] [Revised: 05/23/2005] [Accepted: 05/31/2005] [Indexed: 10/25/2022]
Abstract
OBJECTIVES The purpose of this study was to investigate the predictor of non-pulmonary vein (PV) ectopic beats initiating paroxysmal atrial fibrillation (PAF). BACKGROUND Non-PV ectopic beats can initiate PAF in some patients and play an important role in the recurrence of PAF after PV isolation. Information on the predictors of non-PV ectopic beats initiating PAF is unknown. METHODS This study included 293 patients (215 men and 78 women, age 60 +/- 14 years) with clinically documented drug-refractory PAF. Of the 94 patients with non-PV ectopic beats initiating PAF, 38 (40%) patients had superior vena cava (SVC) ectopic beats and 32 (34%) had left atrial posterior free wall (LAPFW) ectopic beats. RESULTS In a univariate analysis, only female gender was related to the presence of non-PV (p = 0.016) and SVC ectopic beats (p = 0.012). Right atrial enlargement (p = 0.005) and left atrial enlargement (p < 0.001) were related to the presence of LAPFW ectopic beats. In a multivariate analysis, female gender (p = 0.043; odds ratio 2.00, 95% confidence interval [CI] 1.02 to 3.92) and left atrial enlargement (p = 0.007; odds ratio 2.34, 95% CI 1.27 to 4.32) could predict the presence of non-PV ectopic beats. Subgroup analysis showed that female gender could predict the presence of SVC ectopic beats (p = 0.039; odds ratio 2.14, 95% CI 1.04 to 4.43). In contrast, left atrial enlargement could predict the presence of LAPFW ectopic beats (p = 0.002; odds ratio 3.89, 95% CI 1.62 to 9.38). CONCLUSIONS The location of non-PV ectopic beats initiating PAF can be predicted by both gender and left atrial enlargement.
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Affiliation(s)
- Shih-Huang Lee
- Department of Medicine, National Yang-Ming University, Taipei, Taiwan.
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Mainardi LT, Corino VDA, Lombardi L, Tondo C, Mantica M, Lombardi F, Cerutti S. Assessment of the dynamics of atrial signals and local atrial period series during atrial fibrillation: effects of isoproterenol administration. Biomed Eng Online 2004; 3:37. [PMID: 15500687 PMCID: PMC529297 DOI: 10.1186/1475-925x-3-37] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2004] [Accepted: 10/22/2004] [Indexed: 11/30/2022] Open
Abstract
Background The autonomic nervous system (ANS) plays an important role in the genesis and maintenance of atrial fibrillation (AF), but quantification of its electrophysiologic effects is extremely complex and difficult. Aim of the study was to evaluate the capability of linear and non-linear indexes to capture the fine changing dynamics of atrial signals and local atrial period (LAP) series during adrenergic activation induced by isoproterenol (a sympathomimetic drug) infusion. Methods Nine patients with paroxysmal or persistent AF (aged 60 ± 6) underwent electrophysiological study in which isoproterenol was administered to patients. Atrial electrograms were acquired during i) sinus rhythm (SR); ii) sinus rhythm during isoproterenol (SRISO) administration; iii) atrial fibrillation (AF) and iv) atrial fibrillation during isoproterenol (AFISO) administration. The level of organization between two electrograms was assessed by the synchronization index (S), whereas the degree of recurrence of a pattern in a signal was defined by the regularity index (R). In addition, the level of predictability (LP) and regularity of LAP series were computed. Results LAP series analysis shows a reduction of both LP and R index during isoproterenol infusion in SR and AF (RSR = 0.75 ± 0.07 RSRISO = 0.69 ± 0.10, p < 0.0001; RAF = 0.31 ± 0.08 RAFISO = 0.26 ± 0.09, p < 0.0001; LPSR = 99.99 ± 0.001 LPSRISO = 99.97 ± 0.03, p < 0.0001; LPAF = 69.46 ± 21.55 LPAFISO = 55 ± 24.75; p < 0.0001). Electrograms analysis shows R index reductions both in SR (RSR = 0.49 ± 0.08 RSRISO = 0.46 ± 0.09 p < 0.0001) and in AF (RAF = 0.29 ± 0.09 RAFISO = 0.28 ± 0.08 n.s.). Conclusions The proposed parameters succeeded in discriminating the subtle changes due to isoproterenol infusion during both the rhythms especially when considering LAP series analysis. The reduced value of analyzed parameters after isoproterenol administration could reflect an important pro-arrhythmic influence of adrenergic activation on favoring maintenance of AF.
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Affiliation(s)
- Luca T Mainardi
- Department of Biomedical Eng., Polytechnic University of Milan, Via Golgi 39, 20133 Milano Italy
| | - Valentina DA Corino
- Department of Biomedical Eng., Polytechnic University of Milan, Via Golgi 39, 20133 Milano Italy
| | - Leonida Lombardi
- Cardiologia, Dipartimento di Medicina, Chirurgia e Odontoiatria, Osp. San Paolo, Università di Milano, via A. di Rudini 8, 20142 Milan, Italy
| | - Claudio Tondo
- Electrophysiology Laboratory, S Ambrogio Hospital, Milan, Italy
| | - Massimo Mantica
- Electrophysiology Laboratory, S Ambrogio Hospital, Milan, Italy
| | - Federico Lombardi
- Cardiologia, Dipartimento di Medicina, Chirurgia e Odontoiatria, Osp. San Paolo, Università di Milano, via A. di Rudini 8, 20142 Milan, Italy
| | - Sergio Cerutti
- Department of Biomedical Eng., Polytechnic University of Milan, Via Golgi 39, 20133 Milano Italy
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Cummings JE, Gill I, Akhrass R, Dery M, Biblo LA, Quan KJ. Preservation of the anterior fat pad paradoxically decreases the incidence of postoperative atrial fibrillation in humans. J Am Coll Cardiol 2004; 43:994-1000. [PMID: 15028356 DOI: 10.1016/j.jacc.2003.07.055] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2003] [Revised: 07/10/2003] [Accepted: 07/14/2003] [Indexed: 11/22/2022]
Abstract
OBJECTIVES The goal of this study was to determine if parasympathetic nerves in the anterior fat pad (FP) can be stimulated at the time of coronary artery bypass surgery (CABG), and if dissection of this FP decreases the incidence of postoperative atrial fibrillation (AF). BACKGROUND The human anterior epicardial FP contains parasympathetic ganglia and is often dissected during CABG. Changes in parasympathetic tone influence the incidence of AF. METHODS Fifty-five patients undergoing CABG were randomized to anterior FP preservation (group A) or dissection (group B). Nerve stimulation was applied to the FP before and after surgery. Sinus cycle length (CL) was measured during stimulation. The incidence of postoperative AF was recorded. RESULTS Of the 55 patients enrolled, 26 patients were randomized to group A, and 29 patients were randomized to group B. In all of the 55 patients, the FP was identified before initiating cardiopulmonary bypass by CL prolongation with stimulation (865.5 +/- 147.9 ms vs. 957.9 +/- 155.1 ms, baseline vs. stimulation, p < 0.001). In group A, stimulation at the conclusion of surgery increased sinus CL (801.8 +/- 166.4 ms vs. 890.9 +/- 178.2 ms, baseline vs. stimulation, p < 0.001). In group B, repeat stimulation failed to increase sinus CL (853.6 +/- 201.6 ms vs. 841.4 +/- 198.4 ms, baseline vs. stimulation, p = NS). The incidence of postoperative AF in group A (7%) was significantly less than that in group B (37%) (p < 0.01). CONCLUSIONS This is the first study demonstrating that direct stimulation of the human anterior epicardial FP slows sinus CL. This parasympathetic effect is eliminated with FP dissection. Preservation of the human anterior epicardial FP during CABG decreases incidence of postoperative AF.
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Affiliation(s)
- Jennifer E Cummings
- Heart and Vascular Research Center, MetroHealth Campus, Case Western Reserve University, 2500 MetroHealth Drive, Cleveland, OH 44109, USA
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Abstract
Low-level electromagnetic fields (EMFs) have been used to treat various neurologic disorders. In the present study, we applied micro Gauss (microG) levels of EMFs either to the vagosympathetic nerve trunks, dissected in the neck, or across the chest in anesthetized dogs. Based on theoretical and empiric grounds, we compared EMFs (2.87 microG at 0.043 Hz) delivered to the vagosympathetic trunks in an experimental set (n = 5) with a sham control group (n = 6). Over a period of 2 to 3 hours, heart rate decreased after an initial 5-minute EMF exposure. The maximal heart rate changes in the experimental versus control groups was 29% versus 12% (P = 0.03). The voltage applied to the autonomic nerves required to induce atrioventricular (AV) conduction block decreased by 60% in the experimental group versus a 5% increase in the control group (P = 0.005). This effect also lasted 2 to 3 hours. Another EMF setting (amplitude 0.34 microG, frequency 2 kHz) applied for 5 minutes to the vagosympathetic trunks was associated with a significant increase in the occurrence of atrial premature depolarizations (APDs), atrial tachycardia (AT), and atrial fibrillation (AF) in response to autonomic nerve stimulation compared with control states before EMF exposure. No atrial arrhythmias could be induced after propranolol and atropine, even at the highest voltage used to stimulate the autonomic nervous input to the heart (n = 11). Only 2 dogs showed no response to this EMF application. In 3 dogs in whom atrial pacing (cycle length = 250 ms) and autonomic nerve stimulation induced AF, an EMF (2.87 microG at 0.043 Hz) delivered for 35 minutes across the chest suppressed AF for up to 3 to 4 hours, after which the same protocol again induced AF. We conclude that in these preliminary experiments, specific low-level EMFs alter heart rate, AV conduction, and heart rhythm. These effects were mediated through the autonomic nervous system inputs to the heart based on adjunctive effect of autonomic nerve stimulation and the inhibitory action of autonomic blockers.
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Affiliation(s)
- Benjamin J Scherlag
- Cardiac Arrhythmia Research Institute at the University of Oklahoma Medical Center, Oklahoma City, OK 73104, USA.
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Abstract
The basic electrophysiologic studies have proved the arrhythmogenic mechanisms of the pulmonary vein as an atrial fibrillation initiator; the mechanisms include enhanced automaticity, triggered activity, and microreentry from myocardial sleeves inside pulmonary veins. Immunohistology study has proved the conduction characteristics of pulmonary vein myocardium, and further study of ionic currents are important for understanding atrial fibrillation initiation from the pulmonary vein.
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Affiliation(s)
- Shih-Ann Chen
- Division of Cardiology, Veterans General Hospital-Taipei, Taiwan.
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Abstract
BACKGROUND Mechanisms favoring the occurrence of paroxysmal atrial fibrillation (PAF) are complex and poorly defined. This study was designed to analyze dynamic changes in autonomic tone preceding the onset of PAF in a large group of patients. METHODS AND RESULTS Holter tapes from 77 unselected consecutive patients (63 men and 14 women aged 58+/-12 years) with PAF were analyzed. A total of 147 episodes of sustained AF (>30 minutes) were recorded and submitted to time-domain and frequency-domain heart rate variability analyses; 6 periods were studied using repeated measures ANOVA: the 24-hour period, the hour preceding PAF, and the 20 minutes before PAF divided into four 5-minute periods. In the time-domain analyses, a linear decrease in mean RR interval from 925+/-16 to 906+/-16 ms (P<0.0002) was observed before the onset of PAF, together with a significant increase in the standard deviation of NN intervals from 65+/-4 to 70+/-4 ms (P<0.02). In the frequency-domain analyses, a significant increase in high-frequency (HF, HF-NU) components was observed before PAF (P<0.001 and P<0.0001, respectively), together with a progressive decrease in low-frequency components (LF, LF-NU) (P<0.0001 and P<0.004, respectively). The low/high frequency ratio showed a linear increase until 10 minutes before PAF, followed by a sharp decrease immediately before PAF, suggesting a primary increase in adrenergic tone followed by a marked modulation toward vagal predominance. No difference was observed in these heart rate variability changes between patients with "lone" PAF and patients with structural heart disease. CONCLUSIONS The occurrence of PAF greatly depends on variations of the autonomic tone, with a primary increase in adrenergic tone followed by an abrupt shift toward vagal predominance.
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Affiliation(s)
- Marco Bettoni
- Cardiology Unit, Cardiovascular Department, Hôpital de La Tour, Geneva, Switzerland
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Abstract
BACKGROUND The superior vena cava (SVC) has been proved to be a focal point in the initiation of paroxysmal atrial fibrillation. The autonomic nervous system plays an important role in the genesis of atrial fibrillation. However, the arrhythmogenic potentials of SVC and its responses to autonomic agents are not clear. The purpose of this study was to isolate single SVC cardiomyocytes and to investigate their electrophysiological characteristics, as well as the direct effects of autonomic agents. METHODS AND RESULTS Canine SVC cardiomyocytes were isolated by perfusion with digestive enzymes. The action potentials and ionic currents were investigated in single SVC cardiomyocytes using the whole-cell clamp technique. Dissociation of the SVC yielded rod-shaped single cardiomyocytes with (n=74, 51%) or without (n=71, 49%) pacemaker activities. There were similar densities of inward Ca2+, delayed rectifier K+, transient inward, inward rectifier K+, and pacemaker currents between SVC cardiomyocytes with and without pacemaker activity. SVC cardiomyocytes with pacemaker activity have, however, greater transient outward currents than those without pacemaker activity. In SVC cardiomyocytes, acetylcholine (5.5 micromol/L) abolished the spontaneous activities, but isoproterenol (10 nmol/L), atropine (10 micromol/L), and phenylephrine (10 micromol/L) accelerated the spontaneous activity and induced the occurrences of early or delayed afterdepolarizations. CONCLUSIONS These findings suggest that SVC cardiomyocytes have distinct action potentials and ionic current profiles that may be responsible for the arrhythmogenic activity of the SVC.
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Affiliation(s)
- Yi-Jen Chen
- Taipei Medical University, Wan-Fang Hospital, Taipei, Taiwan
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