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Jæger KH, Edwards AG, Giles WR, Tveito A. A computational method for identifying an optimal combination of existing drugs to repair the action potentials of SQT1 ventricular myocytes. PLoS Comput Biol 2021; 17:e1009233. [PMID: 34383746 PMCID: PMC8360568 DOI: 10.1371/journal.pcbi.1009233] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 07/01/2021] [Indexed: 01/26/2023] Open
Abstract
Mutations are known to cause perturbations in essential functional features of integral membrane proteins, including ion channels. Even restricted or point mutations can result in substantially changed properties of ion currents. The additive effect of these alterations for a specific ion channel can result in significantly changed properties of the action potential (AP). Both AP shortening and AP prolongation can result from known mutations, and the consequences can be life-threatening. Here, we present a computational method for identifying new drugs utilizing combinations of existing drugs. Based on the knowledge of theoretical effects of existing drugs on individual ion currents, our aim is to compute optimal combinations that can ‘repair’ the mutant AP waveforms so that the baseline AP-properties are restored. More specifically, we compute optimal, combined, drug concentrations such that the waveforms of the transmembrane potential and the cytosolic calcium concentration of the mutant cardiomyocytes (CMs) becomes as similar as possible to their wild type counterparts after the drug has been applied. In order to demonstrate the utility of this method, we address the question of computing an optimal drug for the short QT syndrome type 1 (SQT1). For the SQT1 mutation N588K, there are available data sets that describe the effect of various drugs on the mutated K+ channel. These published findings are the basis for our computational analysis which can identify optimal compounds in the sense that the AP of the mutant CMs resembles essential biomarkers of the wild type CMs. Using recently developed insights regarding electrophysiological properties among myocytes from different species, we compute optimal drug combinations for hiPSC-CMs, rabbit ventricular CMs and adult human ventricular CMs with the SQT1 mutation. Since the ‘composition’ of ion channels that form the AP is different for the three types of myocytes under consideration, so is the composition of the optimal drug. Poly-pharmacology (using multiple drugs to treat disease) has been proposed for improving cardiac anti-arrhythmic therapy for at least two decades. However, the specific arrhythmia contexts in which polytherapy is likely to be both safe and effective have remained elusive. Type 1 short QT syndrome (SQT1) is a rare form of cardiac arrhythmia that results from mutations to the human Ether-á-go-go Related Gene (hERG) potassium channel. Functionally, these mutations are remarkably consistent in that they permit the channel to open earlier during each heart beat. While hundreds of compounds are known to inhibit hERG channels, the specific effect of SQT1 mutations that allows for early channel opening also limits the ability of most of those compounds to correct SQT1 dysfunction. Here, we have applied a suite of ventricular cardiomyocyte computational models to ask whether polytherapy may offer a more effective therapeutic strategy in SQT1, and if so, what the likely characteristics of that strategy are. Our analyses suggest that simultaneous induction of late sodium current and partial hERG blockade offers a promising strategy. While no activators of late sodium current have been clinically approved, several experimental compounds are available and may provide a basis for interrogating this strategy. The method presented here can be used to compute optimal drug combinations provided that the effect of each drug on every relevant ion channel is known.
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MESH Headings
- Action Potentials/drug effects
- Amino Acid Substitution
- Animals
- Anti-Arrhythmia Agents/administration & dosage
- Arrhythmias, Cardiac/drug therapy
- Arrhythmias, Cardiac/genetics
- Arrhythmias, Cardiac/physiopathology
- Computational Biology
- Drug Combinations
- Drug Design
- Drug Therapy, Combination/methods
- ERG1 Potassium Channel/drug effects
- ERG1 Potassium Channel/genetics
- ERG1 Potassium Channel/physiology
- Heart Conduction System/abnormalities
- Heart Conduction System/physiopathology
- Heart Defects, Congenital/drug therapy
- Heart Defects, Congenital/genetics
- Heart Defects, Congenital/physiopathology
- Humans
- Induced Pluripotent Stem Cells/drug effects
- Induced Pluripotent Stem Cells/physiology
- Models, Cardiovascular
- Mutation, Missense
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/physiology
- Rabbits
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Affiliation(s)
| | - Andrew G. Edwards
- Simula Research Laboratory, Oslo, Norway
- Department of Pharmacology, University of California, Davis, California United States of America
| | - Wayne R. Giles
- Simula Research Laboratory, Oslo, Norway
- Department of Physiology and Pharmacology, Faculty of Medicine, University of Calgary, Calgary, Canada
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2
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Jæger KH, Wall S, Tveito A. Computational prediction of drug response in short QT syndrome type 1 based on measurements of compound effect in stem cell-derived cardiomyocytes. PLoS Comput Biol 2021; 17:e1008089. [PMID: 33591962 PMCID: PMC7909705 DOI: 10.1371/journal.pcbi.1008089] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 02/26/2021] [Accepted: 12/20/2020] [Indexed: 12/20/2022] Open
Abstract
Short QT (SQT) syndrome is a genetic cardiac disorder characterized by an abbreviated QT interval of the patient's electrocardiogram. The syndrome is associated with increased risk of arrhythmia and sudden cardiac death and can arise from a number of ion channel mutations. Cardiomyocytes derived from induced pluripotent stem cells generated from SQT patients (SQT hiPSC-CMs) provide promising platforms for testing pharmacological treatments directly in human cardiac cells exhibiting mutations specific for the syndrome. However, a difficulty is posed by the relative immaturity of hiPSC-CMs, with the possibility that drug effects observed in SQT hiPSC-CMs could be very different from the corresponding drug effect in vivo. In this paper, we apply a multistep computational procedure for translating measured drug effects from these cells to human QT response. This process first detects drug effects on individual ion channels based on measurements of SQT hiPSC-CMs and then uses these results to estimate the drug effects on ventricular action potentials and QT intervals of adult SQT patients. We find that the procedure is able to identify IC50 values in line with measured values for the four drugs quinidine, ivabradine, ajmaline and mexiletine. In addition, the predicted effect of quinidine on the adult QT interval is in good agreement with measured effects of quinidine for adult patients. Consequently, the computational procedure appears to be a useful tool for helping predicting adult drug responses from pure in vitro measurements of patient derived cell lines.
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MESH Headings
- Action Potentials/drug effects
- Adult
- Ajmaline/pharmacology
- Algorithms
- Anti-Arrhythmia Agents/pharmacology
- Arrhythmias, Cardiac/drug therapy
- Arrhythmias, Cardiac/genetics
- Arrhythmias, Cardiac/physiopathology
- Cell Line
- Computational Biology
- Drug Evaluation, Preclinical/methods
- Drug Evaluation, Preclinical/statistics & numerical data
- ERG1 Potassium Channel/genetics
- Electrocardiography
- Heart Conduction System/abnormalities
- Heart Conduction System/physiopathology
- Heart Defects, Congenital/drug therapy
- Heart Defects, Congenital/genetics
- Heart Defects, Congenital/physiopathology
- Humans
- In Vitro Techniques
- Induced Pluripotent Stem Cells/drug effects
- Induced Pluripotent Stem Cells/physiology
- Ivabradine/pharmacology
- Mexiletine/pharmacology
- Models, Cardiovascular
- Mutation
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/physiology
- Quinidine/pharmacology
- Translational Research, Biomedical
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Affiliation(s)
| | | | - Aslak Tveito
- Simula Research Laboratory, Oslo, Norway
- Department of Informatics, University of Oslo, Oslo, Norway
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3
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Boukens BJ, Potse M, Coronel R. Fibrosis and Conduction Abnormalities as Basis for Overlap of Brugada Syndrome and Early Repolarization Syndrome. Int J Mol Sci 2021; 22:1570. [PMID: 33557237 PMCID: PMC7913989 DOI: 10.3390/ijms22041570] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 01/28/2021] [Accepted: 01/29/2021] [Indexed: 12/16/2022] Open
Abstract
Brugada syndrome and early repolarization syndrome are both classified as J-wave syndromes, with a similar mechanism of arrhythmogenesis and with the same basis for genesis of the characteristic electrocardiographic features. The Brugada syndrome is now considered a conduction disorder based on subtle structural abnormalities in the right ventricular outflow tract. Recent evidence suggests structural substrate in patients with the early repolarization syndrome as well. We propose a unifying mechanism based on these structural abnormalities explaining both arrhythmogenesis and the electrocardiographic changes. In addition, we speculate that, with increasing technical advances in imaging techniques and their spatial resolution, these syndromes will be reclassified as structural heart diseases or cardiomyopathies.
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Affiliation(s)
- Bastiaan J. Boukens
- Department of Experimental Cardiology, Amsterdam University Medical Center, Amsterdam Cardiovascular Sciences, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands;
- Department of Medical Biology, Amsterdam University Medical Center, Amsterdam Cardiovascular Sciences, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands
| | - Mark Potse
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université, 33600 Bordeaux, France;
- UMR5251, Institut de Mathématiques de Bordeaux, Université de Bordeaux, 33400 Talence, France
- Carmen Team, INRIA Bordeaux—Sud-Ouest, 33400 Talence, France
| | - Ruben Coronel
- Department of Experimental Cardiology, Amsterdam University Medical Center, Amsterdam Cardiovascular Sciences, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands;
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Rana IA, Afzal W. Accessory Cardiac Conduction Pathway with an Unusual Presentation. J Coll Physicians Surg Pak 2019; 29:S77-S79. [PMID: 31779748 DOI: 10.29271/jcpsp.2019.12.s77] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 11/02/2018] [Accepted: 04/20/2019] [Indexed: 06/10/2023]
Abstract
Pre-excitation syndrome (PES) is a congenital abnormality in which there is conduction through accessory pathway in addition to atrioventricular (AV) node between the atria and the ventricles. Conduction through accessory pathway is without any delay and; hence, results in early excitation of ventricles. This dual connection provides substrate for atrioventricular reciprocating tachycardia (AVRT), a type of supra-ventricular tachycardia. Wolf-Parkinson-White (WPW) syndrome is the commonest form of PES. PES with third degree AV block or complete heart block (CHB) is a rare association. We report here a case of 37-year male with surface ECG findings consistent with PES who presented with syncope. The combination of pre-excitation on ECG with syncope usually draws attention towards tachy-arrhythmias. However, ECG monitoring revealed CHB with intermittent conduction through accessory pathway. It highlights the critical evaluation of PES patients with syncope because therapeutic strategy is entirely different. This case was managed with dual chamber pacemaker implantation instead of accessory pathway ablation.
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Affiliation(s)
- Ikram Ahmed Rana
- Department of Cardiology, Tahir Heart Institute, Chenab Nagar, District Chiniot, Pakistan
| | - Wajeeha Afzal
- Department of Cardiology, Tahir Heart Institute, Chenab Nagar, District Chiniot, Pakistan
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5
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El-Battrawy I, Lan H, Cyganek L, Zhao Z, Li X, Buljubasic F, Lang S, Yücel G, Sattler K, Zimmermann WH, Utikal J, Wieland T, Ravens U, Borggrefe M, Zhou XB, Akin I. Modeling Short QT Syndrome Using Human-Induced Pluripotent Stem Cell-Derived Cardiomyocytes. J Am Heart Assoc 2018; 7:e007394. [PMID: 29574456 PMCID: PMC5907581 DOI: 10.1161/jaha.117.007394] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2017] [Accepted: 01/26/2018] [Indexed: 12/25/2022]
Abstract
BACKGROUND Short QT syndrome (SQTS), a disorder associated with characteristic ECG QT-segment abbreviation, predisposes affected patients to sudden cardiac death. Despite some progress in assessing the organ-level pathophysiology and genetic changes of the disorder, the understanding of the human cellular phenotype and discovering of an optimal therapy has lagged because of a lack of appropriate human cellular models of the disorder. The objective of this study was to establish a cellular model of SQTS using human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). METHODS AND RESULTS This study recruited 1 patient with short QT syndrome type 1 carrying a mutation (N588K) in KCNH2 as well as 2 healthy control subjects. We generated hiPSCs from their skin fibroblasts, and differentiated hiPSCs into cardiomyocytes (hiPSC-CMs) for physiological and pharmacological studies. The hiPSC-CMs from the patient showed increased rapidly activating delayed rectifier potassium channel current (IKr) density and shortened action potential duration compared with healthy control hiPSC-CMs. Furthermore, they demonstrated abnormal calcium transients and rhythmic activities. Carbachol increased the arrhythmic events in SQTS but not in control cells. Gene and protein expression profiling showed increased KCNH2 expression in SQTS cells. Quinidine but not sotalol or metoprolol prolonged the action potential duration and abolished arrhythmic activity induced by carbachol. CONCLUSIONS Patient-specific hiPSC-CMs are able to recapitulate single-cell phenotype features of SQTS and provide novel opportunities to further elucidate the cellular disease mechanism and test drug effects.
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MESH Headings
- Action Potentials/drug effects
- Adult
- Anti-Arrhythmia Agents/pharmacology
- Arrhythmias, Cardiac/drug therapy
- Arrhythmias, Cardiac/genetics
- Arrhythmias, Cardiac/metabolism
- Arrhythmias, Cardiac/physiopathology
- Calcium Signaling
- Case-Control Studies
- Cell Differentiation
- Cell Lineage
- Cells, Cultured
- ERG1 Potassium Channel/genetics
- ERG1 Potassium Channel/metabolism
- Genetic Predisposition to Disease
- Heart Conduction System/abnormalities
- Heart Conduction System/metabolism
- Heart Conduction System/physiopathology
- Heart Defects, Congenital/drug therapy
- Heart Defects, Congenital/genetics
- Heart Defects, Congenital/metabolism
- Heart Defects, Congenital/physiopathology
- Heart Rate
- Humans
- Induced Pluripotent Stem Cells/drug effects
- Induced Pluripotent Stem Cells/metabolism
- Kinetics
- Male
- Mutation, Missense
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/metabolism
- Phenotype
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Affiliation(s)
- Ibrahim El-Battrawy
- First Department of Medicine, Faculty of Medicine, University Medical Centre Mannheim (UMM), University of Heidelberg, Mannheim, Germany
- DZHK (German Center for Cardiovascular Research), Partner Sites, Heidelberg-Mannheim and Göttingen, Mannheim, Germany
| | - Huan Lan
- First Department of Medicine, Faculty of Medicine, University Medical Centre Mannheim (UMM), University of Heidelberg, Mannheim, Germany
- DZHK (German Center for Cardiovascular Research), Partner Sites, Heidelberg-Mannheim and Göttingen, Mannheim, Germany
- Key Laboratory of Medical Electrophysiology of Ministry of Education, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, Sichuan, China
| | - Lukas Cyganek
- DZHK (German Center for Cardiovascular Research), Partner Sites, Heidelberg-Mannheim and Göttingen, Mannheim, Germany
- Stem Cell Unit, Clinic for Cardiology and Pneumology, University Medical Center Göttingen, Germany
| | - Zhihan Zhao
- First Department of Medicine, Faculty of Medicine, University Medical Centre Mannheim (UMM), University of Heidelberg, Mannheim, Germany
- DZHK (German Center for Cardiovascular Research), Partner Sites, Heidelberg-Mannheim and Göttingen, Mannheim, Germany
| | - Xin Li
- First Department of Medicine, Faculty of Medicine, University Medical Centre Mannheim (UMM), University of Heidelberg, Mannheim, Germany
| | - Fanis Buljubasic
- First Department of Medicine, Faculty of Medicine, University Medical Centre Mannheim (UMM), University of Heidelberg, Mannheim, Germany
| | - Siegfried Lang
- First Department of Medicine, Faculty of Medicine, University Medical Centre Mannheim (UMM), University of Heidelberg, Mannheim, Germany
- DZHK (German Center for Cardiovascular Research), Partner Sites, Heidelberg-Mannheim and Göttingen, Mannheim, Germany
| | - Gökhan Yücel
- First Department of Medicine, Faculty of Medicine, University Medical Centre Mannheim (UMM), University of Heidelberg, Mannheim, Germany
- DZHK (German Center for Cardiovascular Research), Partner Sites, Heidelberg-Mannheim and Göttingen, Mannheim, Germany
| | - Katherine Sattler
- First Department of Medicine, Faculty of Medicine, University Medical Centre Mannheim (UMM), University of Heidelberg, Mannheim, Germany
| | - Wolfram-Hubertus Zimmermann
- DZHK (German Center for Cardiovascular Research), Partner Sites, Heidelberg-Mannheim and Göttingen, Mannheim, Germany
- Institute of Pharmacology and Toxicology, University of Göttingen, Germany
| | - Jochen Utikal
- Skin Cancer Unit, German Cancer Research Center (DKFZ), Heidelberg and Department of Dermatology, Venereology and Allergology, University Medical Center Mannheim, University of Heidelberg, Mannheim, Germany
- DZHK (German Center for Cardiovascular Research), Partner Sites, Heidelberg-Mannheim and Göttingen, Mannheim, Germany
| | - Thomas Wieland
- Institute of Experimental and Clinical Pharmacology and Toxicology, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
- DZHK (German Center for Cardiovascular Research), Partner Sites, Heidelberg-Mannheim and Göttingen, Mannheim, Germany
| | - Ursula Ravens
- Institute of Experimental Cardiovascular Medicine, University Heart Centre Freiburg, Bad Krozingen, Freiburg, Germany
| | - Martin Borggrefe
- First Department of Medicine, Faculty of Medicine, University Medical Centre Mannheim (UMM), University of Heidelberg, Mannheim, Germany
- DZHK (German Center for Cardiovascular Research), Partner Sites, Heidelberg-Mannheim and Göttingen, Mannheim, Germany
| | - Xiao-Bo Zhou
- First Department of Medicine, Faculty of Medicine, University Medical Centre Mannheim (UMM), University of Heidelberg, Mannheim, Germany
- DZHK (German Center for Cardiovascular Research), Partner Sites, Heidelberg-Mannheim and Göttingen, Mannheim, Germany
- Key Laboratory of Medical Electrophysiology of Ministry of Education, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, Sichuan, China
| | - Ibrahim Akin
- First Department of Medicine, Faculty of Medicine, University Medical Centre Mannheim (UMM), University of Heidelberg, Mannheim, Germany
- DZHK (German Center for Cardiovascular Research), Partner Sites, Heidelberg-Mannheim and Göttingen, Mannheim, Germany
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Yalcinkaya E, Winnik S, Haegeli L, Brunckhorst C, Duru F. Successful Cryoablation of an Anteroseptal Accessory Pathway Guided by Electroanatomical Activation Mapping. J Invasive Cardiol 2016; 28:E227. [PMID: 27922815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The use of electroanatomical mapping can facilitate the identification of the ideal cryoablation site by providing a three-dimensional map of the earliest activation site. Combined use of the cryoablation technology with electroanatomical mapping can further increase the precision and safety of the procedure by applying test applications at a lower energy level.
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Affiliation(s)
- Emre Yalcinkaya
- Arrhythmia and Electrophysiology Division, University Heart Center, 8091, Zurich, Switzerland.
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7
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Uemura H. Surgical aspects of atrial arrhythmia : Right atrial ablation and anti-arrhythmic surgery in congenital heart disease. Herzschrittmacherther Elektrophysiol 2016; 27:137-42. [PMID: 27225164 DOI: 10.1007/s00399-016-0434-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 04/22/2016] [Indexed: 11/25/2022]
Abstract
BACKGROUND Atrial arrhythmias are frequently described in congenital heart disease. OBJECTIVES To provide a surgical perspective of anti-arrhythmic procedures and strategic approaches. METHODS Discussion of the history of anti-arrhythmic treatments in congenital heart disease. RESULTS Before the advent of the Maze procedure (first published in 1991), surgery mainly focused on patients with Wolff-Parkinson-White syndrome and also on arrhythmias in Ebstein's malformation. Atrial septal defects (ASD) subsequently received more attention, i.e., in terms of atrial arrhythmia in the natural prognosis and the surgically modified course and in terms of surgical versus transcatheter approaches. Based on the background of various atrial arrhythmia mechanisms of ASD, several surgical procedures have been reported, ranging from the bilateral full Maze procedure to simple modification of right atriotomy. The so-called right atrial Maze procedure occupies a special position from the viewpoint of cardiology in acquired heart disease, especially in cases of frequently occurring right heart failure. In hearts with more complex structural abnormalities, a detailed understanding of the conditions to improve overall surgical outcome and develop future "anti-arrhythmic" strategies is necessary. CONCLUSIONS It is important to precisely specify factors in the individual cases, not only morphological diversity but also technical and strategic variations and their consequences. A variety of anti-arrhythmic surgical procedures are currently available. How and when to use which procedure requires professional insight and cautious clinical decision-making.
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Affiliation(s)
- Hideki Uemura
- Consultant Cardiac Surgeon, Royal Brompton Hospital, Sydney Street, SW3 6NP, London, UK.
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8
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Nau JY. [Not Available]. Rev Med Suisse 2016; 12:906-907. [PMID: 27323488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
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9
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Sofosbuvir + amiodarone: bradycardia and conduction disturbances. Prescrire Int 2015; 24:294-5. [PMID: 26788575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Cardiac disorders caused by sofosbuvir are liable to be worsened by concomitant use of one of the many drugs that provoke cardiac arrhythmia.
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10
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Nassal MMJ, Wan X, Laurita KR, Cutler MJ. Atrial SERCA2a Overexpression Has No Affect on Cardiac Alternans but Promotes Arrhythmogenic SR Ca2+ Triggers. PLoS One 2015; 10:e0137359. [PMID: 26352986 PMCID: PMC4564245 DOI: 10.1371/journal.pone.0137359] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Accepted: 08/14/2015] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND Atrial fibrillation (AF) is the most common arrhythmia in humans, yet; treatment has remained sub-optimal due to poor understanding of the underlying mechanisms. Cardiac alternans precede AF episodes, suggesting an important arrhythmia substrate. Recently, we demonstrated ventricular SERCA2a overexpression suppresses cardiac alternans and arrhythmias. Therefore, we hypothesized that atrial SERCA2a overexpression will decrease cardiac alternans and arrhythmias. METHODS Adult rat isolated atrial myocytes where divided into three treatment groups 1) Control, 2) SERCA2a overexpression (Ad.SERCA2a) and 3) SERCA2a inhibition (Thapsigargin, 1μm). Intracellular Ca2+ was measured using Indo-1AM and Ca2+ alternans (Ca-ALT) was induced with a standard ramp pacing protocol. RESULTS As predicted, SR Ca2+ reuptake was enhanced with SERCA2a overexpression (p< 0.05) and reduced with SERCA2a inhibition (p<0.05). Surprisingly, there was no difference in susceptibility to Ca-ALT with either SERCA2a overexpression or inhibition when compared to controls (p = 0.73). In contrast, SERCA2a overexpression resulted in increased premature SR Ca2+ (SCR) release compared to control myocytes (28% and 0%, p < 0.05) and concomitant increase in SR Ca2+ load (p<0.05). Based on these observations we tested in-vivo atrial arrhythmia inducibility in control and Ad.SERCA2a animals using an esophageal atrial burst pacing protocol. There were no inducible atrial arrhythmias in Ad.GFP (n = 4) animals though 20% of Ad.SERCA2a (n = 5) animals had inducible atrial arrhythmias (p = 0.20). CONCLUSIONS Our findings suggest that unlike the ventricle, SERCA2a is not a key regulator of cardiac alternans in the atrium. Importantly, SERCA2a overexpression in atrial myocytes can increase SCR, which may be arrhythmogenic.
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Affiliation(s)
- Michelle M. J. Nassal
- Heart and Vascular Research Center, Case Western Reserve University, Cleveland, OH, United States of America
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH, United States of America
| | - Xiaoping Wan
- Heart and Vascular Research Center, Case Western Reserve University, Cleveland, OH, United States of America
| | - Kenneth R. Laurita
- Heart and Vascular Research Center, Case Western Reserve University, Cleveland, OH, United States of America
| | - Michael J. Cutler
- Heart and Vascular Research Center, Case Western Reserve University, Cleveland, OH, United States of America
- Intermountain Heart Institute, Salt Lake City, Utah, United States of America
- * E-mail:
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11
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Babić Z, Pintarić H, Starčević B, Bulum J, Tomulić V, Giunio L, Vuković I, Steiner R, Stipić H, Šikić J, Zekanović D, Prvulović D, Kozmar D, Miličić D. SEVEN-YEAR TRENDS IN THE CROATIAN PRIMARY PERCUTANEOUS CORONARY INTERVENTION NETWORK. Acta Clin Croat 2015; 54:351-358. [PMID: 26666107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023] Open
Abstract
The authors investigated trends in the Croatian primary Percutaneous Coronary Intervention (pPCI) Network results among three consecutive time intervals (2005-2007, first phase; 2008-2009, second phase; and 2010-2011, third phase). Data on 5650 patients with acute myocardial infarction with ST-elevation (STEMI) transferred or directly admitted and treated with pPCI in 11 Croatian PCI centers during the study period were collected and analyzed. The number of patients with acute STEMI treated with pPCI per year rose continuously during the study period (581 vs. 1272 vs. 1949 patients/year). The patient risk profile worsened during the study period: age (60 vs. 61 vs. 63 years; p<0.01), anterior myocardial wall involvement (43% vs. 44% vs. 51%; p<0.01), shock rate (7% vs. 9% vs. 11%; p<0.05), and percentage of transferred patients (42% vs. 36% vs. 46%; p<0.01). While the door-to-balloon time shortened (108 vs. 98 vs. 75 min; p<0.01), the symptom onset-to-door time increased (130 vs. 175 vs. 195 min; p<0.01), but without statistically significant influence on the total ischemic time. Multivariate log-linear analysis eliminated influence of a higher risk profile on the results of treatment and yielded no statistically significant changes in final TIMI 3 flow (Thrombolysis In Myocardial Infarction 3), in-hospital mortality, and six-month mortality rate, but revealed a significant increase in the rate of angina pectoris (12 vs. 22 vs. 36%; p<0.01) and other major adverse cardiovascular events (MACE; 6 vs. 23 vs. 14%; p<0.01) during follow up. In conclusion, the Croatian pPCI Network continuously ensures very good results of STEMI treatment in this economically less developed European country despite worsening of the risk profile in treated patients and opening of new, less experienced PCI centers. The higher percentage of MACE over time could be explained by changes in the pPCI strategy introduced over time (the culprit lesion only) and higher availability of PCI centers for additional PCI after acute STEMI. However, there is room for improvement, especially in reducing prehospital delay.
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12
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Błaut-Jurkowska J, Olszowska M, Kaźnica-Wiatr M, Podolec P. [Lyme carditis]. Pol Merkur Lekarski 2015; 39:111-115. [PMID: 26319387] [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] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Lyme disease is a multisystem infectious disease caused by the spirochete Borrelia burgdorferi. A steady increase in the number of cases is noticed both in Poland and Europe. Cardiac involvement in the course of borreliosis is relatively rare. It is estimated that it concerns about 0.5-10% of patients with Lyme disease. Cardiac involvement generally occurs in the early phase of illness. The most common manifestation of Lyme carditis are transient conduction abnormality, arrhythmias, myocarditis and pericarditis. The basic method of treatment Lyme carditis are antibiotics. The clinical course is usually benign. In most cases a complete recovery is observed. However, in a small proportion of patients dilated cardiomyopathy may occur. Furthermore, death from Lyme carditis has been reported. Lyme carditis remains a real diagnostic and therapeutic challenge for clinicians. Factors that can make the diagnosis difficult are: atypical clinical picture, negation of tick bite, the absence of erythema migrans, onset of symptoms outside the period of tick activity and negative serological results in the initial stage of the disease.
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Affiliation(s)
- Justyna Błaut-Jurkowska
- Department of Cardiac and Vascular Diseases, Institute of Cardiology, Jagiellonian University Medical College, John Paul II Hospital, Cracow, Poland
| | - Maria Olszowska
- Department of Cardiac and Vascular Diseases, Institute of Cardiology, Jagiellonian University Medical College, John Paul II Hospital, Cracow, Poland
| | - Magdalena Kaźnica-Wiatr
- Department of Cardiac and Vascular Diseases, Institute of Cardiology, Jagiellonian University Medical College, John Paul II Hospital, Cracow, Poland
| | - Piotr Podolec
- Department of Cardiac and Vascular Diseases, Institute of Cardiology, Jagiellonian University Medical College, John Paul II Hospital, Cracow, Poland
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deSouza IS, Peterson AC, Marill KA. Differentiating Types of Wide-Complex Tachycardia to Determine Appropriate Treatment in the Emergency Department. Emerg Med Pract 2015; 17:1-23. [PMID: 26308484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 04/10/2015] [Indexed: 06/04/2023]
Abstract
Wide-complex tachycardia is a rare disease entity among patients presenting to the emergency department. However, due to its potential life-threatening nature, emergency clinicians must know how to assess and manage this condition. Wide-complex tachycardia encompasses a range of cardiac dysrhythmias, some of which can be difficult to distinguish and may require specific treatment approaches. This review summarizes the etiology and pathophysiology of wide-complex tachycardia, describes the differential diagnosis, and presents an evidence-based approach to identification of the different types of tachycardias through the use of a thorough history and physical examination, vagal maneuvers, electrocardiography, and adenosine. The treatment options and disposition for patients with various wide-complex tachycardias are also discussed, with attention to special circumstances and select controversial/contemporary topics.
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Affiliation(s)
- Ian S deSouza
- Associate Professor, Department of Emergency Medicine, SUNY Downstate Medicine Center/Kings County Hospital Center, Brooklyn, NY
| | - Alanna C Peterson
- Department of Emergency Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | - Keith A Marill
- Research Faculty, Department of Emergency Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA
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Evrard P, Deprez N. [Left ventricular non compaction: A poorly known cardiomyopathy]. Rev Med Liege 2015; 70:351-354. [PMID: 26376559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Left ventricular non compaction is a rare congenital cardiomyopathy. It is characterised by a thin compacted epicardial layer, prominent trabeculations and deep recesses that communicate with the left ventricular cavity. This condition may lead to chronic heart failure, life threatening ventricular arrhythmias and systemic embolic events.
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Zimik S, Vandersickel N, Nayak AR, Panfilov AV, Pandit R. A Comparative Study of Early Afterdepolarization-Mediated Fibrillation in Two Mathematical Models for Human Ventricular Cells. PLoS One 2015; 10:e0130632. [PMID: 26125185 PMCID: PMC4488347 DOI: 10.1371/journal.pone.0130632] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [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: 03/13/2015] [Accepted: 05/21/2015] [Indexed: 02/06/2023] Open
Abstract
Early afterdepolarizations (EADs), which are abnormal oscillations of the membrane potential at the plateau phase of an action potential, are implicated in the development of cardiac arrhythmias like Torsade de Pointes. We carry out extensive numerical simulations of the TP06 and ORd mathematical models for human ventricular cells with EADs. We investigate the different regimes in both these models, namely, the parameter regimes where they exhibit (1) a normal action potential (AP) with no EADs, (2) an AP with EADs, and (3) an AP with EADs that does not go back to the resting potential. We also study the dependence of EADs on the rate of at which we pace a cell, with the specific goal of elucidating EADs that are induced by slow or fast rate pacing. In our simulations in two- and three-dimensional domains, in the presence of EADs, we find the following wave types: (A) waves driven by the fast sodium current and the L-type calcium current (Na-Ca-mediated waves); (B) waves driven only by the L-type calcium current (Ca-mediated waves); (C) phase waves, which are pseudo-travelling waves. Furthermore, we compare the wave patterns of the various wave-types (Na-Ca-mediated, Ca-mediated, and phase waves) in both these models. We find that the two models produce qualitatively similar results in terms of exhibiting Na-Ca-mediated wave patterns that are more chaotic than those for the Ca-mediated and phase waves. However, there are quantitative differences in the wave patterns of each wave type. The Na-Ca-mediated waves in the ORd model show short-lived spirals but the TP06 model does not. The TP06 model supports more Ca-mediated spirals than those in the ORd model, and the TP06 model exhibits more phase-wave patterns than does the ORd model.
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Affiliation(s)
- Soling Zimik
- Department of Physics, Centre for Condensed Matter Theory, Indian Institute of Science, Bangalore, Karnataka, India
| | - Nele Vandersickel
- Department of Physics and Astronomy, Ghent University, Ghent, Belgium
| | - Alok Ranjan Nayak
- Department of Physics, Centre for Condensed Matter Theory, Indian Institute of Science, Bangalore, Karnataka, India
- Robert Bosch Centre for Cyber Physical Systems, Indian Institute of Science, Bangalore, Karnataka, India
| | - Alexander V. Panfilov
- Department of Physics and Astronomy, Ghent University, Ghent, Belgium
- Moscow Institute of Physics and Technology (State University), Dolgoprudny, Moscow Region, Russia
| | - Rahul Pandit
- Department of Physics, Centre for Condensed Matter Theory, Indian Institute of Science, Bangalore, Karnataka, India
- Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, Karnataka, India
- * E-mail:
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Buffery PJ, Strother RM. Domperidone safety: a mini-review of the science of QT prolongation and clinical implications of recent global regulatory recommendations. N Z Med J 2015; 128:66-74. [PMID: 26117678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
AIMS In New Zealand, domperidone is approved for gastrointestinal motility and nausea and vomiting. The European Medicines Agency (EMA) recently concluded that domperidone poses a significant risk of sudden cardiac death (SCD) and has restricted use in Europe. This paper reviews the risk of QT prolongation and cardiac adverse effects with domperidone and provide information to allow prescribers to make informed decisions on usage. METHODS A search of two bibliographic databases, the European Medicines Agency (EMA) website, Micromedex, Lexicomp and reference texts was undertaken for domperidone related reports of QT prolongation, cardiac arrhythmias and/or SCD. The New Zealand Centre for Adverse Drugs Reaction Monitoring was also contacted for cardiac adverse event reports with domperidone. RESULTS Over 30 published papers, EMA documents and other information sources were collated, including two studies that met thorough QT study (TQT) criteria (ICH-E14). The first TQT1 was negative while the second was marginally positive. Reports of QT prolongation, ventricular arrhythmias and SCD were located (predominantly high/very high-dose IV domperidone). With oral domperidone, a Dutch case-controlled study reported an adjusted odds ratio of SCD of 11.4 (95% CI 1.99-65.2), based on only three patients out of 1,366 cases of SCD. A second nested case-controlled study calculated an odds ratio of ventricular arrhythmia or SCD of 1.59 (1.28-1.98) vs. placebo. DISCUSSION Based on the results of the two TQT (the regulatory agency gold standard for assessment of QT prolongation) domperidone does not appear to be strongly associated with QT prolongation at oral doses of 20 mg QID in healthy volunteers. Further, there are limited case reports supporting an association with cardiac dysfunction, and the frequently cited case-control studies have significant flaws. While there remains an ill-defined risk at higher systemic concentrations, especially in patients with a higher baseline risk of QT prolongation, our review does not support the view that domperidone presents intolerable risk.
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Affiliation(s)
- Pamela J Buffery
- Department of Clinical Pharmacology, Christchurch Hospital, Private Bag 4710, Christchurch 8140, New Zealand.
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Poncet A, Gencer B, Blondon M, Gex-Fabry M, Combescure C, Shah D, Schwartz PJ, Besson M, Girardin FR. Electrocardiographic Screening for Prolonged QT Interval to Reduce Sudden Cardiac Death in Psychiatric Patients: A Cost-Effectiveness Analysis. PLoS One 2015; 10:e0127213. [PMID: 26070071 PMCID: PMC4466505 DOI: 10.1371/journal.pone.0127213] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [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: 01/30/2015] [Accepted: 04/13/2015] [Indexed: 12/28/2022] Open
Abstract
IMPORTANCE Sudden cardiac death is a leading cause of mortality in psychiatric patients. Long QT (LQT) is common in this population and predisposes to Torsades-de-Pointes (TdP) and subsequent mortality. OBJECTIVE To estimate the cost-effectiveness of electrocardiographic screening to detect LQT in psychiatric inpatients. DESIGN, SETTING, AND PARTICIPANTS We built a decision analytic model based on a decision tree to evaluate the cost-effectiveness and utility of LQT screening from a health care perspective. LQT proportion parameters were derived from an in-hospital cross-sectional study. We performed experts' elicitation to estimate the risk of TdP, given extent of QT prolongation. A TdP reduction of 65% after LQT detection was based on positive drug dechallenge rate and through adequate treatment and electrolyte adjustments. The base-case model uncertainty was assessed with one-way and probabilistic sensitivity analyses. Finally, the TdP related mortality and TdP avoidance parameters were varied in a two-way sensitivity analysis to assess their effect on the Incremental Cost-Effectiveness Ratio (ICER). MAIN OUTCOMES AND MEASURES Costs, Quality Ajusted Life Year (QALY), ICER, and probability of cost effectiveness thresholds ($ 10,000, $25,000, and $50,000 per QALY). RESULTS In the base-case scenario, the numbers of patients needed to screen were 1128 and 2817 to avoid one TdP and one death, respectively. The ICER of systematic ECG screening was $8644 (95%CI, 3144-82 498) per QALY. The probability of cost-effectiveness was 96% at a willingness-to-pay of $50,000 for one QALY. In sensitivity analyses, results were sensitive to the case-fatality of TdP episodes and to the TdP reduction following the diagnosis of LQT. CONCLUSION AND RELEVANCE In psychiatric hospitals, performing systematic ECG screening at admission help reduce the number of sudden cardiac deaths in a cost-effective fashion.
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Affiliation(s)
- Antoine Poncet
- Department of Health and Community Medicine, University Hospitals and University of Geneva, rue Gabrielle-Perret-Gentil 4, 1205, Geneva, Switzerland
| | - Baris Gencer
- Cardiology Division, University Hospitals and University of Geneva, rue Gabrielle-Perret-Gentil 4, 1205, Geneva, Switzerland
| | - Marc Blondon
- Department of Internal Medicine, University Hospitals and University of Geneva, rue Gabrielle-Perret-Gentil 4, 1205, Geneva, Switzerland
| | - Marianne Gex-Fabry
- Department of Psychiatry, University Hospitals and University of Geneva, 2 chemin du Petit-Bel-Air, 1225, Chêne-Bourg, Switzerland
| | - Christophe Combescure
- Department of Health and Community Medicine, University Hospitals and University of Geneva, rue Gabrielle-Perret-Gentil 4, 1205, Geneva, Switzerland
| | - Dipen Shah
- Cardiology Division, University Hospitals and University of Geneva, rue Gabrielle-Perret-Gentil 4, 1205, Geneva, Switzerland
| | - Peter J. Schwartz
- Center for Cardiac Arrhythmias of Genetic Origin, IRCCS Istituto Auxologico Italiano, Milano, Italy
| | - Marie Besson
- Department of Anesthesiology, Intensive Care, and Clinical Pharmacology, University Hospitals and University of Geneva, rue Gabrielle-Perret-Gentil 4, 1205, Geneva, Switzerland
| | - François R. Girardin
- Department of Anesthesiology, Intensive Care, and Clinical Pharmacology, University Hospitals and University of Geneva, rue Gabrielle-Perret-Gentil 4, 1205, Geneva, Switzerland
- Medical Directorate, University Hospitals and University of Geneva, rue Gabrielle-Perret-Gentil 4, 1205, Geneva, Switzerland
- Centre for Health Economics, University of York, Heslington,York, United Kingdom
- * E-mail:
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Lau E, Kossidas K, Kim TY, Kunitomo Y, Ziv O, Zhen S, Taylor C, Schofield L, Yammine J, Liu G, Peng X, Qu Z, Koren G, Choi BR. Spatially Discordant Alternans and Arrhythmias in Tachypacing-Induced Cardiac Myopathy in Transgenic LQT1 Rabbits: The Importance of IKs and Ca2+ Cycling. PLoS One 2015; 10:e0122754. [PMID: 25970695 PMCID: PMC4430457 DOI: 10.1371/journal.pone.0122754] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Accepted: 02/12/2015] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Remodeling of cardiac repolarizing currents, such as the downregulation of slowly activating K+ channels (IKs), could underlie ventricular fibrillation (VF) in heart failure (HF). We evaluated the role of Iks remodeling in VF susceptibility using a tachypacing HF model of transgenic rabbits with Long QT Type 1 (LQT1) syndrome. METHODS AND RESULTS LQT1 and littermate control (LMC) rabbits underwent three weeks of tachypacing to induce cardiac myopathy (TICM). In vivo telemetry demonstrated steepening of the QT/RR slope in LQT1 with TICM (LQT1-TICM; pre: 0.26±0.04, post: 0.52±0.01, P<0.05). In vivo electrophysiology showed that LQT1-TICM had higher incidence of VF than LMC-TICM (6 of 11 vs. 3 of 11, respectively). Optical mapping revealed larger APD dispersion (16±4 vs. 38±6 ms, p<0.05) and steep APD restitution in LQT1-TICM compared to LQT1-sham (0.53±0.12 vs. 1.17±0.13, p<0.05). LQT1-TICM developed spatially discordant alternans (DA), which caused conduction block and higher-frequency VF (15±1 Hz in LQT1-TICM vs. 13±1 Hz in LMC-TICM, p<0.05). Ca2+ DA was highly dynamic and preceded voltage DA in LQT1-TICM. Ryanodine abolished DA in 5 out of 8 LQT1-TICM rabbits, demonstrating the importance of Ca2+ in complex DA formation. Computer simulations suggested that HF remodeling caused Ca2+-driven alternans, which was further potentiated in LQT1-TICM due to the lack of IKs. CONCLUSIONS Compared with LMC-TICM, LQT1-TICM rabbits exhibit steepened APD restitution and complex DA modulated by Ca2+. Our results strongly support the contention that the downregulation of IKs in HF increases Ca2+ dependent alternans and thereby the risk of VF.
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Affiliation(s)
- Emily Lau
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, Rhode Island, United States of America
| | - Konstantinos Kossidas
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, Rhode Island, United States of America
| | - Tae Yun Kim
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, Rhode Island, United States of America
| | - Yukiko Kunitomo
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, Rhode Island, United States of America
| | - Ohad Ziv
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, Rhode Island, United States of America
| | - Song Zhen
- Department of Medicine (Cardiology), David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Chantel Taylor
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, Rhode Island, United States of America
| | - Lorraine Schofield
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, Rhode Island, United States of America
| | - Joe Yammine
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, Rhode Island, United States of America
| | - Gongxin Liu
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, Rhode Island, United States of America
| | - Xuwen Peng
- Department of Comparative Medicine, Pennsylvania State University College of Medicine, Hershey, Pennsylvania, United States of America
| | - Zhilin Qu
- Department of Medicine (Cardiology), David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Gideon Koren
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, Rhode Island, United States of America
| | - Bum-Rak Choi
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, Rhode Island, United States of America
- * E-mail:
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Huang Y, Dai M, Du YM, Yao YF, Zhang JM, Su GH, Shu YW, Cui TP, Du XL, Li JD. [Combined transgenic inhibition of CaMKII and Ik1 on cardiac remodeling]. Sheng Li Xue Bao 2015; 67:201-206. [PMID: 25896051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
This study was aimed to establish an experimental mouse model of combined transgenic inhibition of both multifunctional Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) and inward rectifier potassium current (Ik1), and to observe whether the specific inhibition of both CaMKII and Ik1 can bring about any effects on cardiac remodeling. Mice were divided into 4 groups: wild type (WT), CaMKII inhibited (AC3-I), Ik1 inhibited (Kir2.1-AAA) and combined inhibition of both CaMKII and Ik1 (AC3-I+Kir2.1-AAA). Mice in each group received electrocardiogram (ECG) and echocardiography examination. ECG in the condition of isoproterenol (ISO) injection was also checked. The whole cell patch clamp technique was used to measure Ik1 and the transient outward potassium current (Ito) from enzymatically isolated myocytes of left ventricle. In the condition of basal status, no significant changes of heart rate, PR interval and QRS interval were observed. No mouse showed ventricular arrhythmias in all of the 4 groups. After ISO injection, each group presented no significant ventricular arrhythmias either. The indexes measured by M-mode (motion-mode) and two-dimensional echocardiography had no significant differences among the four groups. Ik1 in AC3-I group was significantly higher than those in other three groups (P < 0.01) because of the results brought about by CaMKII inhibition. Among the latter three groups, both Kir2.1-AAA group and AC3-I+Kir2.1-AAA group had a significant reduced Ik1 compared with that of WT group, which was due to the Ik1 inhibition (P < 0.01). Ito in AC3-I group was higher than that of the other three groups (P < 0.01), but there were no significant differences in Ito among WT, Kir2.1-AAA and AC3-I+Kir2.1-AAA groups. Thus, combined transgenic myocardial CaMKII and Ik1 inhibition eliminated the up-regulation of Ik1 in CaMKII inhibited mice, and had no effects on cardiac remodeling including heart structure and function as well as arrhythmias at the basic and ISO conditions. The results of this study may provide a basis for the further investigation of combined inhibition of CaMKII and Ik1 in pathogenic cardiac remodeling.
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Affiliation(s)
- Yun Huang
- Department of Gerontology, Union Hospital, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Miao Dai
- Department of Gerontology, Union Hospital, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Yi-Mei Du
- Department of Cardiology, Union Hospital, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Yu-Feng Yao
- Life Science College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Jia-Ming Zhang
- Department of Cardiology, Union Hospital, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Guan-Hua Su
- Department of Cardiology, Union Hospital, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Yan-Wen Shu
- Department of Cardiology, Union Hospital, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Tian-Pen Cui
- Laboratory Medicine Center, the First Hospital of Wuhan, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Xin-Ling Du
- Department of Cardiac Surgery of Union Hospital, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Jing-Dong Li
- Department of Cardiology, Union Hospital, Huazhong University of Science and Technology, Wuhan 430022, China.
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Malm JR, Krongrad E, Waldo AL, Reemtsma K, Hoffman BF. Current methodology in total correction of congenital cardiac malformations. Electrophysiologic considerations. Adv Cardiol 2015; 11:67-73. [PMID: 4412681 DOI: 10.1159/000395206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Russo V, Di Meo F, Rago A, Papa AA, Molino A, Mosella M, Politano L, Russo MG, Nigro G. Paroxysmal atrial fibrillation in myotonic dystrophy type 1 patients: P wave duration and dispersion analysis. Eur Rev Med Pharmacol Sci 2015; 19:1241-1248. [PMID: 25912584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
OBJECTIVE Myotonic dystrophy type 1 (MD1) is characterized by cardiac involvement, in about 80% of case, that predominantly affects the conduction system. Aim of our study was to evaluate the P-wave duration and dispersion (PD) in MD1 patients underwent pacemaker implantation with conserved systolic and diastolic function. PATIENTS AND METHODS We enrolled 60 MD1 patients (age 51.3 ± 5 years; 11 females) underwent dual chamber pacemaker implantation for various grade of atrioventricular (AV) block. Sixty sex-and age matched non-MD1 subjects were recruited as controls. P-wave duration and dispersion were carefully measured using 12-lead electrocardiogram. RESULTS Compared with healthy control group, MD1 patients presented increased maximum P wave duration (106.4 ± 20.9 vs 65.9 ± 8.2 ms, p = 0.03) and PD values (40.1 ± 11 vs 27.1 ± 4.2 ms, p = 0.003). No statistically significant difference was found in minimum P wave duration (69.7 ± 11.8 vs 65.4 ± 8.1 ms, p = 0.4). The MD1 patients with paroxysmal atrial fibrillation, compared with MD1 patients without evidence of atrial fibrillation, presented increased maximum P wave duration (108.1 ± 10.4 vs 78.1 ± 7.9 ms, p = 0.001) and PD values (41.1 ± 8.5 vs 33.2 ± 4.2 ms, p = 0.003). Minimum P wave duration (68.4 ± 8.2 vs 67.1 ± 4.9 ms, p = 0.5) didn't differ between the two groups. CONCLUSIONS Our data showed a significantly increased P wave duration and dispersion in MD1 patients compared with age and sex-matched healthy controls. We showed a statistically significant increase in PD and P max in MD1 patients subgroup with AF compared to MD1 patients with no arrhythmias.
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Affiliation(s)
- V Russo
- Chair of Cardiology, Second University of Naples, Monaldi Hospital, Naples, Italy.
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Jianyong L, Jianbin L, Menglin L, Yue X, Qi Y, Yifang Y, Yan Y, Jingying Y. [Continuous positive airway pressure treatment for functional cardiac arrhythmias combined with obstructive sleep apnea hypopnea syndrome]. Zhonghua Er Bi Yan Hou Tou Jing Wai Ke Za Zhi 2015; 50:221-224. [PMID: 26268495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
OBJECTIVE To discuss the effect of continuous positive airway pressure (CPAP) treatment for functional cardiac arrhythmias combined with obstructive sleep apnea hypopnea syndrome. METHODS Fifty-six OSAHS patients combined functional cardiac arrhythmia were randomized divided into two groups. The 28 patients in the control group were treated with metoprolol according to cardiac guidelines, the other 28 cases in the experimental group were treated with CPAP therapy combined with metoprolol. AHI and the lowest oxygen saturation (LSaO2) were tested before and after treatment. RESULTS The efficiency rates were 57.1% and 17.9% in experimental and control group respectively, with statistical difference (χ2 = 7.62, P < 0.01). Total effective rates were 85.7% and 53.6% respectively, with statistical difference (χ2 = 5.41, P < 0.05). In the experimental group, there were three treatment subgroups. After treatment, AHI and the lowest oxygen saturation were significantly different (P < 0.05). CONCLUSION CPAP treatment can effectively eliminate respiratory disturbance index, improve the symptoms of hypooxygen at night, and effectively improve the therapeutic effect of functional cardiac arrhythmias in OSAHS patients combined with functional arrhythmia.
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Matoshvili ZT, Petriashvili SG, Archadze AT, Azaladze IG. Early repolarization as a predictor of premature ventricular beats. Georgian Med News 2015:44-47. [PMID: 25802448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Early repolarization pattern (ERP) is a common ECG variant, characterized by J point elevation manifested either as terminal QRS slurring (the transition from the QRS segment to the ST segment) or notching (a positive deflection inscribed on terminal QRS complex) associated with concave upward ST-segment elevation and prominent T waves in at least two contiguous leads. Aim of this observational study was to compare number of premature ventricular beats in the different groups of patients with early repolarization. The result of this observational study shows that there are: 1,74 fold higher number of premature ventricular beats in 41-74 year subgroup VS 19-40 year subgroup; 1,31 fold higher number of premature ventricular beats in male subgroup VS female subgroup (But this difference is not statistically significant, because t=1,49, p=0,141); 2,85 fold higher number of premature ventricular beats in CAD+ERP subgroup VS ERP without CAD subgroup; 1,74 fold higher number of premature ventricular beats in HF+ERP subgroup VS ERP without HF subgroup; 1,81 fold higher number of premature ventricular beats in CAD+ERP subgroup VS CAD without ERP subgroup; 1,58 fold higher number of premature ventricular beats in HF+ERP subgroup VS HF without ERP subgroup; So, CAD+ERP is very arrhythmogenic condition, after this is HF+ERP, Then Age. This study shows that ERP independently increase number of PVB in different groups (CAD, HF). This is principally new and very important result. Also the number of patients is enough to make this conclusion.
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Radszuweit M, Alvarez-Lacalle E, Bär M, Echebarria B. Cardiac contraction induces discordant alternans and localized block. Phys Rev E Stat Nonlin Soft Matter Phys 2015; 91:022703. [PMID: 25768527 DOI: 10.1103/physreve.91.022703] [Citation(s) in RCA: 3] [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] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Indexed: 06/04/2023]
Abstract
In this paper we use a simplified model of cardiac excitation-contraction coupling to study the effect of tissue deformation on the dynamics of alternans, i.e., alternations in the duration of the cardiac action potential, that occur at fast pacing rates and are known to be proarrhythmic. We show that small stretch-activated currents can produce large effects and cause a transition from in-phase to off-phase alternations (i.e., from concordant to discordant alternans) and to conduction blocks. We demonstrate numerically and analytically that this effect is the result of a generic change in the slope of the conduction velocity restitution curve due to electromechanical coupling. Thus, excitation-contraction coupling can potentially play a relevant role in the transition to reentry and fibrillation.
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Affiliation(s)
- M Radszuweit
- Weierstrass Institute for Applied Analysis and Stochastics Mohrenstrasse 39, 10117 Berlin, Germany
| | - E Alvarez-Lacalle
- Departament de Física Aplicada, Universitat Politècnica de Catalunya.BarcelonaTech, Av. Dr. Marañón 44-50, E-08028, Barcelona, Spain
| | - M Bär
- Physikalisch-Technische Bundesanstalt, 10587 Berlin, Germany
| | - B Echebarria
- Departament de Física Aplicada, Universitat Politècnica de Catalunya.BarcelonaTech, Av. Dr. Marañón 44-50, E-08028, Barcelona, Spain
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Nguyen BL, Capotosto L, Persi A, Placanica A, Rafique A, Piccirillo G, Gaudio C, Gang ES, Siegel RJ, Vitarelli A. Global and regional left ventricular strain indices in post-myocardial infarction patients with ventricular arrhythmias and moderately abnormal ejection fraction. Ultrasound Med Biol 2015; 41:407-417. [PMID: 25542492 DOI: 10.1016/j.ultrasmedbio.2014.09.025] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Revised: 09/15/2014] [Accepted: 09/19/2014] [Indexed: 06/04/2023]
Abstract
The aim of the study described here was to compare myocardial strains in ischemic heart patients with and without sustained ventricular tachycardia (VT) and moderately abnormal left ventricular ejection fraction (LVEF) to investigate which index could better predict VT on the basis of the analysis of global and regional left ventricular (LV) dysfunction. We studied 467 patients with previous myocardial infarction and LVEF >35%. Fifty-one patients had documented VT, and 416 patients presented with no VT. LV volumes and score index were obtained by 2-D echocardiography. Longitudinal, radial and circumferential strains were determined. Strains of the infarct, border and remote zones were also obtained. There were no differences in standard LV 2-D parameters between patients with and those without VT. Receiver operating characteristic values were -12.7% for global longitudinal strain (area under the curve [AUC] = 0.72), -4.8% for posterior-inferior wall circumferential strain (AUC = 0.80), 61 ms for LV mechanical dispersion (AUC = 0.84), -10.1% for longitudinal strain of the border zone (AUC = 0.86) and -9.2% for circumferential strain of the border zone (AUC = 0.89). In patients with previous myocardial infarction and moderately abnormal LVEF, peri-infarct circumferential strain was the strongest predictor of documented ventricular arrhythmias among all strain quantitative indices. Additionally, strain values from posterior-inferior wall infarctions had a higher association with arrhythmic events compared with global strain.
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Affiliation(s)
| | | | | | | | - Asim Rafique
- Cedars-Sinai Medical Center, Los Angeles, California, USA
| | | | | | - Eli S Gang
- Cedars-Sinai Medical Center, Los Angeles, California, USA
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Liu GX, Remme CA, Boukens BJ, Belardinelli L, Rajamani S. Overexpression of SCN5A in mouse heart mimics human syndrome of enhanced atrioventricular nodal conduction. Heart Rhythm 2015; 12:1036-45. [PMID: 25623181 DOI: 10.1016/j.hrthm.2015.01.029] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Indexed: 11/19/2022]
Abstract
BACKGROUND In enhanced atrioventricular (A-V) nodal conduction (EAVNC) syndrome, patients have short A-V conduction times. Multiple mechanisms have been proposed to explain EAVNC; however, the electrophysiological or molecular substrate responsible for it remains unclear. OBJECTIVE The purpose of this study was to test the hypothesis that overexpression of SCN5A in the mouse heart may provide an animal model mimicking EAVNC. METHODS Electrocardiogram, atrial, His bundle, and ventricular electrograms were recorded from wild-type (WT) and transgenic (TG) mice overexpressing human SCN5A. The sodium current and NaV1.5 expression were measured using patch-clamp and immunohistochemistry techniques. RESULTS The P-R interval in TG mice (13.6 ± 1.2 ms) was much shorter than that in WT mice (40.2 ± 0.59 ms). In TG isolated hearts, the A-V conduction time (14.4 ± 0.81 ms) during right atrial pacing was also shorter than that in WT hearts (39.5 ± 0.62 ms). Records of His bundle electrograms revealed that atrial-to-His and His-to-ventricular intervals were shorter in TG than in WT hearts. In addition, TG hearts had a shorter Wenckebach cycle length and A-V effective refractory period. The sodium current was 2-fold greater in TG ventricular myocytes than in WT ventricular myocytes. Flecainide prolonged the A-V conduction time in TG hearts to a value close to that in WT hearts. Nifedipine prolonged the atrial-to-His interval in WT hearts but not in TG hearts. Immunohistochemistry studies revealed increased NaV1.5 labeling in TG atrial and ventricular tissues, and NaV1.5 expression in A-V junction and A-V ring regions in TG hearts. CONCLUSION Enhanced A-V conduction in mice overexpressing SCN5A in the heart mimics the human syndrome of EAVNC. Thus, variants in sodium channel expression in the A-V nodal region may be an electrophysiological substrate responsible for EAVNC.
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Affiliation(s)
- Gong Xin Liu
- Department of Biology, Gilead Sciences, Fremont, California
| | - Carol Ann Remme
- Department of Experimental Cardiology, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
| | - Bastiaan J Boukens
- Department of Biomedical Engineering, Washington University, St. Louis, Missouri
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Elitok A, Ikitimur B, Onur I, Oz F, Emet S, Karaayvaz EB, Serbest NG, Sarikaya R, Kasali K, Bilge AK, Kaya MG, Mercanoglu F, Oflaz H. The relationship between T-wave peak-to end interval and ST segment recovery on intracoronary ECG during primary PCI. Eur Rev Med Pharmacol Sci 2015; 19:1086-1091. [PMID: 25855936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
OBJECTIVE T-wave peak to end interval (TPE) is a measure of repolarization dispersion, which has been reported as a major arrhythmogenic factor post acute myocardial infarction. The aim of our study was to investigate the changes in TPE in this patient population with regard to peri-procedural intracoronary ECG findings. PATIENTS AND METHODS Forty-four patients (34 male and mean age of 54.9 ± 10.9 years) with acute STEMI were included. Intracoronary ECG was performed during primary PCI. TPE indices were calculated before and after the procedure. Measurement of the intracoronary ST-segment was carried out before and just after coronary blood flow was established in the infarct related artery. Intracoronary ST-segment resolution (IC-STR) was defined as ≥ 1 mm compared to baseline. RESULTS There was no difference with respect to baseline characteristics when patients with IC-STR were compared with patients without IC-STR. TPE values decreased significantly after primary PCI in patients with IC-STR (80.9 ± 22.8 ms vs. 65.8 ± 14.4 ms; p < 0.001) whereas they did not change significantly after PCI in patients without IC-STR (79.2 ± 20.9 ms vs. 68.5 ± 16.3 ms; p = 0.18). CONCLUSIONS TPE measured from surface ECG recordings is significantly reduced in STEMI patients with successful reperfusion after primary PCI, as determined by IC-ECG recordings.
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Affiliation(s)
- A Elitok
- Department of Cardiology, Istanbul University, School of Medicine, Istanbul, Turkey.
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Kong L, He B. [Optimal intervention timing for patients with non-ST-segment elevation acute coronary syndromes]. Zhonghua Xin Xue Guan Bing Za Zhi 2015; 43:79-81. [PMID: 25876731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
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Mironov NY, Berezina ES, Golitsyn SP. [Congenital Cardiac Conduction Abnormalities]. Kardiologiia 2015; 55:83-90. [PMID: 26502508 DOI: 10.18565/cardio.2015.4.83-90] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Abnormalities in cardiac conduction can occur due to a variety of factors. So called "idiopathic", conduction system degeneration develops without evident causes and may have hereditary basis. In the majority of cases it has no clinical manifestation, do not require treatment and have overall good prognosis. In this review we focus on congenital complete atrioventricular block and progressive cardiac conduction defect - rare but malignant and potentially lethal conditions that can be caused by genetic mutations and may be isolated or associated with structural heart disease. Cardiac involvement is relatively common in rare hereditary diseases - myodystrophies and mitochondrial cytopathies. Conduction abnormalities are among the most severe manifestations that may determine prognosis in these rare genetic disorders. These conditions deserve special consideration because of rapid progression of conduction defects and high prevalence of sudden cardiac death if no appropriate treatment applied.
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Wang YP, Chen BX, Su KJ, Sun LJ, Zhang Y, Guo LJ, Gao W. [Hyperkalemia-induced failure of pacemaker capture and sensing: a case report]. Beijing Da Xue Xue Bao Yi Xue Ban 2014; 46:980-982. [PMID: 25512296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Hyperkalemia may induce serious cardiac arrhythmia, with possible life-threatening effects. It may cause cardiac pacemaker (PMK) malfunctioning due to a reduction of the electronegativity of the resting myocardial potential. We report the case of a 71-year-old woman who had a previous history of chronic heart failure, chronic renal failure and DDI pacemaker. She was admitted for disturbance of consciousness. During hospitalization, she was observed for extreme hypotension, acute hyperkalemia, ventricular escape rhythm, associated with failure of pacemaker capture and sensing. She was treated with calcium chloride injection, followed by insulin/glucose and sodium bicarbonate infusions; the electrocardiogram recordings showed an correction of the PMK malfunctioning and serial improvement of the intraventricular conduction. This case supports that hyperkalemia should be closely monitored in the chronic heart failure patients combined with chronic renal failure.
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Affiliation(s)
- Y P Wang
- Department of Cardiology, Peking University Third Hospital, Beijing 100191, China
| | - B X Chen
- Department of Cardiology, Peking University Third Hospital, Beijing 100191, China
| | - K J Su
- Department of Cardiology, Peking University Third Hospital, Beijing 100191, China
| | - L J Sun
- Department of Cardiology, Peking University Third Hospital, Beijing 100191, China
| | - Y Zhang
- Department of Cardiology, Peking University Third Hospital, Beijing 100191, China
| | - L J Guo
- Department of Cardiology, Peking University Third Hospital, Beijing 100191, China
| | - W Gao
- Department of Cardiology, Peking University Third Hospital, Beijing 100191, China
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BET 2: should ST elevation be measured at the J point or 60 ms later? Emerg Med J 2015; 32:88-9. [PMID: 25511632 DOI: 10.1136/emermed-2014-204467.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
A shortcut systematic review was carried out to establish whether in patients with suspected acute coronary syndromes presenting to the emergency department, measurement of electrocardiographic ST elevation at the J point or 60 ms after the J point will lead to more accurate identification of patients with acute coronary occlusion who may benefit from immediate coronary revascularisation. Three studies were directly relevant to the question. The author, date and country of publication, patient group studied, study type, relevant outcomes, results and study weaknesses of these papers are tabulated. The clinical bottom line is that the current evidence does not justify a shift away from measurement of ST elevation at the J point, as advocated in international guidance. Due to the limited available evidence, however, further research in this area is necessary.
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Abstract
Mutations in SCN5A, which encodes the α subunit of the major cardiac sodium channel Na(V)1.5, are associated with multiple cardiac arrhythmias, including Brugada syndrome. It is not clear why mutations in SCN5A result in such a variety of cardiac phenotypes, and introduction of analogous Scn5a mutations into small-animal models has not recapitulated alterations in cardiac physiology associated with human disease. In this issue of the JCI, Park and colleagues present a pig model of cardiac sodium channelopathy that was generated by introducing a human Brugada syndrome-associated SCN5A allele. This large-animal model exhibits many phenotypes seen in patients with SCN5A loss-of-function mutations and has the potential to provide important insight into sodium channelopathies.
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Park DS, Cerrone M, Morley G, Vasquez C, Fowler S, Liu N, Bernstein SA, Liu FY, Zhang J, Rogers CS, Priori SG, Chinitz LA, Fishman GI. Genetically engineered SCN5A mutant pig hearts exhibit conduction defects and arrhythmias. J Clin Invest 2014; 125:403-12. [PMID: 25500882 DOI: 10.1172/jci76919] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Accepted: 10/16/2014] [Indexed: 12/19/2022] Open
Abstract
SCN5A encodes the α subunit of the major cardiac sodium channel Na(V)1.5. Mutations in SCN5A are associated with conduction disease and ventricular fibrillation (VF); however, the mechanisms that link loss of sodium channel function to arrhythmic instability remain unresolved. Here, we generated a large-animal model of a human cardiac sodium channelopathy in pigs, which have cardiac structure and function similar to humans, to better define the arrhythmic substrate. We introduced a nonsense mutation originally identified in a child with Brugada syndrome into the orthologous position (E558X) in the pig SCN5A gene. SCN5A(E558X/+) pigs exhibited conduction abnormalities in the absence of cardiac structural defects. Sudden cardiac death was not observed in young pigs; however, Langendorff-perfused SCN5A(E558X/+) hearts had an increased propensity for pacing-induced or spontaneous VF initiated by short-coupled ventricular premature beats. Optical mapping during VF showed that activity often began as an organized focal source or broad wavefront on the right ventricular (RV) free wall. Together, the results from this study demonstrate that the SCN5A(E558X/+) pig model accurately phenocopies many aspects of human cardiac sodium channelopathy, including conduction slowing and increased susceptibility to ventricular arrhythmias.
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Celikbilek A, Sarikaya S, Zararsiz G, Tanik N, Erbay AR. Assessment of atrial electromechanical delay in patients with migraine. Acta Neurol Belg 2014; 114:261-7. [PMID: 24399200 DOI: 10.1007/s13760-013-0273-8] [Citation(s) in RCA: 2] [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: 10/22/2013] [Accepted: 12/17/2013] [Indexed: 12/01/2022]
Abstract
Evidence suggests that symptoms of migraine are related to the involvement of the autonomic nervous system. Data on atrial conduction system are limited in migraineurs. We aimed to assess atrial electromechanical delay using tissue Doppler imaging (TDI) in patients with migraine. Forty-five migraine patients and age- and sex-matched 26 control subjects were enrolled in the study. All the patients and controls underwent resting surface electrocardiogram (ECG) and TDI. The maximum P-wave duration (Pmax), minimum P-wave duration (Pmin) and P-wave dispersion (Pd) were measured from the 12-lead ECG. Atrial conduction time was determined from the lateral mitral annulus (PA lateral), septal mitral annulus (PA septal), and lateral tricuspid annulus (PA tricuspid) by TDI. Interatrial (PA lateral-PA tricuspid) and intraatrial (PA septal-PA tricuspid) electromechanical delays were calculated. Pd was significantly higher in migraine patients than in controls (p < 0.05), whereas Pmax and Pmin were not different between both groups (p > 0.05). PA lateral and PA septal durations were significantly higher in migraine patients than in controls (p < 0.001 and p < 0.05, respectively). However, PA tricuspid duration was similar between the groups (p > 0.05). Both interatrial and intraatrial conduction times were delayed in migraineurs as compared to the controls (p < 0.001). Interatrial delay and intraatrial delay variables were found as an independent risk factors separately on predicting atrial conduction abnormalities in migraineurs. An interatrial delay of 18 ms and an intraatrial delay of 5 ms were found to be cutoff values in ROC analysis (p < 0.001). This is the first report to provide a hypothetical suggestion that there is an atrial electromechanical delay in patients with migraine.
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Affiliation(s)
- Asuman Celikbilek
- Department of Neurology, Medical School, Bozok University, Yozgat, 66200, Turkey,
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35
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Kautzner J, Peichl P. [Catheter ablation of focus triggering ventricular fibrillation in patients with structural heart disease]. Vnitr Lek 2014; 60:1055-1061. [PMID: 25692832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
First experiences with ablation of focus triggering ventricular fibrillation were reported in isolated cases of idiopathic ventricular fibrillation. Later, there were described the options in management of an electrical instability triggered by ectopic activity in patients after myocardial infarction. In both cases it was shown that the sources of extrasystoles originate almost exclusively from conducting system of chambers. Subsequently, isolated cases were also reported in other structural diseases. It is important that the urgent catheter ablation is able to remove focus which triggers electric instability. In many cases it is a lifesaving procedure. This review summarizes the current knowledge of the catheter ablation of focus triggering ventricular fibrillation with structural heart disease.
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Kytö V, Sipilä J, Rautava P. Rate and patient features associated with recurrence of acute myocarditis. Eur J Intern Med 2014; 25:946-50. [PMID: 25468248 DOI: 10.1016/j.ejim.2014.11.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Revised: 10/27/2014] [Accepted: 11/03/2014] [Indexed: 02/06/2023]
Abstract
BACKGROUND Rate and patient features associated with recurrence after acute myocarditis are largely unknown. METHODS AND RESULTS First recurrence of acute myocarditis was studied in 1662 patients aged 16-70 years using a registry data of 29 hospitals in Finland (median follow-up 4.5 years). Matched intoxication patients served as controls. Incidence rate of first time hospitalization due to acute myocarditis was 5.52 (CI 5.26-5.79) per 100,000 person-years during 2001-2008. During the first 30 days 5.5% (CI 3.5-4.4%) of patients were re-admitted to hospital with acute myocarditis (p<0.0001 vs. controls). After 30 days, recurrence rate was 7.0% (CI 5.7-8.6%; p<0.0001 vs. controls). Acute myocarditis recurred after 365 days in 4.7% (CI 3.2-6.7%) of patients (p<0.0001 vs. controls). During the whole follow-up, recurrence rate was 10.3% (CI 8.8-12.1%; p<0.0001 vs. controls) with median recurrence time of 34.5 days. Prolonged (>7 days) initial admission was associated with recurrences during (HR 2.9; CI 1.6-5.2) and after first month (HR 1.8; CI 1.2-3.2), and overall (HR 2.0; CI 1.3-3.2). Ventricular arrhythmia at initial occurrence was associated with recurrence after 30 days (HR 8.6; CI 2.5-30.1), after 1 year (HR 22.6; CI 2.5-201.4) and overall (HR 6.7; CI 2.3-6.7). Other features associated with recurrence were younger age (>365 days), inflammatory bowel disease (during first month), and chronic pulmonary disease (≥ 30 days). CONCLUSIONS Acute myocarditis reoccurs in a significant proportion of patients. Prolonged initial admission, ventricular arrhythmias, younger age, inflammatory bowel disease and chronic pulmonary disease are associated with recurrences at different phases after acute myocarditis.
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Affiliation(s)
- Ville Kytö
- Heart Center, Turku University Hospital, Turku, Finland; PET Center, University of Turku, Turku, Finland; Medicine, University of Turku, Turku, Finland.
| | - Jussi Sipilä
- Clinical Neurosciences, Neurology, Turku University Hospital, Turku, Finland; Neurology, University of Turku, Turku, Finland
| | - Päivi Rautava
- Clinical Research Center, Turku University Hospital, Turku, Finland; Public Health, University of Turku, Turku, Finland
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Katsanos S, van Rosendael P, Kamperidis V, van der Kley F, Joyce E, Debonnaire P, Karalis I, Bax JJ, Marsan NA, Delgado V. Insights into new-onset rhythm conduction disorders detected by multi-detector row computed tomography after transcatheter aortic valve implantation. Am J Cardiol 2014; 114:1556-61. [PMID: 25245414 DOI: 10.1016/j.amjcard.2014.08.020] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [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] [Received: 06/23/2014] [Revised: 08/01/2014] [Accepted: 08/01/2014] [Indexed: 11/15/2022]
Abstract
New-onset rhythm conduction disorders are frequent after transcatheter aortic valve implantation (TAVI). Multidetector row computed tomography may shed light on the pathophysiology of rhythm conduction disorders in patients who undergo TAVI with the Edwards SAPIEN valve. A total of 94 patients (mean age 81 ± 7 years, 48% men) treated with TAVI with the Edwards SAPIEN valve who underwent pre- and post-TAVI multidetector row computed tomography were included. Patients with preexisting right bundle branch block or left bundle branch block (LBBB) and permanent pacemakers were excluded. Pacemaker implantation or new-onset LBBB at 1-month follow-up was the combined end point. Overall, 1 pacemaker was implanted, and 14 cases of new-onset LBBB were recorded. Among several clinical and multi-detector row computed tomographic variables, overexpansion of the transcatheter valve >15% of native annular area (odds ratio 5.277, 95% confidence interval 1.398 to 19.919, p = 0.014) and depth of frame into the left ventricular outflow tract (odds ratio 1.401, 95% confidence interval 1.066 to 1.770, p = 0.010) were independently related to the need for a pacemaker or new-onset LBBB. In conclusion, overexpansion of the transcatheter prosthesis by >15% of native aortic annular area and implantation depth of the frame into the left ventricular outflow tract were independently associated with the need for a pacemaker or new-onset LBBB in patients who underwent TAVI with the Edwards SAPIEN valve.
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Affiliation(s)
- Spyridon Katsanos
- Department of Cardiology, Leiden University Medical Centre, Leiden, The Netherlands
| | | | - Vasileios Kamperidis
- Department of Cardiology, Leiden University Medical Centre, Leiden, The Netherlands
| | - Frank van der Kley
- Department of Cardiology, Leiden University Medical Centre, Leiden, The Netherlands
| | - Emer Joyce
- Department of Cardiology, Leiden University Medical Centre, Leiden, The Netherlands
| | - Philippe Debonnaire
- Department of Cardiology, Leiden University Medical Centre, Leiden, The Netherlands
| | - Ioannis Karalis
- Department of Cardiology, Leiden University Medical Centre, Leiden, The Netherlands
| | - Jeroen J Bax
- Department of Cardiology, Leiden University Medical Centre, Leiden, The Netherlands
| | - Nina Ajmone Marsan
- Department of Cardiology, Leiden University Medical Centre, Leiden, The Netherlands
| | - Victoria Delgado
- Department of Cardiology, Leiden University Medical Centre, Leiden, The Netherlands.
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38
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Pei G, Jiang J, Chen Y. [Role of cardiac magnetic resonance in the diagnosis and treatment of ventricular arrhythmia]. Zhonghua Xin Xue Guan Bing Za Zhi 2014; 42:981-984. [PMID: 25620267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
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39
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Aagaard P, Shulman E, Di Biase L, Fisher JD, Gross JN, Kargoli F, Kim SG, Palma EC, Ferrick KJ, Krumerman A. Prognostic value of automatically detected early repolarization. Am J Cardiol 2014; 114:1431-6. [PMID: 25306428 DOI: 10.1016/j.amjcard.2014.07.077] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [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: 06/12/2014] [Revised: 07/18/2014] [Accepted: 07/18/2014] [Indexed: 11/17/2022]
Abstract
Early repolarization associated with sudden cardiac death is based on the presence of >1-mm J-point elevations in inferior and/or lateral leads with horizontal and/or downsloping ST segments. Automated electrocardiographic readings of early repolarization (AER) obtained in clinical practice, in contrast, are defined by ST-segment elevation in addition to J-point elevation. Nonetheless, such automated readings may cause alarm. We therefore assessed the prevalence and prognostic significance of AER in 211,920 patients aged 18 to 75 years. The study was performed at a tertiary medical center serving a racially diverse urban population with a large proportion of Hispanics (43%). The first recorded electrocardiogram of each individual from 2000 to 2012 was included. Patients with ventricular paced rhythm or acute coronary syndrome at the time of acquisition were excluded from the analysis. All automated electrocardiographic interpretations were reviewed for accuracy by a board-certified cardiologist. The primary end point was death during a median follow-up of 8.0 ± 2.6 years. AER was present in 3,450 subjects (1.6%). The prevalence varied significantly with race (African-Americans 2.2%, Hispanics 1.5%, and non-Hispanic whites 0.9%, p <0.01) and gender (male 2.4% vs female 0.6%, p <0.001). In a Cox proportional hazards model controlling for age, smoking status, heart rate, QTc, systolic blood pressure, low-density lipoprotein cholesterol, body mass index, and coronary artery disease, there was no significant difference in mortality regardless of race or gender (relative risk 0.98, 95% confidence interval 0.89 to 1.07). This was true even if J waves were present. In conclusion, AER was not associated with an increased risk of death, regardless of race or gender, and should not trigger additional diagnostic testing.
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Affiliation(s)
- Philip Aagaard
- Division of Cardiology, Department of Medicine, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York
| | - Eric Shulman
- Division of Cardiology, Department of Medicine, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York
| | - Luigi Di Biase
- Division of Cardiology, Department of Medicine, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York
| | - John D Fisher
- Division of Cardiology, Department of Medicine, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York
| | - Jay N Gross
- Division of Cardiology, Department of Medicine, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York
| | - Faraj Kargoli
- Division of Cardiology, Department of Medicine, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York
| | - Soo G Kim
- Division of Cardiology, Department of Medicine, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York
| | - Eugen C Palma
- Division of Cardiology, Department of Medicine, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York
| | - Kevin J Ferrick
- Division of Cardiology, Department of Medicine, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York
| | - Andrew Krumerman
- Division of Cardiology, Department of Medicine, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York.
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40
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Abstract
Atrial fibrillation (AF) is the most common cardiac arrhythmia; however, therapy is suboptimal. We review recent data on dynamics of wave propagation during AF and its mechanistic link to the substrate. Data show that the dominant frequency (DF) increase during transition to persistent AF may be explained by rotor acceleration. We discuss how translation of experimentally derived understanding of the rotors may find its way into the clinic, focusing on studies analyzing spatial distribution of DF in the atria of patients with paroxysmal versus persistent AF, and how that knowledge might contribute to improve the outcome of AF ablation procedures.
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Affiliation(s)
- Omer Berenfeld
- Center for Arrhythmia Research, University of Michigan, 2800 Plymouth Road, Ann Arbor, MI 48109, USA.
| | - José Jalife
- Center for Arrhythmia Research, University of Michigan, 2800 Plymouth Road, Ann Arbor, MI 48109, USA
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41
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Cai W, Zhang Y, Li J, Wang J. [κ-opioid receptor agonist U50, 488H attenuates myocardial ischemia-reperfusionvia modulating Toll-like receptor 4/nuclear factor-κB signaling in rat]. Zhonghua Xin Xue Guan Bing Za Zhi 2014; 42:866-872. [PMID: 25547452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
OBJECTIVE To observe the effects of κ-opioid receptor agonist U50, 488H on myocardial ischemia and reperfusion injury and related mechanism. METHODS Rats were randomly divided into sham operation, myocardial ischemia and reperfusion(I/R, 30 min ischemia followed by 120 min reperfusion), and MI/R+U50, 488H (1.5 mg/kg) and I/R+U50, 488H+ selective κ-opioid receptor antagonist Nor-BNI (2 mg/kg, n = 8 each). The infarction size and the incidence of ventricular arrhythmias were observed.Real-time PCR and DAB staining were used to define the myocardium Toll-like receptor 4(TLR4) expression. Myeloperoxidase level, TNF-α induction and the expression of NF-κB were also examined in rats. RESULTS After I/R, the expressions of myocardial TLR4 and NF-κB increased significantly both in ischemia area and area at risk. Compared with I/R, κ-opioid receptor stimulation with U50, 488H significantly attenuated the expressions of TLR4 and NF-κB and reduced myeloperoxidase (MPO) levels, myocardial TNF-α production, myocardial infarct sizes and the incidence of ventricular arrhythmias and arrhythmia score (2.9 ± 0.7 vs. 4.4 ± 0.9, P < 0.05) , above effects of U50, 488H were partly abolished by co-treatment with Nor-BNI. CONCLUSION These data provide evidence for the first time that κ-opioid receptor stimulation could attenuate myocardial I/R injury via downregulating TLR4/NF-κB signaling in rats.
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Affiliation(s)
| | - Yan Zhang
- Department of Cardiovascular Surgery, Kunming General Hospital of Chengdu Military Region of People's Liberation Army, Chengdu 650032, China
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42
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Gupalo EM, Mironova NA, Rogova MM, Chumachenko PV, Tkachev GA, Naumova MA, Narusov OI, Gerasimova VV, Bakalov SA, Samko AM, Buriachkovskaia LI, Tereshchenko SN, Golitsyn SP. [Assessment of clinical-instrumental, morphological data and expression of coxsackie adenovirus receptor in patients with inflammatory cardiac pathology]. Kardiologiia 2014; 54:8-15. [PMID: 25177881 DOI: 10.18565/cardio.2014.5.8-15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
In 22 patients with heart failure and/or ventricular arrhythmias presumably of inflammatory etiology the results of clinical and instrumental investigation were analyzed and compared to the endomyocardial biopsy data. In the subgroup of patients with left bundle branch block (LBBB) we revealed features indicative of lesser contribution of inflammatory destruction in pathogenesis of cardiomyopathy. The only virus, detected in biopsy samples, was parvovirus B19. Its persistence in myocardium was not related to activity of inflammation and severity of clinical course. Increased expression of Coxsackie adenovirus receptor (CAR) was found in 20 patients. It was not related to inflammatory cells infiltration and virus persistence in myocardium. Patients with most prominent CAR expression were characteried by right heart dilatation, more severe heart failure and absence of LBBB. Enhancement of CAR expression could reflect the attempt of organism to repair intercellular communications between cardiomyocites and to protect cells from the products of necrotic lysis during long standing inflammation.
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43
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Christensen TF, Cichosz SL, Tarnow L, Randløv J, Kristensen LE, Struijk JJ, Eldrup E, Hejlesen OK. Hypoglycaemia and QT interval prolongation in type 1 diabetes--bridging the gap between clamp studies and spontaneous episodes. J Diabetes Complications 2014; 28:723-8. [PMID: 24666922 DOI: 10.1016/j.jdiacomp.2014.03.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Revised: 03/05/2014] [Accepted: 03/05/2014] [Indexed: 01/18/2023]
Abstract
AIMS We propose a study design with controlled hypoglycaemia induced by subcutaneous injection of insulin and matched control episodes to bridge the gap between clamp studies and studies of spontaneous hypoglycaemia. The observed prolongation of the heart rate corrected QT interval (QTc) during hypoglycaemia varies greatly between studies. METHODS We studied ten adults with type 1 diabetes (age 41±15years) without cardiovascular disease or neuropathy. Single-blinded hypoglycaemia was induced by a subcutaneous insulin bolus followed by a control episode on two occasions separated by 4weeks. QT intervals were measured using the semi-automatic tangent approach, and QTc was derived by Bazett's (QTcB) and Fridericia's (QTcF) formulas. RESULTS QTcB increased from baseline to hypoglycaemia (403±20 vs. 433±39ms, p<0.001). On the euglycaemia day, QTcB also increased (398±20 vs. 410±27ms, p<0.01), but the increase was less than during hypoglycaemia (p<0.001). The same pattern was seen for QTcF. Plasma adrenaline levels increased significantly during hypoglycaemia compared to euglycaemia (p<0.01). Serum potassium levels decreased similarly after insulin injection during both hypoglycaemia and euglycaemia. CONCLUSIONS Hypoglycaemia as experienced after a subcutaneous injection of insulin may cause QTc prolongation in type 1 diabetes. However, the magnitude of prolongation is less than typically reported during glucose clamp studies, possible because of the study design with focus on minimizing unwanted study effects.
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Affiliation(s)
- T F Christensen
- Department of Health Science and Technology, Aalborg University, Aalborg, Denmark; Novo Nordisk A/S, Hilleroed, Denmark
| | - S L Cichosz
- Department of Health Science and Technology, Aalborg University, Aalborg, Denmark; Department of Endocrinology and Internal Medicine/Medical Research Laboratory, Aarhus University Hospital, Denmark.
| | - L Tarnow
- Steno Diabetes Center, Gentofte, Denmark; Nordsjaellands Hospitaler, Hilleroed, Denmark
| | - J Randløv
- Novo Nordisk A/S, Hilleroed, Denmark
| | | | - J J Struijk
- Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - E Eldrup
- Steno Diabetes Center, Gentofte, Denmark
| | - O K Hejlesen
- Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
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44
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Singh D, Teo SG, Omar ARB, Poh KK. Electrocardiography series. Narrow QRS-complex tachycardia: part 2. Singapore Med J 2014; 55:451-455. [PMID: 25273927 PMCID: PMC4293938 DOI: 10.11622/smedj.2014112] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
Abstract
We discuss two cases of incessant atrial tachycardia (AT), including the presentation and clinical course. It is important to differentiate AT from other causes of supraventricular tachycardia, such as atrioventricular nodal reentrant tachycardia (AVNRT) and atrioventricular reentrant tachycardia (AVRT), as it would have implications on clinical management. Electrocardiographic features of AT, especially the presence of an AV Wenckebach phenomenon with 'grouped beating', are critical for differentiating AT from AVRT and AVNRT. It is also vital to identify the P waves and their relations to QRS on electrocardiography, as this would aid in the differentiation of various supraventricular tachycardias.
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Affiliation(s)
| | | | | | - Kian Keong Poh
- Department of Cardiology, National University Heart Centre, 1E Kent Ridge Road, NUHS Tower Block, Level 9, Singapore 119228.
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45
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Xia JG, Qu Y, Hu SD, Xu J, Yin CL, Xu D. [Cardioprotective effect and mechanism of intensive lipid modulation on patients with coronary artery disease undergoing noncardiac surgery]. Beijing Da Xue Xue Bao Yi Xue Ban 2014; 46:601-605. [PMID: 25131479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
OBJECTIVE To explore the protective effect and possible mechanism of intensive lipid modulation on the perioperative period of patients with stable coronary artery disease undergoing noncardiac surgery. METHODS In the study, 60 patients with stable coronary artery disease undergoing elective noncardiac surgery were randomly divided into intensive lipid modulation group (n = 30) and conventional group (n = 30). In intensive lipid modulation group, the patients were given atorvastatin 40 mg every night before surgery, 80 mg 12 h before surgery, and 40 mg 2 h before surgery, and 40 mg every night after noncardiac surgery. In conventional group, the patients were given atorvastatin 20 mg every night before surgery and also after the surgery. The occurrence of perioperative major adverse cardiac events (including sudden cardiac death, acute myocardial infarction, unplanned revascularization) were compared in the two groups. Preoperative and 48 h postoperative changes of lipid levels and inflammatory markers were also compared in the two groups. RESULTS In conventional group, one patient suffered myocardial infarction with acute anterior ST-segment elevation and was given emergency left anterior descending artery interventional reperfusion therapy, and 7 patients suffered asymptomatic myocardial infarction. In intensive lipid modulation group, one patient suffered asymptomatic myocardial infarction, and the incidence rate of perioperative acute myocardial infarction reduced significantly compared with conventional group (P < 0.05). There was no significant difference in preoperative and postoperative changes of lipid levels in the two groups (P > 0.05), and compared with conventional group, there was significantly lower levels of inflammatory markers in intensive lipid modulation group (P < 0.05). CONCLUSION The intensive lipid modulation group significantly reduced the incidence of perioperative major adverse cardiac events especially asymptomatic myocardial infarction, and the inhibition of the inflammatory response may be one of the protective mechanisms, which still needs to be further confirmed by large multicenter randomized controlled clinical trials.
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Affiliation(s)
- Jing-gang Xia
- Department of Cardiology, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Yang Qu
- Deparment of Pathology, Beijing Chest Hospital, Capital Medical University, Beijing 101149, China
| | - Shao-dong Hu
- Department of Cardiology, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Ji Xu
- Department of Cardiology, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Chun-lin Yin
- Department of Cardiology, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Dong Xu
- Department of Cardiology, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
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Soltysinska E, Speerschneider T, Winther SV, Thomsen MB. Sinoatrial node dysfunction induces cardiac arrhythmias in diabetic mice. Cardiovasc Diabetol 2014; 13:122. [PMID: 25113792 PMCID: PMC4149194 DOI: 10.1186/s12933-014-0122-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Accepted: 08/03/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The aim of this study was to probe cardiac complications, including heart-rate control, in a mouse model of type-2 diabetes. Heart-rate development in diabetic patients is not straight forward: In general, patients with diabetes have faster heart rates compared to non-diabetic individuals, yet diabetic patients are frequently found among patients treated for slow heart rates. Hence, we hypothesized that sinoatrial node (SAN) dysfunction could contribute to our understanding of the mechanism behind this conundrum and the consequences thereof. METHODS Cardiac hemodynamic and electrophysiological characteristics were investigated in diabetic db/db and control db/+ mice. RESULTS We found improved contractile function and impaired filling dynamics of the heart in db/db mice, relative to db/+ controls. Electrophysiologically, we observed comparable heart rates in the two mouse groups, but SAN recovery time was prolonged in diabetic mice. Adrenoreceptor stimulation increased heart rate in all mice and elicited cardiac arrhythmias in db/db mice only. The arrhythmias emanated from the SAN and were characterized by large RR fluctuations. Moreover, nerve density was reduced in the SAN region. CONCLUSIONS Enhanced systolic function and reduced diastolic function indicates early ventricular remodeling in obese and diabetic mice. They have SAN dysfunction, and adrenoreceptor stimulation triggers cardiac arrhythmia originating in the SAN. Thus, dysfunction of the intrinsic cardiac pacemaker and remodeling of the autonomic nervous system may conspire to increase cardiac mortality in diabetic patients.
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47
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Schramm A, Jähne EA, Baburin I, Hering S, Hamburger M. Natural products as potential human ether-a-go-go-related gene channel inhibitors - outcomes from a screening of widely used herbal medicines and edible plants. Planta Med 2014; 80:1045-1050. [PMID: 25089737 DOI: 10.1055/s-0034-1382907] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Inhibition of the human ether-a-go-go-related gene channel is the single most important risk factor leading to acquired long QT syndrome. Drug-induced QT prolongation can cause severe cardiac complications, including arrhythmia, and is thus a liability in drug development. Considering the importance of the human ether-a-go-go-related gene channel as an antitarget and the daily intake of plant-derived foods and herbal products, surprisingly few natural products have been tested for channel blocking properties. In an assessment of possible human ether-a-go-go-related gene liabilities, a selection of widely used herbal medicines and edible plants (vegetables, fruits, and spices) was screened by means of a functional two-microelectrode voltage-clamp assay with Xenopus oocytes. The human ether-a-go-go-related gene channel blocking activity of selected extracts was investigated with the aid of a high-performance liquid chromatography-based profiling approach, and attributed to tannins and alkaloids. Major European medicinal plants and frequently consumed food plants were found to have a low risk for human ether-a-go-go-related gene toxicity.
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Affiliation(s)
- Anja Schramm
- Division of Pharmaceutical Biology, University of Basel, Basel, Switzerland
| | - Evelyn A Jähne
- Division of Pharmaceutical Biology, University of Basel, Basel, Switzerland
| | - Igor Baburin
- Institute of Pharmacology and Toxicology, University of Vienna, Vienna, Austria
| | - Steffen Hering
- Institute of Pharmacology and Toxicology, University of Vienna, Vienna, Austria
| | - Matthias Hamburger
- Division of Pharmaceutical Biology, University of Basel, Basel, Switzerland
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48
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Affiliation(s)
- J S Carvalho
- Brompton Centre for Fetal Cardiology, Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK; Fetal Medicine Unit, St George's Hospital, St George's University of London, London, SW17 0QT, UK.
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49
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Bai Y, Liang Y, Tan H, Qiao S, Zhang J, Yang Y, Zhang Y, Zhu J. [Clinical characteristics and prognosis comparison of Chinese non ST-segment elevation acute coronary syndrome patients in two different time periods]. Zhonghua Xin Xue Guan Bing Za Zhi 2014; 42:655-660. [PMID: 25388338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
OBJECTIVE To compare the clinical characteristics, treatment methods and outcomes in Chinese non ST-segment elevation acute coronary syndrome (NSTE-ACS) patients from two large clinical trials in different time periods. METHODS All Chinese NSTE-ACS patients from two large International clinical trials (OASIS Registry and TIMACS) underwent coronary artery angiography after first admission were recruited in our analysis. The follow-up time was 180 days. A total of 1 473 NSTE-ACS patients were recruited in this analysis, in which 749 from Organization to Assess Strategies for Ischemic Syndromes (OASIS REISTRY) that completed in 38 centers in China from April 1999 to December 2000, and the rest 724 patients from The Timing of Intervention in Acute Coronary Syndromes (TIMACS) trial in 24 centers in China performed from April 2007 to June 2008. RESULTS Compared to OASIS patients, TIMACS group were older ((64.2 ± 10.1) years old vs. (58.7 ± 10.2) years old) , and fewer male patients (66.3% (480/724) vs. 74.4% (557/749)) , lower blood pressure at admission, and more histories of previous PCI (9.4% (68/724 vs. 6.4% (48/749)), stroke (8.8% (64/724) vs. 5.1% (38/749)) , hypertension (62.8% (455/724) vs. 56.6% (424/749)) and diabetes (23.3% (169/724) vs. 16.2% (121/749)), lower histories of coronary artery disease (37.4% (271/724) vs. 59.1% (443/749)) and myocardial infarction (12.0% (87/724) vs. 27.6% (207/749)) (all P < 0.05). After admission, comparing to OASIS group, TIMACS patients had significant higher PCI proportion (74.9% (524/724) vs. 49.3% (369/749), P < 0.001). In addition, for secondary prevention, TIMACS patients had significant higher standard medication treatment proportion during hospitalization, at discharge and at 180 days follow up than OASIS group (P < 0.05 for β-blocker, ACEI/ARB and lipid lowering drugs) and higher compliance rate. The combined primary outcome event rate at 180 days was much lower in TIMACS than in OASIS patients (13.3% (96/724) vs. 25.2% (189/749), P < 0.001) mostly due to the reduction on the refractory angina (5.2% (38/724) vs. 22.6% (169/749), P < 0.001) . RESULTS of COX regression model adjusted for baseline levels and treatment during hospitalization showed that the incidence rate of combination endpoint (HR = 0.39, 95% CI: 0.29-0.53, P < 0.001) and refractory ischemia/angina rehospitalization (HR = 0.17, 95% CI: 0.11-0.25, P < 0.001) were both lower in TIMACS patients than in OASIS patients. CONCLUSION PCI procedure and secondary prevention medication administration are more often applied in TIMACS patients than in OASIS group, which is related to less integrated incidence of primary outcomes reflecting progress in Chinese medical care for non ST elevated acute coronary syndrome patients according to the updated guidelines.
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Affiliation(s)
- Ying Bai
- Emergency and Intensive Care Center, Cardiovascular Institute and Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100037, China
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50
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Affiliation(s)
- Enid Gilbert-Barness
- Laboratory Medicine, Pediatric, Obstetrics and Gynecology, Department of Pathology, College of Medicine, Tampa General Hospital, University of South Florida Morsani, 1 Tampa General Circle, Tampa, FL 33606, USA.
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