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Alhourani N, Wolfes J, Könemann H, Ellermann C, Frommeyer G, Güner F, Lange PS, Reinke F, Köbe J, Eckardt L. Relevance of mexiletine in the era of evolving antiarrhythmic therapy of ventricular arrhythmias. Clin Res Cardiol 2024; 113:791-800. [PMID: 38353682 PMCID: PMC11108884 DOI: 10.1007/s00392-024-02383-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2023] [Accepted: 01/19/2024] [Indexed: 05/22/2024]
Abstract
Despite impressive developments in the field of ventricular arrhythmias, there is still a relevant number of patients with ventricular arrhythmias who require antiarrhythmic drug therapy and may, e.g., in otherwise drug and/or ablation refractory situations, benefit from agents known for decades, such as mexiletine. Through its capability of blocking fast sodium channels in cardiomyocytes, it has played a minor to moderate antiarrhythmic role throughout the recent decades. Nevertheless, certain patients with structural heart disease suffering from drug-refractory, i.e., mainly amiodarone refractory ventricular arrhythmias, as well as those with selected forms of congenital long QT syndrome (LQTS) may nowadays still benefit from mexiletine. Here, we outline mexiletine's cellular and clinical electrophysiological properties. In addition, the application of mexiletine may be accompanied by various potential side effects, e.g., nausea and tremor, and is limited by several drug-drug interactions. Thus, we shed light on the current therapeutic role of mexiletine for therapy of ventricular arrhythmias and discuss clinically relevant aspects of its indications based on current evidence.
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Affiliation(s)
- Nawar Alhourani
- Department of Cardiology II: Electrophysiology, University Hospital Münster, Münster, Germany.
| | - Julian Wolfes
- Department of Cardiology II: Electrophysiology, University Hospital Münster, Münster, Germany
| | - Hilke Könemann
- Department of Cardiology II: Electrophysiology, University Hospital Münster, Münster, Germany
| | - Christian Ellermann
- Department of Cardiology II: Electrophysiology, University Hospital Münster, Münster, Germany
| | - Gerrit Frommeyer
- Department of Cardiology II: Electrophysiology, University Hospital Münster, Münster, Germany
| | - Fatih Güner
- Department of Cardiology II: Electrophysiology, University Hospital Münster, Münster, Germany
| | - Philipp Sebastian Lange
- Department of Cardiology II: Electrophysiology, University Hospital Münster, Münster, Germany
| | - Florian Reinke
- Department of Cardiology II: Electrophysiology, University Hospital Münster, Münster, Germany
| | - Julia Köbe
- Department of Cardiology II: Electrophysiology, University Hospital Münster, Münster, Germany
| | - Lars Eckardt
- Department of Cardiology II: Electrophysiology, University Hospital Münster, Münster, Germany
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2
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van der Ree MH, van Dussen L, Rosenberg N, Stolwijk N, van den Berg S, van der Wel V, Jacobs BAW, Wilde AAM, Hollak CEM, Postema PG. Effectiveness and safety of mexiletine in patients at risk for (recurrent) ventricular arrhythmias: a systematic review. Europace 2022; 24:1809-1823. [PMID: 36036670 DOI: 10.1093/europace/euac087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 05/12/2022] [Indexed: 11/15/2022] Open
Abstract
While mexiletine has been used for over 40 years for prevention of (recurrent) ventricular arrhythmias and for myotonia, patient access has recently been critically endangered. Here we aim to demonstrate the effectiveness and safety of mexiletine in the treatment of patients with (recurrent) ventricular arrhythmias, emphasizing the absolute necessity of its accessibility. Studies were included in this systematic review (PROSPERO, CRD42020213434) if the efficacy or safety of mexiletine in any dose was evaluated in patients at risk for (recurrent) ventricular arrhythmias with or without comparison with alternative treatments (e.g. placebo). A systematic search was performed in Ovid MEDLINE, Embase, and in the clinical trial registry databases ClinicalTrials.gov and ICTRP. Risk of bias were assessed and tailored to the different study designs. Large heterogeneity in study designs and outcome measures prompted a narrative synthesis approach. In total, 221 studies were included reporting on 8970 patients treated with mexiletine. Age ranged from 0 to 88 years. A decrease in ventricular arrhythmias of >50% was observed in 72% of the studies for pre-mature ventricular complexes, 64% for ventricular tachycardia, and 33% for ventricular fibrillation. Electrocardiographic effects of mexiletine were small; only in a subset of patients with primary arrhythmia syndromes, a relative (desired) QTc decrease was reproducibly observed. As for adverse events, gastrointestinal complaints were most frequently observed (33% of the patients). In this systematic review, we present all the currently available knowledge of mexiletine in patients at risk for (recurrent) ventricular arrhythmias and show that mexiletine is both effective and safe.
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Affiliation(s)
- Martijn H van der Ree
- Department of Clinical Cardiology, Heart Center, Amsterdam UMC-University of Amsterdam, Cardiovascular Sciences, Meibergdreef 9, Amsterdam, The Netherlands
| | - Laura van Dussen
- Department of Endocrinology and Metabolism, Amsterdam UMC-University of Amsterdam, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands
- Medicine for Society, Platform at Amsterdam UMC-University of Amsterdam, Amsterdam, The Netherlands
| | - Noa Rosenberg
- Department of Endocrinology and Metabolism, Amsterdam UMC-University of Amsterdam, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands
- Medicine for Society, Platform at Amsterdam UMC-University of Amsterdam, Amsterdam, The Netherlands
| | - Nina Stolwijk
- Department of Endocrinology and Metabolism, Amsterdam UMC-University of Amsterdam, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands
- Medicine for Society, Platform at Amsterdam UMC-University of Amsterdam, Amsterdam, The Netherlands
| | - Sibren van den Berg
- Department of Endocrinology and Metabolism, Amsterdam UMC-University of Amsterdam, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands
- Medicine for Society, Platform at Amsterdam UMC-University of Amsterdam, Amsterdam, The Netherlands
| | - Vincent van der Wel
- Medicine for Society, Platform at Amsterdam UMC-University of Amsterdam, Amsterdam, The Netherlands
| | - Bart A W Jacobs
- Medicine for Society, Platform at Amsterdam UMC-University of Amsterdam, Amsterdam, The Netherlands
- Department of Pharmacy, Amsterdam UMC-University of Amsterdam, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands
| | - Arthur A M Wilde
- Department of Clinical Cardiology, Heart Center, Amsterdam UMC-University of Amsterdam, Cardiovascular Sciences, Meibergdreef 9, Amsterdam, The Netherlands
| | - Carla E M Hollak
- Department of Endocrinology and Metabolism, Amsterdam UMC-University of Amsterdam, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands
- Medicine for Society, Platform at Amsterdam UMC-University of Amsterdam, Amsterdam, The Netherlands
| | - Pieter G Postema
- Department of Clinical Cardiology, Heart Center, Amsterdam UMC-University of Amsterdam, Cardiovascular Sciences, Meibergdreef 9, Amsterdam, The Netherlands
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3
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Farkowski MM, Karlinski M, Pytkowski M, de Asmundis C, Lewandowski M, Mugnai G, Conte G, Marijon E, Anic A, Boveda S, Providencia R. Mexiletine for recurrent ventricular tachycardia in adult patients with structural heart disease and implantable cardioverter defibrillator: an EHRA systematic review. Europace 2022; 24:1504-1511. [DOI: 10.1093/europace/euac101] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 05/26/2022] [Indexed: 11/13/2022] Open
Abstract
Abstract
The aim of the study was to systematically review evidence on the effectiveness and safety of oral mexiletine administered in monotherapy or in combination with other antiarrhythmic drugs for recurrent ventricular arrhythmia (ventricular tachycardia/ventricular fibrillation, VT/VF) in adult patients with structural heart disease (SHD) and implantable cardioverter defibrillators (ICDs). We systematically searched MEDLINE, Embase, and CENTRAL databases from inception to 27 August 2021 for prospective and retrospective studies investigating mexiletine in the target population. The main outcome was the reduction of ICD therapy. The main safety outcome was the presence of any serious adverse events (SAEs) leading to mexiletine discontinuation. Study quality was assessed using the Cochrane risk of bias tool or the Newcastle–Ottawa scale. Four studies comprising 86 mexiletine recipients were included in the review. We also obtained individual data of 50 patients from two studies. Ischaemic cardiomyopathy (ICM) was present in 86% of patients. The quality of included studies was moderate/low. A narrative review was undertaken as studies varied widely in terms of study population and treatment. Across studies, mexiletine treatment (with or without amiodarone) seemed to consistently reduce the number of ICD therapies especially in a population where catheter ablation (CA) was unsuccessful or contraindicated. In ICM patients deemed eligible for CA, mexiletine seemed to be inferior to CA. Mexiletine was discontinued in 14% of cases, mainly for gastrointestinal or neurological SAE. Mexiletine seems to be an option for the long-term treatment of recurrent VT/VF in adult patients with SHD, especially ICM, and ICD in whom CA was unsuccessful or not suitable.
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Affiliation(s)
- Michal Miroslaw Farkowski
- II Department of Heart Arrhythmia, National Institute of Cardiology , Alpejska 42, 04-628 Warsaw , Poland
| | - Michal Karlinski
- II Department of Neurology, Institute of Psychiatry and Neurology , Warsaw , Poland
| | - Mariusz Pytkowski
- II Department of Heart Arrhythmia, National Institute of Cardiology , Alpejska 42, 04-628 Warsaw , Poland
| | - Carlo de Asmundis
- Heart Rhythm Management Centre, Universitair Ziekenhuis Brussel—Vrije Universiteit Brussel , Brussels , Belgium
| | - Michal Lewandowski
- II Department of Heart Arrhythmia, National Institute of Cardiology , Alpejska 42, 04-628 Warsaw , Poland
| | - Giacomo Mugnai
- Division of Cardiology, West Vicenza General Hospitals , Arzignano (Vicenza) , Italy
- Division of Cardiology, Department of Medicine, University Hospital of Verona , Verona , Italy
| | - Giulio Conte
- Cardiology Department, Cardiocentro Ticino Institute , Lugano , Switzerland
| | - Eloi Marijon
- Département de Cardiologie, Université Paris-Descartes, Hôpital Européen Georges Pompidou , Paris , France
| | - Ante Anic
- Department of Cardiology, University Clinical Hospital Split , Split , Croatia
| | - Serge Boveda
- Heart Rhythm Management Centre, Universitair Ziekenhuis Brussel—Vrije Universiteit Brussel , Brussels , Belgium
- Heart Rhythm Management Department, Clinique Pasteur , Toulouse , France
| | - Rui Providencia
- St Bartholomew’s Hospital, Barts Heart Centre, Barts Health NHS Trust , London , UK
- Institute of Health Informatics, University College of London , London , UK
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4
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Hesketh LM, Sikkel MB, Mahoney-Sanchez L, Mazzacuva F, Chowdhury RA, Tzortzis KN, Firth J, Winter J, MacLeod KT, Ogrodzinski S, Wilder CDE, Patterson LH, Peters NS, Curtis MJ. OCT2013, an ischaemia-activated antiarrhythmic prodrug, devoid of the systemic side effects of lidocaine. Br J Pharmacol 2022; 179:2037-2053. [PMID: 34855992 DOI: 10.1111/bph.15764] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 09/28/2021] [Accepted: 11/04/2021] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND AND PURPOSE Sudden cardiac death (SCD) caused by acute myocardial ischaemia and ventricular fibrillation (VF) is an unmet therapeutic need. Lidocaine suppresses ischaemia-induced VF, but its utility is limited by side effects and a narrow therapeutic index. Here, we characterise OCT2013, a putative ischaemia-activated prodrug of lidocaine. EXPERIMENTAL APPROACH The rat Langendorff-perfused isolated heart, anaesthetised rat and rat ventricular myocyte preparations were utilised in a series of blinded and randomised studies to investigate the antiarrhythmic effectiveness, adverse effects and mechanism of action of OCT2013, compared with lidocaine. KEY RESULTS In isolated hearts, OCT2013 and lidocaine prevented ischaemia-induced VF equi-effectively, but OCT2013 did not share lidocaine's adverse effects (PR widening, bradycardia and negative inotropy). In anaesthetised rats, i.v. OCT2013 and lidocaine suppressed VF and increased survival equi-effectively; OCT2013 had no effect on cardiac output even at 64 mg·kg-1 i.v., whereas lidocaine reduced it even at 1 mg·kg-1 . In adult rat ventricular myocytes, OCT2013 had no effect on Ca2+ handling, whereas lidocaine impaired it. In paced isolated hearts, lidocaine caused rate-dependent conduction slowing and block, whereas OCT2013 was inactive. However, during regional ischaemia, OCT2013 and lidocaine equi-effectively hastened conduction block. Chromatography and MS analysis revealed that OCT2013, detectable in normoxic OCT2013-perfused hearts, became undetectable during global ischaemia, with lidocaine becoming detectable. CONCLUSIONS AND IMPLICATIONS OCT2013 is inactive but is bio-reduced locally in ischaemic myocardium to lidocaine, acting as an ischaemia-activated and ischaemia-selective antiarrhythmic prodrug with a large therapeutic index, mimicking lidocaine's benefit without adversity.
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Affiliation(s)
- Louise M Hesketh
- Cardiovascular Division, Faculty of Life Sciences and Medicine, The Rayne Institute, St Thomas' Hospital, King's College London, London, UK
| | - Markus B Sikkel
- National Heart and Lung Institute, Faculty of Medicine, ICTEM, The Hammersmith Hospital, Imperial College London, London, UK
| | - Laura Mahoney-Sanchez
- Cardiovascular Division, Faculty of Life Sciences and Medicine, The Rayne Institute, St Thomas' Hospital, King's College London, London, UK
| | | | - Rasheda A Chowdhury
- National Heart and Lung Institute, Faculty of Medicine, ICTEM, The Hammersmith Hospital, Imperial College London, London, UK
| | - Konstantinos N Tzortzis
- National Heart and Lung Institute, Faculty of Medicine, ICTEM, The Hammersmith Hospital, Imperial College London, London, UK
| | - Jahn Firth
- National Heart and Lung Institute, Faculty of Medicine, ICTEM, The Hammersmith Hospital, Imperial College London, London, UK
| | - James Winter
- Cardiovascular Division, Faculty of Life Sciences and Medicine, The Rayne Institute, St Thomas' Hospital, King's College London, London, UK
| | - Kenneth T MacLeod
- National Heart and Lung Institute, Faculty of Medicine, ICTEM, The Hammersmith Hospital, Imperial College London, London, UK
| | | | - Catherine D E Wilder
- Cardiovascular Division, Faculty of Life Sciences and Medicine, The Rayne Institute, St Thomas' Hospital, King's College London, London, UK
| | | | - Nicholas S Peters
- National Heart and Lung Institute, Faculty of Medicine, ICTEM, The Hammersmith Hospital, Imperial College London, London, UK
| | - Michael J Curtis
- Cardiovascular Division, Faculty of Life Sciences and Medicine, The Rayne Institute, St Thomas' Hospital, King's College London, London, UK
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5
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Abstract
Purpose of Review Optimal timing for catheter ablation of ventricular tachycardia is an important yet unresolved subject. While it is clear that it is indicated with relatively advanced disease, it is still uncertain how early it should be recommended. In this review, we will focus on the status of timing of catheter ablation for VT in patients with ICD therapies. Recent Findings The latest expert consensus statement added a new timing indication for catheter ablation after the first episode of monomorphic VT, in patients with ischemic heart disease and an ICD. Summary Early referral for catheter ablation reduces the number of VT recurrences; however, an impact on mortality has not been demonstrated yet. Guidelines and real-world data alike show an increasing trend to refer patients after the first VT episode in ICD patients. Randomized clinical trials powered to assess mortality are essential in order confirm the beneficial effects of an early strategy.
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6
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Deyell MW, AbdelWahab A, Angaran P, Essebag V, Glover B, Gula LJ, Khoo C, Lane C, Nault I, Nery PB, Rivard L, Slawnych MP, Tulloch HL, Sapp JL. 2020 Canadian Cardiovascular Society/Canadian Heart Rhythm Society Position Statement on the Management of Ventricular Tachycardia and Fibrillation in Patients With Structural Heart Disease. Can J Cardiol 2020; 36:822-836. [DOI: 10.1016/j.cjca.2020.04.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 03/29/2020] [Accepted: 04/05/2020] [Indexed: 10/24/2022] Open
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Hesketh LM, Wilder CDE, Ranadive NN, Lytra G, Qazimi P, Munro JS, Ahdi N, Curtis MJ. Characterisation of mexiletine's translational therapeutic index for suppression of ischaemia-induced ventricular fibrillation in the rat isolated heart. Sci Rep 2020; 10:8397. [PMID: 32439959 PMCID: PMC7242333 DOI: 10.1038/s41598-020-65190-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 04/24/2020] [Indexed: 11/09/2022] Open
Abstract
The 'translational therapeutic index' (TTI) is a drug's ratio of nonclinical threshold dose (or concentration) for significant benefit versus threshold for adversity. In early nonclinical research, discovery and safety studies are normally undertaken separately. Our aim was to evaluate a novel integrated approach for generating a TTI for drugs intended for prevention of ischaemia-induced ventricular fibrillation (VF). We templated the current best available class 1b antiarrhythmic, mexiletine, using the rat Langendorff preparation. Mexiletine's beneficial effects on the incidence of VF caused by 120 min regional ischaemia were contrasted with its concurrent adverse effects (on several variables) in the same hearts, to generate a TTI. Mexiletine 0.1 and 0.5 µM had no adverse effects, but did not reduce VF incidence. Mexiletine 1 µM reduced VF incidence to 0% but had adverse effects on atrioventricular conduction and ventricular repolarization. Separate studies undertaken using an intraventricular balloon revealed no detrimental effects of mexiletine (1 and 5 µM) on mechanical function, or any benefit against reperfusion-related dysfunction. Mexiletine's TTI was found to be less than two, which accords with its clinical therapeutic index. Although non-cardiac adversity, identifiable from additional in vivo studies, may reduce the TTI further, it cannot increase it. Our experimental approach represents a useful early-stage integrated risk/benefit method that, when TTI is found to be low, would eliminate unsuitable class 1b drugs prior to next stage in vivo work, with mexiletine's TTI defining the gold standard that would need to be bettered.
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Affiliation(s)
- Louise M Hesketh
- Cardiovascular Division, Faculty of Life Sciences and Medicine, The Rayne Institute, King's College London, St Thomas' Hospital, London, SE1 7EH, UK
| | - Catherine D E Wilder
- Cardiovascular Division, Faculty of Life Sciences and Medicine, The Rayne Institute, King's College London, St Thomas' Hospital, London, SE1 7EH, UK
| | - Niraja N Ranadive
- Cardiovascular Division, Faculty of Life Sciences and Medicine, The Rayne Institute, King's College London, St Thomas' Hospital, London, SE1 7EH, UK
| | - Georgia Lytra
- Cardiovascular Division, Faculty of Life Sciences and Medicine, The Rayne Institute, King's College London, St Thomas' Hospital, London, SE1 7EH, UK
| | - Patrisia Qazimi
- Cardiovascular Division, Faculty of Life Sciences and Medicine, The Rayne Institute, King's College London, St Thomas' Hospital, London, SE1 7EH, UK
| | - Jade S Munro
- Cardiovascular Division, Faculty of Life Sciences and Medicine, The Rayne Institute, King's College London, St Thomas' Hospital, London, SE1 7EH, UK
| | - Nakita Ahdi
- Cardiovascular Division, Faculty of Life Sciences and Medicine, The Rayne Institute, King's College London, St Thomas' Hospital, London, SE1 7EH, UK
| | - Michael J Curtis
- Cardiovascular Division, Faculty of Life Sciences and Medicine, The Rayne Institute, King's College London, St Thomas' Hospital, London, SE1 7EH, UK.
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8
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Zhu W, Mazzanti A, Voelker TL, Hou P, Moreno JD, Angsutararux P, Naegle KM, Priori SG, Silva JR. Predicting Patient Response to the Antiarrhythmic Mexiletine Based on Genetic Variation. Circ Res 2019; 124:539-552. [PMID: 30566038 DOI: 10.1161/circresaha.118.314050] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
RATIONALE Mutations in the SCN5A gene, encoding the α subunit of the Nav1.5 channel, cause a life-threatening form of cardiac arrhythmia, long QT syndrome type 3 (LQT3). Mexiletine, which is structurally related to the Na+ channel-blocking anesthetic lidocaine, is used to treat LQT3 patients. However, the patient response is variable, depending on the genetic mutation in SCN5A. OBJECTIVE The goal of this study is to understand the molecular basis of patients' variable responses and build a predictive statistical model that can be used to personalize mexiletine treatment based on patient's genetic variant. METHODS AND RESULTS We monitored the cardiac Na+ channel voltage-sensing domain (VSD) conformational dynamics simultaneously with other gating properties for the LQT3 variants. To systematically identify the relationship between mexiletine block and channel biophysical properties, we used a system-based statistical modeling approach to connect the multivariate properties to patient phenotype. We found that mexiletine altered the conformation of the Domain III VSD, which is the same VSD that many tested LQT3 mutations affect. Analysis of 15 LQT3 variants showed a strong correlation between the activation of the Domain III-VSD and the strength of the inhibition of the channel by mexiletine. Based on this improved molecular-level understanding, we generated a systems-based model based on a dataset of 32 LQT3 patients, which then successfully predicted the response of 7 out of 8 patients to mexiletine in a blinded, retrospective trial. CONCLUSIONS Our results imply that the modulated receptor theory of local anesthetic action, which confines local anesthetic binding effects to the channel pore, should be revised to include drug interaction with the Domain III-VSD. Using an algorithm that incorporates this mode of action, we can predict patient-specific responses to mexiletine, improving therapeutic decision making.
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Affiliation(s)
- Wandi Zhu
- From the Department of Biomedical Engineering (W.Z., T.L.V., P.H., J.D.M., P.A., K.M.N., J.R.S.), Washington University in St Louis, MO
| | - Andrea Mazzanti
- Molecular Cardiology, IRCCS Salvatore Maugeri Foundation, Pavia, Italy (A.M., S.G.P.)
| | - Taylor L Voelker
- From the Department of Biomedical Engineering (W.Z., T.L.V., P.H., J.D.M., P.A., K.M.N., J.R.S.), Washington University in St Louis, MO
| | - Panpan Hou
- From the Department of Biomedical Engineering (W.Z., T.L.V., P.H., J.D.M., P.A., K.M.N., J.R.S.), Washington University in St Louis, MO
| | - Jonathan D Moreno
- From the Department of Biomedical Engineering (W.Z., T.L.V., P.H., J.D.M., P.A., K.M.N., J.R.S.), Washington University in St Louis, MO.,Division of Cardiology, Department of Medicine (J.D.M.), Washington University in St Louis, MO
| | - Paweorn Angsutararux
- From the Department of Biomedical Engineering (W.Z., T.L.V., P.H., J.D.M., P.A., K.M.N., J.R.S.), Washington University in St Louis, MO
| | - Kristen M Naegle
- From the Department of Biomedical Engineering (W.Z., T.L.V., P.H., J.D.M., P.A., K.M.N., J.R.S.), Washington University in St Louis, MO
| | - Silvia G Priori
- Molecular Cardiology, IRCCS Salvatore Maugeri Foundation, Pavia, Italy (A.M., S.G.P.).,Department of Molecular Medicine, University of Pavia, Italy (S.G.P.)
| | - Jonathan R Silva
- From the Department of Biomedical Engineering (W.Z., T.L.V., P.H., J.D.M., P.A., K.M.N., J.R.S.), Washington University in St Louis, MO
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9
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Deyell MW, Steinberg C, Doucette S, Parkash R, Nault I, Gray C, Essebag V, Gardner M, Sterns LD, Healey JS, Hruczkowski T, Rivard L, Leong-Sit P, Nery PB, Sapp JL. Mexiletine or catheter ablation after amiodarone failure in the VANISH trial. J Cardiovasc Electrophysiol 2018; 29:603-608. [DOI: 10.1111/jce.13431] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 01/09/2018] [Accepted: 01/10/2018] [Indexed: 01/25/2023]
Affiliation(s)
- Marc W. Deyell
- Heart Rhythm Services, Division of Cardiology, Department of Medicine; University of British Columbia; Vancouver British Columbia Canada
| | - Christian Steinberg
- Institut Universitaire de Cardiologie et Pneumologie de Québec; Universite Laval; Quebec City Quebec Canada
| | - Steve Doucette
- Department of Medicine; QEII Health Sciences Centre and Dalhousie University; Halifax Nova Scotia Canada
| | - Ratika Parkash
- Department of Medicine; QEII Health Sciences Centre and Dalhousie University; Halifax Nova Scotia Canada
| | - Isabelle Nault
- Institut Universitaire de Cardiologie et Pneumologie de Québec; Universite Laval; Quebec City Quebec Canada
| | - Chris Gray
- Department of Medicine; QEII Health Sciences Centre and Dalhousie University; Halifax Nova Scotia Canada
| | - Vidal Essebag
- McGill University Health Centre and Hôpital Sacré-Coeur de Montréal; Montreal Quebec Canada
| | - Martin Gardner
- Department of Medicine; QEII Health Sciences Centre and Dalhousie University; Halifax Nova Scotia Canada
| | | | - Jeff S. Healey
- Population Health Research Institute; Hamilton Ontario Canada
| | - Tomasz Hruczkowski
- Mazankowski Alberta Heart Institute; University of Alberta; Edmonton Alberta Canada
| | - Lena Rivard
- Institut de Cardiologie de Montréal; Montreal Quebec Canada
| | - Peter Leong-Sit
- Heart Rhythm Service, University Hospital; Western University; London Ontario Canada
| | - Pablo B. Nery
- University of Ottawa Heart Institute; Ottawa Ontario Canada
| | - John L. Sapp
- Department of Medicine; QEII Health Sciences Centre and Dalhousie University; Halifax Nova Scotia Canada
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10
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AL-KHATIB SANAM, DAUBERT JAMESP, ANSTROM KEVINJ, DAOUD EMILEG, GONZALEZ MARIO, SABA SAMIR, JACKSON KEVINP, REECE TAMMY, GU JOAN, POKORNEY SEAND, GRANGER CHRISTOPHERB, HESS PAULL, MARK DANIELB, STEVENSON WILLIAMG. Catheter Ablation for Ventricular Tachycardia in Patients with an Implantable Cardioverter Defibrillator (CALYPSO) Pilot Trial. J Cardiovasc Electrophysiol 2014; 26:151-7. [DOI: 10.1111/jce.12567] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Revised: 09/30/2014] [Accepted: 10/13/2014] [Indexed: 11/29/2022]
Affiliation(s)
- SANA M. AL-KHATIB
- Department of Medicine; Duke Clinical Research Institute; Duke University Medical Center; Durham North Carolina
- Division of Cardiology; Department of Medicine; Duke University Medical Center; Durham North Carolina
| | - JAMES P. DAUBERT
- Department of Medicine; Duke Clinical Research Institute; Duke University Medical Center; Durham North Carolina
- Division of Cardiology; Department of Medicine; Duke University Medical Center; Durham North Carolina
| | - KEVIN J. ANSTROM
- Department of Medicine; Duke Clinical Research Institute; Duke University Medical Center; Durham North Carolina
| | - EMILE G. DAOUD
- Division of Cardiology; Wexner Medical Center at the Ohio State University; Columbus Ohio
| | - MARIO GONZALEZ
- Division of Cardiology; Pennsylvania State University; State College Pennsylvania
| | - SAMIR SABA
- Division of Cardiology; University of Pittsburgh; Pittsburgh Pennsylvania
| | - KEVIN P. JACKSON
- Division of Cardiology; Department of Medicine; Duke University Medical Center; Durham North Carolina
| | - TAMMY REECE
- Department of Medicine; Duke Clinical Research Institute; Duke University Medical Center; Durham North Carolina
| | - JOAN GU
- Department of Medicine; Duke Clinical Research Institute; Duke University Medical Center; Durham North Carolina
| | - SEAN D. POKORNEY
- Department of Medicine; Duke Clinical Research Institute; Duke University Medical Center; Durham North Carolina
- Division of Cardiology; Department of Medicine; Duke University Medical Center; Durham North Carolina
| | - CHRISTOPHER B. GRANGER
- Department of Medicine; Duke Clinical Research Institute; Duke University Medical Center; Durham North Carolina
- Division of Cardiology; Department of Medicine; Duke University Medical Center; Durham North Carolina
| | - PAUL L. HESS
- Division of Cardiology; Department of Medicine; Duke University Medical Center; Durham North Carolina
| | - DANIEL B. MARK
- Department of Medicine; Duke Clinical Research Institute; Duke University Medical Center; Durham North Carolina
- Division of Cardiology; Department of Medicine; Duke University Medical Center; Durham North Carolina
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Antiarrhythmic Effects and Tolerability of Mexiletine in Patients with Suspected Acute Myocardial Infarction. ACTA ACUST UNITED AC 2012. [DOI: 10.1007/bf03258245] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Boriani G, Diemberger I, Valzania C, Biffi M, Martignani C, Raschi E, Mantovani V, Ziacchi M, Bertini M, De Ponti F, Branzi A. Role of drugs and devices in patients at risk of sudden cardiac death. Fundam Clin Pharmacol 2010; 24:575-94. [DOI: 10.1111/j.1472-8206.2010.00853.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Abstract
Underlying causes of ventricular tachycardia (VT) or complex ventricular arrhythmias (VA) should be treated if possible. Antiarrhythmic drugs should not be administered to treat asymptomatic individuals with complex VA and no heart disease. Beta-blockers are the only antiarrhythmic drugs that have been documented to reduce mortality in patients with VT or complex VA. Radiofrequency catheter ablation of VT has been beneficial in treating selected patients with arrhythmogenic foci of monomorphic VT. The automatic implantable cardioverter-defibrillator (AICD) is the most effective treatment for patients with life-threatening VT or ventricular fibrillation. Patients with AICDs should be treated with biventricular pacing, not with dual-chamber rate-responsive pacing at a rate of 70/min. Patients with AICDs should also be treated with beta-blockers, statins, and angiotensin-converting enzyme inhibitors or angiotensin blockers.
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Naccarelli GV, Wolbrette DL, Dell'Orfano JT, Patel HM, Luck JC. Amiodarone: what have we learned from clinical trials? Clin Cardiol 2009; 23:73-82. [PMID: 10676597 PMCID: PMC6655150 DOI: 10.1002/clc.4960230203] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Amiodarone is an antiarrhythmic agent commonly used in the treatment of supraventricular and ventricular tachyarrhythmias. This paper reviews clinical trials in which amiodarone was used in one of the treatment arms. Key post-myocardial infarction trials include EMIAT and CAMIAT, both of which demonstrated that amiodarone reduced arrhythmic but not overall mortality. In patients with congestive heart failure (CHF), amiodarone was associated with a neutral survival in CHF/STAT and improvement in survival in GESICA. In patients with nonsustained ventricular tachycardia, the MADIT trial demonstrated that therapy with an implantable cardioverter-defibrillator (ICD) improved survival compared with the antiarrhythmic drug arm in such patients, most of whom were taking amiodarone. In sustained VT/VF patients, the CASCADE trial demonstrated that empiric amiodarone lowered arrhythmic recurrence rates compared with other drugs guided by serial Holter or electrophysiologic studies. Several trials including AVID, CIDS, and CASH have demonstrated the superiority of ICD therapy compared with empiric amiodarone in improving overall survival. Clinical implications of these trials are discussed.
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Affiliation(s)
- G V Naccarelli
- Section of Cardiology, Penn State University College of Medicine, Milton S. Hershey Medical Center, PennState Geisinger Health System, Hershey 17033, USA
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KOWEY PETERR, MARINCHAK ROGERA, RIALS SETHJ. The Cardiac Arrhythmia Suppression Trial: How Has it Impacted on Contemporary Arrhythmia Management? J Cardiovasc Electrophysiol 2008. [DOI: 10.1111/j.1540-8167.1990.tb01078.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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SALERNO DAVIDM. CLASS IA AND CLASS IB ANTIARRHYTHMIC DRUGS - A Review of Their Pharmacokinetics, Electrophysiology, Efficacy, and Toxicity. J Cardiovasc Electrophysiol 2008. [DOI: 10.1111/j.1540-8167.1990.tb01697.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Abstract
The concept that antiarrhythmic drugs can exacerbate the cardiac rhythm disturbance being treated, or generate entirely new clinical arrhythmia syndromes, is not new. Abnormal cardiac rhythms due to digitalis or quinidine have been recognized for decades. This phenomenon, termed "proarrhythmia," was generally viewed as a clinical curiosity, since it was thought to be rare and unpredictable. However, the past 20 years have seen the recognition that proarrhythmia is more common than previously appreciated in certain populations, and can in fact lead to substantially increased mortality during long-term antiarrhythmic therapy. These findings, in turn, have moved proarrhythmia from a clinical curiosity to the centerpiece of antiarrhythmic drug pharmacology in at least two important respects. First, clinicians now select antiarrhythmic drug therapy in a particular patient not simply to maximize efficacy, but very frequently to minimize the likelihood of proarrhythmia. Second, avoiding proarrhythmia has become a key element of contemporary new antiarrhythmic drug development. Further, recognition of the magnitude of the problem has led to important advances in understanding basic mechanisms. While the phenomenon of proarrhythmia remains unpredictable in an individual patient, it can no longer be viewed as "idiosyncratic." Rather, gradations of risk can be assigned based on the current understanding of mechanisms, and these will doubtless improve with ongoing research at the genetic, molecular, cellular, whole heart, and clinical levels.
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Affiliation(s)
- D M Roden
- Division of Clinical Pharmacology, Vanderbilt University School of Medicine, 532 Medical Research Building I, Nashville, TN 37232, USA.
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Sassi R, Cerutti S, Hnatkova K, Malik M, Signorini MG. HRV Scaling Exponent Identifies Postinfarction Patients Who Might Benefit From Prophylactic Treatment With Amiodarone. IEEE Trans Biomed Eng 2006; 53:103-10. [PMID: 16402609 DOI: 10.1109/tbme.2005.859806] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Analysing the Holter recordings collected at baseline during the European Myocardial Infarction Amiodarone Trial (EMIAT), we evaluate the possibility of using alpha, the slope of the power spectrum of heart rate variability signals (HRV) in the vicinity of f = 0, for postinfarction risk stratification. We found no relevant difference in the values of alpha for the placebo population. On the contrary, in the amiodarone arm, the distinction in the survival rates of those with high or low alpha-values was highly significant. Moreover, high risk patients with respect to alpha (higher values) did not seem to benefit from amiodarone. The results suggest that alpha might convey physiologic information that is different than what is expressed by other HRV characteristics, such as the triangular index. When combining high risk patients in term of triangular index (<20) and low risk patients with respect to alpha (<median), the difference in survival on placebo and amiodarone became very substantial (24.2% mortality on placebo, 8.7% on amiodarone, p = 0.017). This might offer a possibility of selecting patients likely to benefit from a prophylactic antiarrhythmic treatment after acute myocardial infarction.
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Affiliation(s)
- Roberto Sassi
- Dipartimento di Bioingegneria, Politecnico di Milano, Italy.
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Yamauchi M, Watanabe E, Yasui K, Takeuchi H, Terasawa T, Sawada K, Hishida H, Kodama I. Prevention of ventricular extrasystole by mexiletine in patients with normal QT intervals is associated with a reduction of transmural dispersion of repolarization. Int J Cardiol 2005; 103:92-7. [PMID: 16061129 DOI: 10.1016/j.ijcard.2004.09.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2004] [Accepted: 09/04/2004] [Indexed: 11/21/2022]
Abstract
BACKGROUND Antiarrhythmic potential of mexiletine in patients with congenital and acquired long-QT syndrome (LQTS) has been attributed to a reduction of transmural dispersion of repolarization (TDR). A similar mechanism could be involved in the antiarrhythmic activity of the drug in patients with normal QT intervals, but the issue remains to be investigated. METHODS AND RESULTS We analyzed 24-h Holter ECG recordings from 17 patients in sinus rhythm showing premature ventricular complexes (PVCs) with normal QT intervals (age, 62+/-10 years, mean+/-S.D.). Treatment of the patients with oral mexiletine (300 mg/day for 21-40 days) resulted in a significant reduction of PVCs (from 13899+/-18887 to 6949+/-12822 beats/24 h, p<0.01). Rate-dependent behavior of ventricular repolarization was analyzed by plotting QT intervals (QT(peak), QT(end)), and the interval from T-wave peak to T-wave end (TPE) against preceding respective RR intervals of sinus beats. Both the QT(peak) and QT(end) tended to be shortened by mexiletine at RR intervals from 600 ms to 1000 ms, although the changes did not reach statistical significances. TPE, which reflects TDR, was shortened significantly at relatively long RR intervals (by 14+/-9% at RR of 900 ms, p<0.05). There was a linear relationship between the percentage shortening of TPE and the percentage reduction of PVCs (r=0.86, p<0.04). TPE> or =70 ms was significantly associated with PVC suppression >75% with an odds ratio of 0.60 (95% confidence interval 0.36-0.98, per 1 ms increment). CONCLUSION Inhibitory effect of mexiletine against PVCs in patients with normal QT intervals is mediated at least in part by a reduction of TDR. Mexiletine may be effective in patients exhibiting longer baseline TPE.
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Affiliation(s)
- Masaki Yamauchi
- Department of Cardiology, Gifu Shakai Hoken Hospital, Kani, Japan
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Yadav AV, Zipes DP. Prophylactic lidocaine in acute myocardial infarction: resurface or reburial? Am J Cardiol 2004; 94:606-8. [PMID: 15342291 DOI: 10.1016/j.amjcard.2004.05.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2004] [Revised: 05/18/2004] [Accepted: 05/18/2004] [Indexed: 11/25/2022]
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Bossard N, Boissel FH, Boissel JP. Level of evidence and therapeutic evaluation: need for more thoughts. Fundam Clin Pharmacol 2004; 18:365-72. [PMID: 15147289 DOI: 10.1111/j.1472-8206.2004.00240.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The practice of evidence-based medicine requires a tool to assess and discriminate available data based on objective grounds, thus facilitating access to reliable information. The level of evidence, conceptually and practically embedded in scientific activity, allows comparing the results from multiple studies testing an identical hypothesis along the lines of at least two dimensions. The first dimension deals with the design of the study, i.e. the extent to which bias is avoided or managed, the second with the quality of incorporated data. A third dimension specific to therapeutic evaluation focuses on the clinical relevance of the tested hypothesis. The concern of the final user of the information is thus put to the fore. Indeed, a general practitioner will be interested in the benefit for its patients whereas the concern of a biologist might significantly diverge from the former matter. The bulk of existing scales of level of evidence concentrate on methodology. Some may include the second dimension but none embrace the three of them. Seldom considered are matters regarding reproducibility and procedure. This is all the more unfortunate as reproducibility is a cornerstone of scientific progress. Moreover, scales used for overviews fail to take into account the methodology designed to produce the synthesis. Inconsistent existing scales prevent the emergence of a generally agreed standard. Therefore, there is a need to further specify the concept of level of evidence in therapy evaluation and design scales encompassing the three above-mentioned dimensions: methodology of experiment, quality of data, and clinical relevance of the primary criterion.
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Affiliation(s)
- Nadine Bossard
- Service de Biostatistique, Centre Hospitalier Lyon Sud, Lyon, France
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Adamson PB, Vanoli E, Shibano T, Foreman RD, Schwartz PJ. Combined sodium and calcium channel blockade in prevention of lethal arrhythmias. J Cardiovasc Pharmacol 2003; 41:665-70. [PMID: 12717095 DOI: 10.1097/00005344-200305000-00001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Anti-arrhythmic compounds with multiple actions reduce arrhythmic death risk in post-myocardial infarction (MI) patients. Sudden death prevention, however, may rely more on implantable defibrillators than anti-arrhythmic drugs due to ineffective pharmacologic intervention. Widespread use of implantable defibrillators should not obscure the need for development of new anti-arrhythmic drugs. This study tested the hypothesis that combined blockade of I(Na) and I(Ca(L)) prevents ischemia-dependent ventricular fibrillation (VF) in conscious dogs after MI. I(Na) and I(Ca(L)) blockade was accomplished with levosemotiadil in 11 dogs known to be at high risk for VF during 2 min of coronary occlusion during submaximal treadmill exercise 30 days after MI. Negative chronotropic effect of levosemotiadil was examined using the heart rate response to isoproterenol and comparing it with response to propranolol. Levosemotiadil prevented VF in 64% (7 of 11) of the high-risk animals. Heart rate responses to myocardial ischemia and to graded doses of isoproterenol were blunted by the high dose of levosemotiadil. Propranolol prevented VF in 73% (8 of 11) of the dogs. Levosemotiadil had approximately one half the beta-blocking activity of propranolol. The combination of I(Na) and I(Ca(L)) channel blockade coupled with partial beta-adrenergic blockade was equally effective in preventing VF as propranolol.
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Affiliation(s)
- Philip B Adamson
- Department of Physiology, Cardiovascular Diseases Section, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA.
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Singh BN. Antiarrhythmic drugs in cardiac arrest resuscitation: intravenous amiodarone or intravenous lidocaine? J Cardiovasc Pharmacol Ther 2002; 7:61-4. [PMID: 12075393 DOI: 10.1177/107424840200700201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Pugsley MK. Antiarrhythmic drug development: Historical review and future perspective. Drug Dev Res 2002. [DOI: 10.1002/ddr.10036] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Coumel P, Wilde AA. Learning from mistakes: the case of clinical electrophysiology: a perspective on evidence-based rhythmology. Circulation 2001; 104:845-7. [PMID: 11502713 DOI: 10.1161/hc3501.093338] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- P Coumel
- Department of Cardiology, Lariboisiére Hospital, Paris, France.
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Katoh T, Iinuma H, Inoue H, Ohe T, Ogawa S, Kasanuki H, Tanabe T, Hayakawa H. Multicenter prospective nonrandomized study of long-term antiarrhythmic drug therapy in patients with tachyarrhythmias: Japanese Antiarrhythmics Long-Term Study-2 (JALT-2 Study). JAPANESE CIRCULATION JOURNAL 2001; 65:275-8. [PMID: 11316122 DOI: 10.1253/jcj.65.275] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Based on the results of the Cardiac Arrhythmia Suppression Trial (CAST), strategies for the treatment of tachyarrhythmias have changed rapidly. The Japanese Antiarrhythmics Long-Term (JALT) study was planned to investigate the present methods for choosing antiarrhythmic drugs, and the effects on long-term prognosis in patients with tachyarrhythmias in Japan. Following a 6-month preliminary study (JALT-1), there was a multicenter nonrandomized prospective study (JALT-2), with a 2-year follow-up, of patients with paroxysmal atrial fibrillation (PAF), sustained ventricular tachycardia (SVT) and nonsustained VT (NSVT). Four hundred fifty-five patients were registered, and 361 of them (79%) were analyzed. Cerebral infarction occurred in 10 of 193 patients (5.2%) with PAF. Transition to chronic AF was observed in 21 patients (10.9%), but in none of the patients receiving Ca antagonist therapy. Twenty-five patients died: 5 deaths were arrhythmic, 10 were because of pump failure, and 9 were noncardiac. The most significant difference in drug selection between JALT-1 and JALT-2 was the increase in the use of slow kinetic Na channel blockers for PAF and the decrease in the use of the same agents for VT in the JALT-2 study. A marked change of therapeutic strategy occurred in JALT-2 compared with JALT-1. Most patients with a poor prognosis had underlying heart diseases and heart failure, but the per annum rate of death by arrhythmia and pump failure in JALT-2 was less than that in JALT-1.
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Affiliation(s)
- T Katoh
- First Department of Internal Medicine, Nippon Medical School, Tokyo, Japan
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Abstract
The implantable cardioverter defibrillator (ICD) represents an important development in the effort to reduce the incidence of sudden cardiac death (almost 400,000 yearly in the United States). Early generation ICDs, which required epicardial lead systems and abdominal placement of the pulse generator, have been replaced by transvenous leads and pectoral implants. Other important refinements, which include biphasic waveforms, extensive memory capability, antitachycardia pacing, and enhanced sensing algorithms, have greatly improved patient tolerance. Ongoing trials and those in the planning stages will continue to expand the indications for ICDs and will focus on cost-effectiveness.
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Affiliation(s)
- R W Peters
- Department of Medicine, Division of Cardiology, University of Maryland School of Medicine, Baltimore, Maryland, USA
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Køber L, Bloch Thomsen PE, Møller M, Torp-Pedersen C, Carlsen J, Sandøe E, Egstrup K, Agner E, Videbaek J, Marchant B, Camm AJ. Effect of dofetilide in patients with recent myocardial infarction and left-ventricular dysfunction: a randomised trial. Lancet 2000; 356:2052-8. [PMID: 11145491 DOI: 10.1016/s0140-6736(00)03402-4] [Citation(s) in RCA: 264] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
BACKGROUND Arrhythmias cause much morbidity and mortality after myocardial infarction, but in previous trials, antiarrhythmic drug therapy has not been convincingly effective. Dofetilide, a new class III agent, was investigated for effects on all-cause mortality and morbidity in patients with left-ventricular dysfunction after myocardial infarction. METHODS In 37 Danish coronary-care units, 1510 patients with severe left-ventricular dysfunction (wall motion index < or = 1.2, corresponding to ejection fraction < or = 0.35) were enrolled in a randomised, double-blind study comparing dofetilide (n=749) with placebo (n=761). The primary endpoint was all-cause mortality. Secondary endpoints included cardiac and arrhythmic mortality and total arrhythmic deaths. Analyses were by intention to treat. FINDINGS No significant differences were found between the dofetilide and placebo groups in all-cause mortality (230 [31%] vs 243 [32%]), cardiac mortality (191 [26%] vs 212 [28%]), or total arrhythmic deaths (129 [17%] vs 140 [18%]). Atrial fibrillation or flutter was present in 8% of the patients at study entry. In these patients, dofetilide was significantly better than placebo at restoring sinus rhythm (25 of 59 vs seven of 56; p=0.002). There were seven cases of torsade de pointes ventricular tachycardia, all in the dofetilide group. INTERPRETATION In patients with severe left-ventricular dysfunction and recent myocardial infarction, treatment with dofetilide did not affect all-cause mortality, cardiac mortality, or total arrhythmic deaths. Dofetilide was effective in treating atrial fibrillation or flutter in this population.
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Affiliation(s)
- L Køber
- Department of Cardiology, Gentofte University Hospital, Hellerup, Denmark.
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Maxwell S, Waring WS. Drugs used in secondary prevention after myocardial infarction: case presentation. Br J Clin Pharmacol 2000; 50:405-17. [PMID: 11069435 PMCID: PMC2014416 DOI: 10.1046/j.1365-2125.2000.00287.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Affiliation(s)
- S Maxwell
- Clinical Pharmacology Unit, The University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU.
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Abstract
Amiodarone is an antiarrhythmic agent commonly used in the treatment of supraventricular and ventricular tachyarrhythmias. This article reviews the results and clinical implications of primary and secondary prevention trials in which amiodarone was used in one of the treatment arms. Key post-myocardial infarction primary prevention trials include the European Myocardial Infarct Amiodarone Trial (EMIAT) and the Canadian Amiodarone Myocardial Infarction Trial (CAMIAT), both of which demonstrated that amiodarone reduced arrhythmic but not overall mortality. In congestive heart failure patients, amiodarone was studied as a primary prevention strategy in two pivotal trials: Grupo de Estudio de la Sobrevida en la Insuficiencia Cardiac en Argentina (GESICA) and Amiodarone in Patients With Congestive Heart Failure and Asymptomatic Ventricular Arrhythmia (CHF-STAT). Amiodarone was associated with a neutral overall survival and a trend toward improved survival in nonischemic cardiomyopathy patients in CHF/STAT and improved survival in GESICA. In post-myocardial infarction patients with nonsustained ventricular tachycardia and a depressed ejection fraction, the Multicenter Automatic Defibrillator Implantation Trial (MADIT) demonstrated that implantable cardioverter-defibrillators (ICD) statistically improved survival compared to the antiarrhythmic drug arm, most of whose patients were taking amiodarone. In patients with histories of sustained ventricular tachycardia or ventricular fibrillation, the Cardiac Arrest Study in Seattle: Conventional Versus Amiodarone Drug Evaluation (CASCADE) trial demonstrated that empiric amiodarone lowered arrhythmic recurrence rates compared to other drugs guided by serial Holter or electrophysiologic studies. However, arrhythmic death rates were high in both treatment arms of the study. Several secondary prevention trials, including the Antiarrhythmics Versus Implantable Defibrillators Study (AVID), the Canadian Implantable Defibrillator Study (CIDS), and the Cardiac Arrest Study Hamburg (CASH), have demonstrated the superiority of ICD therapy compared to empiric amiodarone in improving overall survival. Based on the above findings, amiodarone is safe to use in post-myocardial infarction and congestive heart failure patients that need antiarrhythmic therapy. Although amiodarone is effective in treating malignant arrhythmias, high-risk patients should be considered for an ICD as frontline therapy.
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Affiliation(s)
- G V Naccarelli
- Section of Cardiology and the Cardiovascular Center, Penn State University College of Medicine, Milton S. Hershey Medical Center 17033, USA
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Abstract
The high mortality rate and frequency of ventricular arrhythmias in patients with congestive heart failure has prompted numerous clinical trials aimed at reducing mortality by addressing arrhythmic death. Recently completed trials have suggested that for patients who have survived cardiac arrest, the preferred treatment may be an implantable cardioverter defibrillator (ICD). From the standpoint of primary prevention, implantable defibrillators and amiodarone have received the most attention. It remains unclear, however, to which patients these studies apply, and if and how the results might be generalized. No available studies confirm an additional benefit of pharmacologic or device-based antiarrhythmic therapy beyond that offered by optimal treatment with beta blockers, angiotensin-converting enzyme inhibitors, and lipid-lowering drugs in the majority of patients with cardiomyopathy. Clinical trials are ongoing to address these issues.
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Affiliation(s)
- A Zivin
- University of Washington Medical Center, Seattle, USA
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Abstract
Since the use of cinchona bark to treat heart palpitations in the 1700s, antiarrhythmic drug therapy has developed with the discovery of new compounds and the identification of ionic, cellular, and tissue mechanisms of action. Classifications have been developed that organize the large amount of information available about antiarrhythmic drugs around groups of compounds with common mechanisms of action. Despite important and well-recognized limitations, antiarrhythmic drug classification is still widely used. In particularly broad use is the system developed by Singh and Vaughan Williams in the early 1970s and subsequently modified by Singh and Hauswirth and by Harrison. This classification divides drug actions into class I for sodium-channel blockade (with subclasses IA, IB and IC), class II for adrenergic antagonism, class III for action-potential prolongation, and class IV for calcium-channel blockade. The development of class I drugs was curtailed when studies showed that potent sodium-channel blockers (particularly IC agents) can increase mortality in patients with active coronary artery disease. The emphasis in drug development shifted to class III agents, but their use has been limited by the risk of ventricular tachyarrhythmia induction associated with QT prolongation. Current research focuses on the development of new class III drugs that may have improved safety by virtue of greater selectivity of action at faster rates (like those of arrhythmia) or for atrial tissue. Alternative approaches include the modification of existing molecules (like amiodarone) to maintain positive properties while removing undesirable ones, and treatments that target development of the arrhythmia substrate instead of the final electrical product.
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Affiliation(s)
- S Nattel
- Department of Medicine, Montreal Heart Institute, and University of Montreal, Quebec, Canada
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Abstract
SCD continues to be an important cause of death and morbidity. Despite expanding insight into the mechanisms causing SCD, the population at high risk is not being effectively identified. Although there is still much to do in the management phase of SCD (predicting the efficacy of various therapies), recent clinical trials have helped define the relative risks and benefits of therapies in preventing SCD. Trials are underway to determine whether treating other patient populations, including asymptomatic patients after MI, will improve survival rate. The approach to reducing mortality rate will always be multifaceted; primary prevention of coronary artery disease and prompt salvage of jeopardized myocardium are 2 important aspects of this approach. In addition to interventions for MI, such as myocardial revascularization when indicated, simple and easily administered therapies that are likely to remain the most effective prophylactic interventions are aspirin, ACE inhibitors, beta-blockers, and cholesterol-lowering agents. However, the MADIT and AVID data clearly demonstrate a role for ICD therapy in a subgroup of patients who have VT/VF and are at risk of cardiac arrest. Even though the absolute magnitude of benefit associated with ICDs is still to be determined, the AVID study and other recent reports provide convincing evidence that patients who have VT/VF fare better with ICDs than with antiarrhythmic drug therapy. For the high-risk population described in this article, in addition to aggressive anti-ischemic and heart failure therapy, ICDs are now a mainstay of life-saving treatment. Still to be surmounted is the challenge of identifying patients who have nonischemic substrates and of providing them with the appropriate therapy. Guided by genetic studies and new insight into the mechanisms of such problems as congenital long QT syndrome, life-saving and life-enhancing therapies may soon be available for the management of SCD.
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Affiliation(s)
- J Sra
- University of Wisconsin Medical School, St Luke's Medical Center, Milwaukee, USA
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Abstract
OBJECTIVE To review the prognosis and management of ventricular arrhythmias (VA) in persons with and without heart disease, with emphasis on older adults. DATA SOURCES A computer-assisted search of the English language literature (MEDLINE database) followed by a manual search of the bibliographies of pertinent articles. STUDY SELECTION Studies on the prognosis and management of VA in persons with and without heart disease were screened for review. Studies in older persons and recent studies were emphasized. DATA EXTRACTION Pertinent data were extracted from the reviewed articles. Emphasis was placed on studies involving older persons. Relevant articles were reviewed in depth. DATA SYNTHESIS Available data on the prognosis and management of VA in persons with and without heart disease, with emphasis on studies in older persons, were summarized. CONCLUSIONS Ventricular arrhythmias in older persons without heart disease should not be treated with antiarrhythmic drugs, nor should Class I antiarrhythmic drugs be used to treat VA in older persons with heart disease. Beta-blockers should be used to treat complex VA in older persons with ischemic or nonischemic heart disease without contraindications to beta-blockers. Amiodarone should be reserved for life-threatening ventricular tachyarrhythmias in older persons who cannot tolerate or who do not respond to beta-blockers. Angiotensin-converting enzyme inhibitors should be used to treat older persons with heart failure, an anterior myocardial infarction, or a left ventricular ejection fraction < or = 40%. If older persons have life-threatening recurrent ventricular tachycardia (VT) or ventricular fibrillation (VF) resistant to antiarrhythmic drugs, invasive intervention should be performed. The automatic implantable cardioverter-defibrillator is recommended in older persons who have medically refractory sustained VT or VF.
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Affiliation(s)
- W S Aronow
- Hebrew Hospital Home, Bronx, New York 10475, USA
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38
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39
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Abstract
Virtually all clinical antiarrhythmic agents act by reducing ion channel conductance, with sodium (Na+), potassium (K+), and calcium (Ca++) channels the primary targets. Na+ channel blockers increase the risk of ischemic ventricular fibrillation and are relatively contraindicated in the presence of active coronary heart disease. Ca++ channel blockers suppress AV nodal conduction and are used to terminate reentrant supraventricular arrhythmias and control the ventricular response to atrial fibrillation. K+ channels constitute the most diverse group of cardiac ion channels. They are the primary targets of Class III antiarrhythmic drugs, the category of such agents presently undergoing the most active development. The rapid delayed rectifier, IKr, plays a key role in repolarization of all cardiac tissues and is the most common (and often only) target of action potential-prolonging drugs. Unfortunately, because of the ubiquity of IKr and the reverse use-dependent action potential prolongation that results from blocking it, IKr blockers are likely to cause torsades de pointes ventricular proarrhythmia. K+ channel blockers, such as amiodarone and azimilide, that affect the slow delayed rectifier IKs as well as IKr, appear to produce a more desirable rate-dependent profile of Class III action. Recently, much has been learned about the molecular basis of K+ channels based on their role in the congenital long QT syndrome. The availability of molecular clones that encode many of the channels in the human heart allows for the rapid screening of many potential new drugs, making possible the development of "designer" antiarrhythmic drugs with specific profiles of channel-blocking selectivity.
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Affiliation(s)
- S Nattel
- Research Center and Department of Medicine, Montreal Heart Institute, University of Montreal, Quebec, Canada.
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40
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Pratt CM. Predicting antiarrhythmic performance. J Cardiovasc Electrophysiol 1999; 10:302-6. [PMID: 10090236 DOI: 10.1111/j.1540-8167.1999.tb00675.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Antiarrhythmic therapy in the past was guided by observational studies. However, optimum patient care now demands evidence derived from large clinical trials. Unfortunately, because large-scale mortality trials are expensive and time consuming, surrogate markers were used in many clinical studies. However, the use of surrogate markers for antiarrhythmic drug efficacy was called into question after the publication of studies such as the Cardiac Arrhythmia Suppression Trial (CAST) and the Electrophysiologic Study Versus Electrocardiographic Monitoring (ESVEM) trial. Currently, in order to predict antiarrhythmic performance, clinicians must rely on mortality trials for guidance in treating atrial and ventricular arrhythmias. Although the practicing physician has a large number of studies to draw from, the study design and patient population are critical variables that must be understood before trial results can be applied to patient care. This review focuses on the results of the major clinical antiarrhythmic drug trials published in the last 10 years. Patient variables (e.g., the presence or absence of structural heart disease) and problems in study design that may have affected outcome are emphasized as an aid to interpreting results of current and future clinical trials.
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Affiliation(s)
- C M Pratt
- Baylor College of Medicine, Coronary Intensive Care Unit, The Methodist Hospital, Houston, Texas 77030, USA.
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41
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Campbell TJ, Williams KM. Therapeutic drug monitoring: antiarrhythmic drugs. Br J Clin Pharmacol 1998; 46:307-19. [PMID: 9803978 PMCID: PMC1874159 DOI: 10.1046/j.1365-2125.1998.t01-1-00768.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/1998] [Accepted: 04/02/1998] [Indexed: 11/20/2022] Open
Abstract
Antiarrhythmic agents are traditionally classified according to Vaughan Williams into four classes of action. Class I antiarrhythmic agents include most of the drugs traditionally thought of as antiarrhythmics, and have as a common action, blockade of the fast-inward sodium channel on myocardium. These agents have a very significant toxicity, and while they are being used less, therapeutic drug monitoring (TDM) does significantly increase the safety with which they can be administered. Class II agents are antisympathetic drugs, particularly the beta-adrenoceptor blockers. These are generally safe agents which do not normally require TDM. Class III antiarrhythmic agents include sotalol and amiodarone. TDM can be useful in the case of amiodarone to monitor compliance and toxicity but is generally of little value for sotalol. Class IV antiarrhythmic drugs are the calcium channel blockers verapamil and diltiazem. These are normally monitored by haemodynamic effects, rather than using TDM. Other agents which do not fall neatly into the Vaughan Williams classification include digoxin and perhexiline. TDM is very useful for monitoring the administration (and particularly the safety) of both of these agents.
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Affiliation(s)
- T J Campbell
- Department of Clinical Pharmacology, St Vincent's Hospital, Darlinghurst, NSW, Australia
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42
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Abstract
It is now well recognized that therapy with antiarrhythmic drugs can not only suppress cardiac arrhythmias, but also may increase their frequency or provoke new ones. Specific proarrhythmia syndromes, each with a distinct underlying mechanism and approach to therapy, have been described. The best-recognized examples are digitalis intoxication, proarrhythmia associated with sodium-channel block, and torsade de pointes occurring during QT-prolonging therapies. In the case of sodium-channel blockers, 2 forms of proarrhythmia are commonly recognized: slow atrial flutter with 1:1 atrioventricular conduction, and frequent ventricular tachycardia ([VT], most often found in patients with pre-existing VT reentrant circuits). In all cases, the best approach to therapy is to identify patients at risk (and thereby avoid therapy entirely), to recognize proarrhythmia when it occurs, to withdraw offending agent(s), and to use specific corrective therapies when available. Although most recognized episodes of proarrhythmia are thought to occur early in drug therapy, the increased mortality during chronic antiarrhythmic therapy demonstrated in large randomized trials suggests this phenomenon can also develop during long-term drug treatment. The recognition of proarrhythmia and the delineation of its underlying mechanisms should not only improve therapy with available drugs, but may also direct development of newer agents devoid of this potential.
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Affiliation(s)
- D M Roden
- Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-6602, USA
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43
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Abstract
Beta blockers have traditionally been considered relatively poor antiarrhythmic agents for patients with ventricular arrhythmias. This view is based on the observations that beta blockers are less effective in suppressing spontaneous ventricular ectopy or inducible ventricular arrhythmias than are the class I and class III agents. However, there are convincing data that beta blockers can have a clinically important antiarrhythmic effect and prevent arrhythmic and sudden death. Beta blockers have multiple potential effects that can contribute to a therapeutic antiarrhythmic action, including an antiadrenergic/vagomimetic effect, a decrease in ventricular fibrillation threshold, and prevention of a catecholamine reversal of concomitant class I/III antiarrhythmic drug effects. Postinfarction trials, recent congestive heart failure studies, and observations in patients who are at risk for sustained ventricular arrhythmias all suggest a potent antiarrhythmic effect of beta blockade.
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Affiliation(s)
- M J Reiter
- University of Colorado Health Sciences Center, Denver 80262, USA
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44
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Reiffel JA, Reiter MJ, Blitzer M. Antiarrhythmic drugs and devices for the management of ventricular tachyarrhythmia in ischemic heart disease. Am J Cardiol 1998; 82:31I-40I. [PMID: 9737652 DOI: 10.1016/s0002-9149(98)00470-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Ischemic heart disease is the most frequent cardiac abnormality in patients with sustained or nonsustained ventricular tachyarrhythmias. The goals of therapy in such patients are to decrease the severity and incidence of symptoms and prolong life. In this article, we review the current views on antiarrhythmic drug therapy and an implantable cardioverter-defibrillator (ICD) in patients with ischemic heart disease. The importance of beta blockade as part of the therapy is emphasized. In addition, the superiority of sotalol and amiodarone over class I drugs, the benefits of combined treatment with amiodarone and a beta blocker, and the impact and limitations of current trials comparing the effectiveness of drug therapy with that of an ICD are all considered. Also discussed is the combined use of an antiarrhythmic drug and an ICD. In this approach sotalol is generally the agent of choice, with amiodarone the second choice.
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Affiliation(s)
- J A Reiffel
- Department of Medicine, Columbia University College of Physicians & Surgeons, New York, New York, USA
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45
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Abstract
Sudden cardiac death (SCD) remains a significant medical problem in the United States. The incidence of SCD increases with advancing age because cardiovascular disease is more prevalent in the elderly. Management of ventricular arrhythmias in the elderly patient is especially challenging because of increased risk of interventional and pharmacologic therapies, altered pharmacokinetics of drugs, and sometimes unclear long-term benefits.
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Affiliation(s)
- D D Tresch
- Division of Cardiology, Medical College of Wisconsin, Milwaukee, USA
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46
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Jafri SM, Borzak S, Goldberger J, Gheorghiade M. Role of antiarrhythmic agents after myocardial infarction with special reference to the EMIAT and CAMIAT trials of amiodarone. European Myocardial Infarct Amiodarone Trial. Canadian Amiodarone Myocardial Infarction Trial. Prog Cardiovasc Dis 1998; 41:65-70. [PMID: 9717860 DOI: 10.1016/s0033-0620(98)80023-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The role of antiarrhythmic agents in the post-MI patients has been investigated for several years. Recently, clinical trials have assessed the effects of amiodarone in the post-MI population. The Basel Antiarrhythmic Study of Infarct Survival (BASIS) trial showed a reduction in total mortality, sudden death, and life-threatening ventricular arrhythmias with amiodarone therapy. The European Myocardial Infarct Amiodarone Trial (EMIAT) did not show a mortality benefit, but amiodarone was associated with fewer antiarrhythmic deaths. The Canadian Amiodarone Myocardial Infarction Trial (CAMIAT) showed no significant impact on mortality, but arrhythmia deaths and resuscitated cardiac deaths were reduced. Amiodarone therapy after MI should be reserved for the treatment of symptomatic or sustained ventricular arrhythmias. The current data do not support routine use of amiodarone in all patients after MI.
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Affiliation(s)
- S M Jafri
- Henry Ford Hospital, Detroit, MI 48202, USA
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47
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Abstract
This article examines the efficacy of studying antiarrhythmic and antifibrillatory interventions using animal models. The importance of identifying appropriate animal models and comparing results from these studies to human clinical trials is discussed. Specific studies will be cited, the advantages/disadvantages of each design (i.e., internal control analysis factors, reproducibility of results, anesthetized vs conscious models) will be presented, and their ability or inability to predict clinical outcomes will be discussed.
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Affiliation(s)
- P J Schwartz
- Department of Cardiology, Policlinico S. Matteo IRCCS, and University of Pavia, Italy
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48
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Abstract
Sudden cardiac death due to arrhythmic events is the major cause of mortality among early post-myocardial infarction (MI) patients, accounting for > 250,000 deaths annually in the United States alone. Antiarrhythmic drugs can be used in such patients as well as in those who have not had a recent MI but are at high risk for sudden cardiac death (e.g., those with ventricular tachycardia/fibrillation, or who have survived cardiac arrest). Most antiarrhythmic drugs available, however, have limitations arising from their toxic and proarrhythmic potential. Thus, research and development of new agents and treatment modalities are desirable. This article seeks to enumerate the lessons of past clinical trials with these agents and to provide guidelines for future trials. That a variety of antiarrhythmic drugs have been associated with an increased mortality has been a disturbing observation. It is therefore imperative that candidates for antiarrhythmic therapy be selected appropriately. We recommend that future clinical trials use stringent criteria for the identification of patients at "high risk" for arrhythmia or sudden cardiac death, and limit recruitment to such patients. Traditional markers, such as the increased frequency and complexity of ventricular premature beats, and low left ventricular ejection fraction, have not been successful in identifying these high-risk patients. However, decreased heart rate variability and cardiac late potentials recorded on a signal-over-aged electrocardiogram appear to be more specific markers of post-MI arrhythmia or sudden cardiac death and may, in conjunction with the traditional markers, be used to improve selection of trial populations. Since the risk of sudden cardiac death diminishes with time after MI, it is also recommended that the temporal window of treatment with antiarrhythmic agents be limited to 1 year post-MI. It is also important to define clearly the endpoints of efficacy evaluations. A short-term reduction on markers like ventricular ectopic beats, for example, does not translate into a long-term decrease in arrhythmia-related mortality. Therefore, a reduction in overall mortality is the only meaningful endpoint to define the true risk-benefit ratio. To limit exposure to the potentially adverse effects of these agents, target populations for prophylactic antiarrhythmic drugs should be limited to recent post-MI patients at high risk for sudden cardiac death due to arrhythmia. Avoiding exposure of low-risk patients to antiarrhythmic drugs is equally imperative. "Low risk" of all-cause mortality includes the group of post-MI patients with a left ventricular ejection fraction >36%. Risk must be continuously evaluated in the setting of other pharmacologic (angiotensin-converting enzyme [ACE] inhibitors, aspirin, 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors ["statins"], and others) and/or nonpharmacologic interventions (coronary artery bypass graft, angioplasty, implantable cardioverter/defibrillator). There is also a need to improve noninvasive techniques for identifying patients in the high-risk category-at present, the presence of ventricular premature beats and a left ventricular ejection fraction <36% is considered somewhat predictive of sudden cardiac death. Thus, patients with a recent MI and moderately low left ventricular ejection fraction (< or = 36% but not <20%) may be considered for antiarrhythmic therapy. A subset analysis of patients with low heart rate variability can provide valuable additional information. It is important to note that although all-cause mortality is a valid endpoint for such trials, stratification by specific cause of mortality is desirable.
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Affiliation(s)
- C M Pratt
- Coronary Intensive Care Unit, Methodist Hospital, Houston, Texas 77030, USA
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49
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Kalso E, Tramèr MR, McQuay HJ, Moore RA. Systemic local-anaesthetic-type drugs in chronic pain: a systematic review. Eur J Pain 1998; 2:3-14. [PMID: 10700296 DOI: 10.1016/s1090-3801(98)90041-6] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Basic research indicates that systemic local-anaesthetic-type drugs that block sodium channels are effective in pain due to nerve damage. These drugs were first used as analgesics in the 1950s and they are still commonly used to try to relieve neuropathic pain and incident pain caused by cancer. As they are potentially toxic, these drugs should not be used without proven effectiveness. For these reasons, a systematic review of randomized controlled trials of systemically administered local-anaesthetic-type drugs in chronic pain was performed. Main outcomes were pain relief or pain intensity difference and adverse effects. Twenty-one reports were found, and four publications were excluded. In the remaining 17 studies (450 patients), 10 used intravenous lignocaine, two used intranasal lignocaine, four used oral mexiletine and one used oral tocainide. The best documented effective dose of intravenous lignocaine was 5 mg/kg, and when infused over 30 min it was well tolerated. Intravenous lignocaine was effective in all four studies in non-cancer-related neuropathic pain. In migraine, lignocaine produced an inconsistent effect. Lignocaine was without effect in all three studies in cancer-related pain. Oral mexiletine showed some efficacy in all three studies in pain due to peripheral nerve damage, but lacked effect in the only study in central pain. Only minor dose-related adverse effects were reported in the 85 patients given mexiletine 225-750 mg. Local-anaesthetic-type drugs are effective in pain due to nerve damage, but there is little or no evidence to support their use in cancer-related pain. Copyright 1998 European Federation of Chapters of the International Association for the Study of Pain.
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Affiliation(s)
- E Kalso
- Pain Research and Nuffield Department of Anaesthetics, University of Oxford, UK
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50
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Julian DG, Camm AJ, Frangin G, Janse MJ, Munoz A, Schwartz PJ, Simon P. Randomised trial of effect of amiodarone on mortality in patients with left-ventricular dysfunction after recent myocardial infarction: EMIAT. European Myocardial Infarct Amiodarone Trial Investigators. Lancet 1997; 349:667-74. [PMID: 9078197 DOI: 10.1016/s0140-6736(96)09145-3] [Citation(s) in RCA: 806] [Impact Index Per Article: 29.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Ventricular arrhythmias are a major cause of death after myocardial infarction, especially in patients with poor left-ventricular function. Previous attempts to identify and suppress arrhythmias with various antiarrhythmic drugs failed to reduce or actually increase mortality. Amiodarone is a powerful antiarrhythmic drug with several potentially beneficial actions, and has shown benefit in several small-scale studies. We postulated that this drug might reduce mortality in patients at high risk of death after myocardial infarction because of impaired ventricular function, irrespective of whether they had ventricular arrhythmias. METHODS The European Myocardial Infarct Amiodarone Trial (EMIAT) was a randomised double-blind placebo-controlled trial to assess whether amiodarone reduced all-cause mortality (primary endpoint) and cardiac mortality and arrhythmic death (secondary endpoints) in survivors of myocardial infarction with a left-ventricular ejection fraction (LVEF) of 40% or less. Intention-to-treat and on-treatment analyses were done. FINDINGS EMIAT enrolled 1486 patients (743 in the amiodarone group, 743 in the placebo group). Median follow-up was 21 months. All-cause mortality (103 deaths in the amiodarone group, 102 in the placebo group) and cardiac mortality did not differ between the two groups. However, in the amiodarone group, there was a 35% risk reduction (95% CI 0-58, p = 0.05) in arrhythmic deaths. INTERPRETATION Our findings do not support the systematic prophylactic use of amiodarone in all patients with depressed left-ventricular function after myocardial infarction. However, the lack of proarrhythmia and the reduction in arrhythmic death support the use of amiodarone in patients for whom antiarrhythmic therapy is indicated.
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Affiliation(s)
- D G Julian
- St George's Hospital Medical School, London, UK
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