101
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Xue Y, Zhao R, Du SH, Zhao D, Li DR, Xu JT, Xie XL, Wang Q. Decreased mRNA levels of cardiac Cx43 and ZO1 in sudden cardiac death related to coronary atherosclerosis: a pilot study. Int J Legal Med 2016; 130:915-922. [PMID: 26972693 DOI: 10.1007/s00414-016-1353-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Accepted: 02/25/2016] [Indexed: 02/07/2023]
Abstract
Sudden cardiac death (SCD) is the most frequent cause of sudden unexplained death in forensic practice. The most common cause of SCD is coronary artery disease related to coronary atherosclerosis. Previous study suggested the possible application of connexin 43 (Cx43) and zonula occludens-1 (ZO1) immunostaining in the early diagnosis of myocardial ischemia. However, there appears to be insufficient data with regard to their mRNA levels. The present study investigated the cardiac mRNA levels of Cx43 and ZO1, using forensic autopsy materials consisting of 41 control cases without any disease or structural abnormality of the heart (group 1), 32 deaths due to acute ischemic heart disease related to coronary atherosclerosis without apparent myocardial necrosis (group 2), and 29 traumatic deaths with coronary atherosclerosis (group 3). Ten candidate reference genes were evaluated in the left ventricles of 10 forensic autopsy cases. EEF1A1, PPIA, TPT1, and RPL13A were identified as the most stable reference genes. Using these validated reference genes, mRNA levels of Cx43 and ZO1 were examined in the bilateral ventricles and atria of the heart. Relative mRNA quantification demonstrated decreased calibrated normalized relative quantity (CNRQ) values of Cx43 and ZO1 in bilateral ventricles of group 2. When using one conventional reference gene (GAPDH or ACTB) for normalization, nearly no difference was detected among the three groups. These findings indicate that ventricular gap junction remodeling may be a key contributor to rhythm disturbances. Analysis of cardiac Cx43 and ZO1 using real-time PCR is useful in diagnosis of SCD, and validation of reference genes is crucial.
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Affiliation(s)
- Ye Xue
- Department of Forensic Medicine, School of Basic Medical Science, Southern Medical University, No. 1838, Guangzhou, 510515, Guangdong Province, China
| | - Rui Zhao
- Department of Forensic Pathology, China Medical University School of Forensic Medicine, Shenyang, China
| | - Si-Hao Du
- Department of Forensic Medicine, School of Basic Medical Science, Southern Medical University, No. 1838, Guangzhou, 510515, Guangdong Province, China
| | - Dong Zhao
- Collaborative Innovation Center of Judicial Civilization, Beijing, China
- Ministry of Education, Key Laboratory of Evidence Science (China University of Political Science and Law), Beijing, China
| | - Dong-Ri Li
- Department of Forensic Medicine, School of Basic Medical Science, Southern Medical University, No. 1838, Guangzhou, 510515, Guangdong Province, China
| | - Jing-Tao Xu
- Department of Forensic Medicine, School of Basic Medical Science, Southern Medical University, No. 1838, Guangzhou, 510515, Guangdong Province, China
| | - Xiao-Li Xie
- Department of Toxicology, School of Public Health and Tropical Medicine, Southern Medical University, No. 1838, Guangzhou, 510515, Guangdong Province, China.
| | - Qi Wang
- Department of Forensic Medicine, School of Basic Medical Science, Southern Medical University, No. 1838, Guangzhou, 510515, Guangdong Province, China.
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102
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Kandzari DE, Perumal R, Bhatt DL. Frequency and Implications of Ischemia Prior to Ventricular Tachyarrhythmia in Patients Treated With a Wearable Cardioverter Defibrillator Following Myocardial Infarction. Clin Cardiol 2016; 39:399-405. [PMID: 27341494 DOI: 10.1002/clc.22544] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 03/12/2016] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Autopsy studies imply that recurrent myocardial infarction (MI) accounts for the majority of sudden death early after acute MI, rather than primary arrhythmia. However, diagnosis of recurrent MI by autopsy is challenging and excludes electrocardiographic data to adjudicate arrhythmic causes. We examined the frequency of ischemia prior to treated ventricular tachycardia/fibrillation (VT/VF) and outcomes in patients using the wearable cardioverter defibrillator (WCD) following acute MI. HYPOTHESIS Primary arrhythmia, rather than ischemia, is a frequent contributor to sudden death following MI. METHODS All patients treated for VT/VF over a 6-year period while wearing a WCD following acute MI with advanced left ventricular dysfunction (ejection fraction ≤35%) were included. Patients with ST-segment changes ≥0.1 mV before VT/VF were classified ischemic. Demographics and clinical outcomes were compared between those with ischemia-mediated vs primary arrhythmia. RESULTS Among 273 patients fulfilling study criteria, 15.4% had ischemia prior to VT/VF. Clinical and WCD use characteristics did not significantly differ between ischemic and primary VT/VF groups. Termination of VT/VF by WCD treatment approximated 96% in both groups. Survival 24 hours post-treatment was 88% and 84% (P = 0.54) for patients with and without ischemic VT/VF, respectively. Furthermore, 30-day cumulative survival for those with and without ischemic VT/VF was 77% and 70%, respectively (P = 0.57). CONCLUSIONS Ischemia is an infrequent cause of VT/VF following MI, contradicting previous study conclusions that recurrent MI is responsible for most post-MI sudden death. Etiology of VT/VF, however, did not influence defibrillation success or survival, which was high for both groups.
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Affiliation(s)
- David E Kandzari
- Interventional Cardiology Research, Piedmont Heart Institute, Atlanta, Georgia
| | - Ramu Perumal
- Medical Affairs, ZOLL Medical Corporation, Pittsburgh, Pennsylvania
| | - Deepak L Bhatt
- Heart and Vascular Center, Brigham and Women's Hospital, Boston, Massachusetts
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103
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Galluzzo A, Gallo C, Battaglia A, Frea S, Canavosio FG, Botta M, Bergerone S, Gaita F. Prolonged QT interval in ST-elevation myocardial infarction. J Cardiovasc Med (Hagerstown) 2016; 17:440-5. [DOI: 10.2459/jcm.0000000000000317] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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104
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Krummen DE, Ho G, Villongco CT, Hayase J, Schricker AA. Ventricular fibrillation: triggers, mechanisms and therapies. Future Cardiol 2016; 12:373-90. [PMID: 27120223 DOI: 10.2217/fca-2016-0001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Ventricular fibrillation (VF) is a common, life-threatening arrhythmia responsible for significant morbidity and mortality. Due to challenges in safely mapping VF, a comprehensive understanding of its mechanisms remains elusive. Recent findings have provided new insights into mechanisms that sustain early VF. Notably, the central role of electrical rotors and catheter-based ablation of VF rotor substrate have been recently reported. In this article, we will review data regarding four stages of VF: initiation, transition, maintenance and evolution. We will discuss the particular mechanisms for each stage and therapies targeting these mechanisms. We also examine inherited arrhythmia syndromes, including the mechanisms and therapies specific to each. We hope that the overview of VF outlined in this work will assist other investigators in designing future therapies to interrupt this life-threatening arrhythmia.
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Affiliation(s)
- David E Krummen
- Department of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA.,Department of Medicine, VA San Diego Healthcare System, 3350 La Jolla Village Drive, San Diego, CA 92161, USA
| | - Gordon Ho
- Department of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA.,Department of Medicine, VA San Diego Healthcare System, 3350 La Jolla Village Drive, San Diego, CA 92161, USA
| | - Christopher T Villongco
- Department of Bioengineering, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Justin Hayase
- Department of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA.,Department of Medicine, VA San Diego Healthcare System, 3350 La Jolla Village Drive, San Diego, CA 92161, USA
| | - Amir A Schricker
- Department of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA.,Department of Medicine, VA San Diego Healthcare System, 3350 La Jolla Village Drive, San Diego, CA 92161, USA
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105
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Weeks PA, Sieg A, Gass JA, Rajapreyar I. The role of pharmacotherapy in the prevention of sudden cardiac death in patients with heart failure. Heart Fail Rev 2016; 21:415-31. [DOI: 10.1007/s10741-016-9546-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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106
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Linder J, Hidayatallah N, Stolerman M, McDonald TV, Marion R, Walsh C, Dolan S. Perceptions of an implantable cardioverter-defibrillator: A qualitative study of families with a history of sudden life-threatening cardiac events and recommendations to improve care. ACTA ACUST UNITED AC 2016; 29:3-14. [PMID: 25383067 DOI: 10.23861/ejbm20132929] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVE To identify major concerns associated with implantable cardioverter-defibrillators (ICDs) and to provide recommendations to adult and pediatric physicians involved in the care of patients with ICDs. BACKGROUND Cardiac ion channelopathies are a well-recognized cause of sudden cardiac death in infants, children, adolescents, and young adults. ICDs are effective in preventing sudden death from fatal arrhythmias in patients with known cardiac channelopathies. There is a paucity of research on the effect of ICDs on quality of life in patients with cardiac channelopathy diagnoses, especially young patients. METHODS A qualitative study interviewing patients and families affected by inherited arrhythmias was conducted. Fifty participants with personal or family histories of cardiac events or sudden death were interviewed individually or in focus groups by clinical psychologists. All interviews were transcribed verbatim and then analyzed and coded based on current qualitative research theory to identify themes related to the research question. Twenty-four participants discussed ICDs in their interviews. RESULTS Participants reported concerns about ICDs, and these concerns were categorized into six themes: (1) comprehension and physician-patient communication; (2) anxiety; (3) restrictions and fallacies; (4) complications; (5) utility; and (6) alternative therapy. Participants noted communication breakdowns between providers and their colleagues, and between providers and their patients. Participants and their families experienced many different forms of anxiety, including worry about the aesthetics of the ICDs and fears of being shocked. Multiple restrictions, fallacies, and complications were also cited. CONCLUSION Interview themes were used to formulate recommendations for counseling and educating patients with ICDs.
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Affiliation(s)
| | | | | | - Thomas V McDonald
- Departments of Medicine and Molecular Pharmacology, Albert Einstein College of Medicine/Wilf Family Cardiovascular Research Institute, Bronx, NY
| | - Robert Marion
- Department of Pediatrics, Children's Hospital at Montefiore/Albert Einstein College of Medicine, Bronx, NY
| | - Christine Walsh
- Department of Pediatrics, Children's Hospital at Montefiore/Albert Einstein College of Medicine, Bronx, NY
| | - Siobhan Dolan
- Department of Obstetrics & Gynecology and Women's Health, Albert Einstein College of Medicine/Montefiore, Bronx, NY
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107
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Doz P, Sperzel J. Value of The Wearable Cardioverter Defibrillator (WCD) as a Bridging-Therapy before Implantation of a Cardioverter Defibrillator (ICD). J Atr Fibrillation 2016; 8:1247. [PMID: 27909469 DOI: 10.4022/jafib.1247] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 01/22/2016] [Accepted: 02/09/2016] [Indexed: 01/30/2023]
Abstract
Wearable cardioverter defibrillators (WCD), initially available in 2002, have recently experienced more routine use in many institutions as a means of preventing sudden cardiac death (SCD) prior to implantable cardioverter defibrillator (ICD) evaluation or implantation. WCD differ from ICD by their noninvasive nature, making them well suited for patient populations who have a chance for significant cardiac recovery (such as after an acute myocardial infarction). Despite their noninvasive nature, WCD treatment of sustained ventricular tachyarrhythmias is highly successful. An additional feature is the use of response buttons, which reduces the number of conscious shocks. Duration of use varies by condition but is typically several weeks to several months. Numerous studies have shown good compliance with WCD use and excellent efficacy. Although few prospective studies have been published, several are in progress including a randomized control trial of high risk patients after myocardial infarction. WCD use is rapidly gaining popularity for patients with recent myocardial infarction, recent-onset cardiomyopathies, and acute or subacute myocarditis. Surgical delays in implanting an indicated ICD or after ICD removal are also common. WCD removal occurs when the patient either qualifies for an ICD implantation or is determined to no longer have elevated SCD risk.
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Affiliation(s)
- Priv Doz
- Kerckhoff-Klinik GmbH, Kardiologie, Elektrophysiologie, Bad Nauheim, Germany
| | - Johannes Sperzel
- Kerckhoff-Klinik GmbH, Kardiologie, Elektrophysiologie, Bad Nauheim, Germany
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108
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Filgueiras-Rama D, Jalife J. STRUCTURAL AND FUNCTIONAL BASES OF CARDIAC FIBRILLATION. DIFFERENCES AND SIMILARITIES BETWEEN ATRIA AND VENTRICLES. JACC Clin Electrophysiol 2016; 2:1-3. [PMID: 27042693 DOI: 10.1016/j.jacep.2015.12.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Evidence accumulated over the last 25 years suggests that, whether in the atria or ventricles, fibrillation may be explained by the self-organization of the cardiac electrical activity into rapidly spinning rotors giving way to spiral waves that break intermittently and result in fibrillatory conduction. The dynamics and frequency of such rotors depend on the ion channel composition, excitability and refractory properties of the tissues involved, as well as on the thickness and respective three-dimensional fiber structure of the atrial and ventricular chambers. Therefore, improving the understanding of fibrillation has required the use of multidisciplinary research approaches, including optical mapping, patch clamping and molecular biology, and the application of concepts derived from the theory of wave propagation in excitable media. Moreover, translation of such concepts to the clinic has recently opened new opportunities to apply novel mechanistic approaches to therapy, particularly during atrial fibrillation ablation. Here we review the current understanding of the manner in which the underlying myocardial structure and function influence rotor initiation and maintenance during cardiac fibrillation. We also examine relevant underlying differences and similarities between atrial fibrillation and ventricular fibrillation and evaluate the latest clinical mapping technologies used to identify rotors in either arrhythmia. Altogether, the data being discussed have significantly improved our understanding of the cellular and structural bases of cardiac fibrillation and pointed toward potentially exciting new avenues for more efficient and effective identification and therapy of the most complex cardiac arrhythmias.
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Affiliation(s)
- David Filgueiras-Rama
- Fundación Centro Nacional de Investigaciones Cardiovasculares, Carlos III (CNIC)., Myocardial Pathophysiology Area, Madrid, Spain; Hospital Clínico San Carlos, Cardiology department, Madrid, Spain
| | - José Jalife
- Fundación Centro Nacional de Investigaciones Cardiovasculares, Carlos III (CNIC)., Myocardial Pathophysiology Area, Madrid, Spain; Center for Arrhythmia Research, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, EEUU
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109
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Kasama S, Toyama T, Kurabayashi M. Usefulness of Cardiac Sympathetic Nerve Imaging Using 123Iodine-Metaiodobenzylguanidine Scintigraphy for Predicting Sudden Cardiac Death in Patients With Heart Failure. Int Heart J 2016; 57:140-4. [DOI: 10.1536/ihj.15-508] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Shu Kasama
- Department of Medicine and Biological Science (Cardiovascular Medicine), Gunma University Graduate School of Medicine
| | - Takuji Toyama
- Department of Medicine and Biological Science (Cardiovascular Medicine), Gunma University Graduate School of Medicine
| | - Masahiko Kurabayashi
- Department of Medicine and Biological Science (Cardiovascular Medicine), Gunma University Graduate School of Medicine
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110
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Katritsis DG, Gersh BJ, Camm AJ. A Clinical Perspective on Sudden Cardiac Death. Arrhythm Electrophysiol Rev 2016; 5:177-182. [PMID: 28116082 PMCID: PMC5248660 DOI: 10.15420/aer.2016:11:2] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 10/28/2016] [Indexed: 11/04/2022] Open
Abstract
This article presents the epidemiology, aetiology and pathophysiology of sudden cardiac death. The modern management of survivors as well as of family members of victims is discussed, as are the relevant recommendations of guidelines prepared by learned societies.
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Affiliation(s)
- Demosthenes G Katritsis
- Athens Euroclinic, Greece, and Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
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111
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Clancy CE, Chen-Izu Y, Bers DM, Belardinelli L, Boyden PA, Csernoch L, Despa S, Fermini B, Hool LC, Izu L, Kass RS, Lederer WJ, Louch WE, Maack C, Matiazzi A, Qu Z, Rajamani S, Rippinger CM, Sejersted OM, O'Rourke B, Weiss JN, Varró A, Zaza A. Deranged sodium to sudden death. J Physiol 2015; 593:1331-45. [PMID: 25772289 DOI: 10.1113/jphysiol.2014.281204] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Accepted: 10/14/2014] [Indexed: 12/19/2022] Open
Abstract
In February 2014, a group of scientists convened as part of the University of California Davis Cardiovascular Symposium to bring together experimental and mathematical modelling perspectives and discuss points of consensus and controversy on the topic of sodium in the heart. This paper summarizes the topics of presentation and discussion from the symposium, with a focus on the role of aberrant sodium channels and abnormal sodium homeostasis in cardiac arrhythmias and pharmacotherapy from the subcellular scale to the whole heart. Two following papers focus on Na(+) channel structure, function and regulation, and Na(+)/Ca(2+) exchange and Na(+)/K(+) ATPase. The UC Davis Cardiovascular Symposium is a biannual event that aims to bring together leading experts in subfields of cardiovascular biomedicine to focus on topics of importance to the field. The focus on Na(+) in the 2014 symposium stemmed from the multitude of recent studies that point to the importance of maintaining Na(+) homeostasis in the heart, as disruption of homeostatic processes are increasingly identified in cardiac disease states. Understanding how disruption in cardiac Na(+)-based processes leads to derangement in multiple cardiac components at the level of the cell and to then connect these perturbations to emergent behaviour in the heart to cause disease is a critical area of research. The ubiquity of disruption of Na(+) channels and Na(+) homeostasis in cardiac disorders of excitability and mechanics emphasizes the importance of a fundamental understanding of the associated mechanisms and disease processes to ultimately reveal new targets for human therapy.
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Affiliation(s)
- Colleen E Clancy
- Department of Pharmacology, University of California, Davis, Genome Building Rm 3503, Davis, CA, 95616-8636, USA
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112
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Vakil KP, Roukoz H, Tung R, Levy WC, Anand IS, Shivkumar K, Rector TS, Vaseghi M, Tholakanahalli V. Mortality prediction using a modified Seattle Heart Failure Model may improve patient selection for ventricular tachycardia ablation. Am Heart J 2015; 170:1099-104. [PMID: 26678631 DOI: 10.1016/j.ahj.2015.09.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Accepted: 09/09/2015] [Indexed: 11/18/2022]
Abstract
BACKGROUND Catheter ablation is frequently used as a palliative option to reduce shock burden in patients with ventricular tachycardia (VT). A risk prediction tool that accurately predicts short-term survival could improve patient selection for VT ablation. OBJECTIVE The objective of the study is to assess utility of the Seattle Heart Failure Model (SHFM) to predict 6-month mortality in patients undergoing VT ablation. METHODS Data on patients who underwent VT ablation at 2 tertiary institutions were retrospectively compiled. The SHFM score at the time of ablation, including 2 added VT variables, was used to predict 6-month mortality. The predicted number of deaths was compared to the observed number to assess model calibration. Model discrimination of those who died within 6 months was assessed by both K- and C-statistics. RESULTS Mean age of the 243 patients was 63 ± 12 years; 89% were male. Mean SHFM score for the cohort was 1.3 ± 1.3. The Kaplan-Meier probability of death within 6 months was 14% (34 patients). The number of deaths estimated by the SHFM at 6 months was 31 (13%) giving a predicted to observed ratio of 0.91 (95% CI 0.64-1.30). The K-statistic for 6-month mortality predictions was 0.77 (95% CI 0.73-0.81), whereas the C-statistic was 0.84 (95% CI 0.78-0.92). Patients with an SHFM score ≥4.0 had an estimated positive predictive value of 80% (95% CI 28%-99%) for dying within 6 months of VT ablation. CONCLUSION The SHFM was well calibrated to a sample of patients who underwent VT ablation and provided good discrimination of short-term deaths. This model could be useful as a prognostic tool to improve patient selection for VT ablation.
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Affiliation(s)
- Kairav P Vakil
- Division of Cardiology, University of Minnesota, Minneapolis, MN; Division of Cardiology, Veterans Affairs Health Care System, Minneapolis, MN.
| | - Henri Roukoz
- Division of Cardiology, University of Minnesota, Minneapolis, MN
| | - Roderick Tung
- Division of Cardiology, University of California, Los Angeles, CA
| | - Wayne C Levy
- Division of Cardiology, University of Washington, Seattle, WA
| | - Inder S Anand
- Division of Cardiology, University of Minnesota, Minneapolis, MN; Division of Cardiology, Veterans Affairs Health Care System, Minneapolis, MN
| | | | - Thomas S Rector
- Center for Chronic Disease Outcomes Research, Veterans Affairs Health Care System and Department of Medicine, University of Minnesota, Minneapolis, MN
| | - Marmar Vaseghi
- Division of Cardiology, University of California, Los Angeles, CA
| | - Venkatakrishna Tholakanahalli
- Division of Cardiology, University of Minnesota, Minneapolis, MN; Division of Cardiology, Veterans Affairs Health Care System, Minneapolis, MN
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113
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Zima E. Sudden Cardiac Death and Post Cardiac Arrest Syndrome. An Overview. ACTA ACUST UNITED AC 2015; 1:167-170. [PMID: 29967826 DOI: 10.1515/jccm-2015-0031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 09/28/2015] [Indexed: 01/15/2023]
Abstract
A satisfactory neurologic outcome is the key factor for survival in patients with sudden cardiac death (SCD), however this is highly dependent on the haemodynamic status. Short term cardiopulmonary resuscitation and regained consciousness on the return of spontaneous circulation (ROSC) is indicative of a better prognosis. The evaluation and treatment of SCD triggering factors and of underlying acute and chronic diseases will facilitate prevention and lower the risk of cardiac arrest. Long term CPR and a prolonged unconscious status after ROSC, in the Intensive Care Units or Coronary Care Units, indicates the need for specific treatment and supportive therapy including efforts to prevent hyperthermia. The prognosis of these patients is unpredictable within the first seventy two hours, due to unknown responses to therapeutic management and the lack of specific prognostic factors. Patients in these circumstances require the highest level of intensive care and aetiology driven treatment without any delay, independently of their coma state. Current guidelines sugest the use of multiple procedures in arriving at a diagnosis and prognosis of these critical cases.
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Affiliation(s)
- Endre Zima
- Semmelweis University, Heart and Vascular Center, Budapest, Hungary
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114
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Esibov A, Chapman FW, Melnick SB, Sullivan JL, Walcott GP. Minor Variations in Electrode Pad Placement Impact Defibrillation Success. PREHOSP EMERG CARE 2015; 20:292-8. [PMID: 26383036 DOI: 10.3109/10903127.2015.1076095] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Defibrillation is essential for resuscitating patients with ventricular fibrillation (VF), but shocks often fail to defibrillate. We hypothesized that small variations in pad placement affect shock success, and that defibrillation waveform and shock dose could compensate for suboptimal pad placement. In 10 swine experiments, electrode pads were attached at 3 adjacent anterolateral positions, less than 3 centimeters apart. At each position, 24 episodes of VF were induced and shocked, 8 episodes for each of 3 defibrillation therapies. This resulted in 9 tested combinations of pad position and defibrillation therapy, with 80 episodes of VF for each combination. An episode consisted of 15 seconds of untreated VF, followed by a first shock and, if necessary, a repeat shock. Episodes were separated by four minutes of recovery. Both electrode pad position and therapy order were randomized by experiment. Primary outcome was defined as successful VF termination after the first shock; secondary outcome was the cumulative success of the first and second shocks. First shock efficacy varied widely across the 9 tested combinations of pad position and defibrillation therapy, ranging from 11.3% to 86.3%. When grouped by therapy, first shock efficacy varied significantly between the 3 pad positions: 38.3%, 48.3%, 36.7% (p = 0.02, ANOVA), and, when grouped by pad position, it varied significantly between therapies: 15.0%, 32.5%, 75.8% (p < 0.001, ANOVA). Cumulative 2-shock success varied significantly with therapy (p < 0.001, ANOVA) but not with pad position (p = 0.30, ANOVA). The lowest first shock success was at one position in 6 of 10 animals, at another position in 4 of 10 animals, and never at the third position. Small variations in pad placement can significantly affect defibrillation shock efficacy. However, anatomical variation between individuals and the challenging conditions of real-world resuscitations make optimal pad placement impractical. Suboptimal pad placement can be overcome with defibrillation waveform and shock dose.
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115
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Jabbari R, Risgaard B, Fosbøl EL, Scheike T, Philbert BT, Winkel BG, Albert CM, Glinge C, Ahtarovski KA, Haunsø S, Køber L, Jørgensen E, Pedersen F, Tfelt-Hansen J, Engstrøm T. Factors Associated With and Outcomes After Ventricular Fibrillation Before and During Primary Angioplasty in Patients With ST-Segment Elevation Myocardial Infarction. Am J Cardiol 2015; 116:678-85. [PMID: 26150175 DOI: 10.1016/j.amjcard.2015.05.037] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 05/28/2015] [Accepted: 05/28/2015] [Indexed: 10/23/2022]
Abstract
We aimed to assess the risk factors and outcome of ventricular fibrillation (VF) before and during primary percutaneous coronary intervention (PPCI) in patients with ST-segment elevation myocardial infarction. From 1999 to 2012, we consecutively enrolled 5,373 patients with ST-segment elevation myocardial infarction. In total, 410 of the patients had VF before and 88 had VF during PPCI. During a mean follow-up of 4.2 years, 1,196 subjects died. A logistic regression model identified younger age, anterior infarct, Killip class >I at admission, and a preprocedural Thrombolysis In Myocardial Infarction flow grade of 0 to I to be significantly associated with VF before PPCI, whereas inferior infarct, a preprocedural Thrombolysis In Myocardial Infarction flow grade of 0 to I, and Killip class >I at admission were significantly associated with VF during PPCI. All-cause mortality was evaluated using the Cox regression model. Compared with the patients without VF, those with VF before or during PPCI had a significantly increased 30-day mortality, with an adjusted hazard ratio = 3.40 (95% confidence interval 1.70 to 6.70) and 4.20 (95% confidence interval 1.30 to 13.30), respectively. Importantly, there was no tendency of 30-day mortality difference between VF before and during PPCI (p = 0.170). In patients with VF before or during PPCI who survived for at least 30 days, there was no increase in the long-term mortality. In conclusion, our data suggest that 30-day mortality is the same for patients with VF before PPCI compared with VF during PPCI, and the occurrence of VF before or during PPCI was associated with increased 30-day mortality but not with long-term mortality.
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116
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Martí-Carvajal AJ, Simancas-Racines D, Anand V, Bangdiwala S. Prophylactic lidocaine for myocardial infarction. Cochrane Database Syst Rev 2015; 2015:CD008553. [PMID: 26295202 PMCID: PMC8454263 DOI: 10.1002/14651858.cd008553.pub2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
BACKGROUND Coronary artery disease is a major public health problem affecting both developed and developing countries. Acute coronary syndromes include unstable angina and myocardial infarction with or without ST-segment elevation (electrocardiogram sector is higher than baseline). Ventricular arrhythmia after myocardial infarction is associated with high risk of mortality. The evidence is out of date, and considerable uncertainty remains about the effects of prophylactic use of lidocaine on all-cause mortality, in particular, in patients with suspected myocardial infarction. OBJECTIVES To determine the clinical effectiveness and safety of prophylactic lidocaine in preventing death among people with myocardial infarction. SEARCH METHODS We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2015, Issue 3), MEDLINE Ovid (1946 to 13 April 2015), EMBASE (1947 to 13 April 2015) and Latin American Caribbean Health Sciences Literature (LILACS) (1986 to 13 April 2015). We also searched Web of Science (1970 to 13 April 2013) and handsearched the reference lists of included papers. We applied no language restriction in the search. SELECTION CRITERIA We included randomised controlled trials assessing the effects of prophylactic lidocaine for myocardial infarction. We considered all-cause mortality, cardiac mortality and overall survival at 30 days after myocardial infarction as primary outcomes. DATA COLLECTION AND ANALYSIS We performed study selection, risk of bias assessment and data extraction in duplicate. We estimated risk ratios (RRs) for dichotomous outcomes and measured statistical heterogeneity using I(2). We used a random-effects model and conducted trial sequential analysis. MAIN RESULTS We identified 37 randomised controlled trials involving 11,948 participants. These trials compared lidocaine versus placebo or no intervention, disopyramide, mexiletine, tocainide, propafenone, amiodarone, dimethylammonium chloride, aprindine and pirmenol. Overall, trials were underpowered and had high risk of bias. Ninety-seven per cent of trials (36/37) were conducted without an a priori sample size estimation. Ten trials were sponsored by the pharmaceutical industry. Trials were conducted in 17 countries, and intravenous intervention was the most frequent route of administration.In trials involving participants with proven or non-proven acute myocardial infarction, lidocaine versus placebo or no intervention showed no significant differences regarding all-cause mortality (213/5879 (3.62%) vs 199/5848 (3.40%); RR 1.02, 95% CI 0.82 to 1.27; participants = 11727; studies = 18; I(2) = 15%); low-quality evidence), cardiac mortality (69/4184 (1.65%) vs 62/4093 (1.51%); RR 1.03, 95% CI 0.70 to 1.50; participants = 8277; studies = 12; I(2) = 12%; low-quality evidence) and prophylaxis of ventricular fibrillation (76/5128 (1.48%) vs 103/4987 (2.01%); RR 0.78, 95% CI 0.55 to 1.12; participants = 10115; studies = 16; I(2) = 18%; low-quality evidence). In terms of sinus bradycardia, lidocaine effect is imprecise compared with effects of placebo or no intervention (55/1346 (4.08%) vs 49/1203 (4.07%); RR 1.09, 95% CI 0.66 to 1.80; participants = 2549; studies = 8; I(2) = 21%; very low-quality evidence). In trials involving only participants with proven acute myocardial infarction, lidocaine versus placebo or no intervention showed no significant differences in all-cause mortality (148/2747 (5.39%) vs 135/2506 (5.39%); RR 1.01, 95% CI 0.79 to 1.30; participants = 5253; studies = 16; I(2) = 9%; low-quality evidence). No significant differences were noted between lidocaine and any other antiarrhythmic drug in terms of all-cause mortality and ventricular fibrillation. Data on overall survival 30 days after myocardial infarction were not reported. Lidocaine compared with placebo or no intervention increased risk of asystole (35/3393 (1.03%) vs 14/3443 (0.41%); RR 2.32, 95% CI 1.26 to 4.26; participants = 6826; studies = 4; I(2) = 0%; very low-quality evidence) and dizziness/drowsiness (74/1259 (5.88%) vs 16/1274 (1.26%); RR 3.85, 95% CI 2.29 to 6.47; participants = 2533; studies = 6; I(2) = 0%; low-quality evidence). Overall, safety data were poorly reported and adverse events may have been underestimated. Trial sequential analyses suggest that additional trials may not be needed for reliable conclusions to be drawn regarding these outcomes. AUTHORS' CONCLUSIONS This Cochrane review found evidence of low quality to suggest that prophylactic lidocaine has very little or no effect on mortality or ventricular fibrillation in people with acute myocardial infarction. The safety profile is unclear. This conclusion is based on randomised controlled trials with high risk of bias. However (disregarding the risk of bias), trial sequential analysis suggests that additional trials may not be needed to disprove an intervention effect of 20% relative risk reduction. Smaller risk reductions might require additional higher trials.
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The prevalence of long QT interval in post-operative intensive care unit patients. J Clin Monit Comput 2015; 30:437-43. [PMID: 26169292 DOI: 10.1007/s10877-015-9736-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 07/08/2015] [Indexed: 01/09/2023]
Abstract
The severity of patient illnesses and medication complexity in post-operative critically ill patients increase the risk for a prolonged QT interval. We determined the prevalence of prolonged QTc in surgical intensive care unit (SICU) patients. We performed a prospective cross-sectional study over a 15-month period at a major academic center. SICU pre-admission and admission EKGs, patient demographics, and laboratory values were analyzed. QTc was evaluated as both a continuous and dichotomous outcome (prolonged QTc > 440 ms). 281 patients were included in the study: 92 % (n = 257) post-operative and 8 % (n = 24) non-operative. On pre-admission EKGs, 32 % of the post-operative group and 42 % of the non-operative group had prolonged QTc (p = 0.25); on post-admission EKGs, 67 % of the post-operative group but only 33 % of the non-operative group had prolonged QTc (p < 0.01). The average change in QTc in the post-operative group was +30.7 ms, as compared to +2 ms in the non-operative group (p < 0.01). On multivariable adjustment for long QTc as a dichotomous outcome, pre-admission prolonged QTc (OR 3.93, CI 1.93-8.00) and having had an operative procedure (OR 4.04, CI 1.67-9.83) were associated with developing prolonged QTc. For QTc as a continuous outcome, intra-operative beta-blocker use was associated with a statistically-significant decrease in QTc duration. None of the patients developed a lethal arrhythmia in the ICU. Prolonged QTc is common among post-operative SICU patients (67 %), however lethal arrhythmias are uncommon. The operative experience increases the risk for long QTc.
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Yang KC, Kyle JW, Makielski JC, Dudley SC. Mechanisms of sudden cardiac death: oxidants and metabolism. Circ Res 2015; 116:1937-55. [PMID: 26044249 PMCID: PMC4458707 DOI: 10.1161/circresaha.116.304691] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2014] [Accepted: 02/09/2015] [Indexed: 02/07/2023]
Abstract
Ventricular arrhythmia is the leading cause of sudden cardiac death (SCD). Deranged cardiac metabolism and abnormal redox state during cardiac diseases foment arrhythmogenic substrates through direct or indirect modulation of cardiac ion channel/transporter function. This review presents current evidence on the mechanisms linking metabolic derangement and excessive oxidative stress to ion channel/transporter dysfunction that predisposes to ventricular arrhythmias and SCD. Because conventional antiarrhythmic agents aiming at ion channels have proven challenging to use, targeting arrhythmogenic metabolic changes and redox imbalance may provide novel therapeutics to treat or prevent life-threatening arrhythmias and SCD.
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Affiliation(s)
- Kai-Chien Yang
- From the Department of Pharmacology (K.-C.Y.) and Division of Cardiology, Department of Internal Medicine (K.-C.Y.), National Taiwan University Hospital, Taipei, Taiwan; Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin, Madison (J.W.K., J.C.M.); and Lifespan Cardiovascular Institute, the Providence VA Medical Center, and Brown University, RI (S.C.D.)
| | - John W Kyle
- From the Department of Pharmacology (K.-C.Y.) and Division of Cardiology, Department of Internal Medicine (K.-C.Y.), National Taiwan University Hospital, Taipei, Taiwan; Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin, Madison (J.W.K., J.C.M.); and Lifespan Cardiovascular Institute, the Providence VA Medical Center, and Brown University, RI (S.C.D.)
| | - Jonathan C Makielski
- From the Department of Pharmacology (K.-C.Y.) and Division of Cardiology, Department of Internal Medicine (K.-C.Y.), National Taiwan University Hospital, Taipei, Taiwan; Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin, Madison (J.W.K., J.C.M.); and Lifespan Cardiovascular Institute, the Providence VA Medical Center, and Brown University, RI (S.C.D.).
| | - Samuel C Dudley
- From the Department of Pharmacology (K.-C.Y.) and Division of Cardiology, Department of Internal Medicine (K.-C.Y.), National Taiwan University Hospital, Taipei, Taiwan; Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin, Madison (J.W.K., J.C.M.); and Lifespan Cardiovascular Institute, the Providence VA Medical Center, and Brown University, RI (S.C.D.).
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119
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Characterization of in-hospital cardiac arrest in adult patients at a tertiary hospital in Kenya. Afr J Emerg Med 2015. [DOI: 10.1016/j.afjem.2014.10.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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120
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Spectral analysis-based risk score enables early prediction of mortality and cerebral performance in patients undergoing therapeutic hypothermia for ventricular fibrillation and comatose status. Int J Cardiol 2015; 186:250-8. [PMID: 25828128 DOI: 10.1016/j.ijcard.2015.03.074] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Revised: 01/26/2015] [Accepted: 03/02/2015] [Indexed: 11/22/2022]
Abstract
BACKGROUND Early prognosis in comatose survivors after cardiac arrest due to ventricular fibrillation (VF) is unreliable, especially in patients undergoing mild hypothermia. We aimed at developing a reliable risk-score to enable early prediction of cerebral performance and survival. METHODS Sixty-one out of 239 consecutive patients undergoing mild hypothermia after cardiac arrest, with eventual return of spontaneous circulation (ROSC), and comatose status on admission fulfilled the inclusion criteria. Background clinical variables, VF time and frequency domain fundamental variables were considered. The primary and secondary outcomes were a favorable neurological performance (FNP) during hospitalization and survival to hospital discharge, respectively. The predictive model was developed in a retrospective cohort (n = 32; September 2006-September 2011, 48.5 ± 10.5 months of follow-up) and further validated in a prospective cohort (n = 29; October 2011-July 2013, 5 ± 1.8 months of follow-up). RESULTS FNP was present in 16 (50.0%) and 21 patients (72.4%) in the retrospective and prospective cohorts, respectively. Seventeen (53.1%) and 21 patients (72.4%), respectively, survived to hospital discharge. Both outcomes were significantly associated (p < 0.001). Retrospective multivariate analysis provided a prediction model (sensitivity = 0.94, specificity = 1) that included spectral dominant frequency, derived power density and peak ratios between high and low frequency bands, and the number of shocks delivered before ROSC. Validation on the prospective cohort showed sensitivity = 0.88 and specificity = 0.91. A model-derived risk-score properly predicted 93% of FNP. Testing the model on follow-up showed a c-statistic ≥ 0.89. CONCLUSIONS A spectral analysis-based model reliably correlates time-dependent VF spectral changes with acute cerebral injury in comatose survivors undergoing mild hypothermia after cardiac arrest.
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Shenthar J, Deora S, Rai M, Nanjappa Manjunath C. Prolonged T peak-end and T peak-end /QT ratio as predictors of malignant ventricular arrhythmias in the acute phase of ST-segment elevation myocardial infarction: A prospective case-control study. Heart Rhythm 2015; 12:484-489. [DOI: 10.1016/j.hrthm.2014.11.034] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Indexed: 11/16/2022]
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Sorajja D, Munger TM, Shen WK. Optimal antiarrhythmic drug therapy for electrical storm. J Biomed Res 2015; 29:20-34. [PMID: 25745472 PMCID: PMC4342432 DOI: 10.7555/jbr.29.20140147] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Accepted: 12/05/2014] [Indexed: 01/08/2023] Open
Abstract
Electrical storm, defined as 3 or more separate episodes of ventricular tachycardia or ventricular fibrillation within 24 hours, carries significant morbidity and mortality. These unstable ventricular arrhythmias have been described with a variety of conditions including ischemic heart disease, structural heart disease, and genetic conditions. While implantable cardioverter defibrillator implantation and ablation may be indicated and required, antiarrhythmic medication remains an important adjunctive therapy for these persons.
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Affiliation(s)
- Dan Sorajja
- Division of Cardiovascular Diseases, Mayo Clinic Arizona, Phoenix, AZ 85054, USA
| | - Thomas M Munger
- Division of Cardiovascular Diseases, Mayo Clinic Arizona, Phoenix, AZ 85054, USA
| | - Win-Kuang Shen
- Division of Cardiovascular Diseases, Mayo Clinic Arizona, Phoenix, AZ 85054, USA
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Nicolás-Franco S, Rodríguez-González FJ, Nicolás-Boluda A, Sánchez-Martos A. Importance of ventricular function in the election of electro heart mode. Med Intensiva 2015; 39:172-8. [PMID: 25555308 DOI: 10.1016/j.medin.2014.09.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Revised: 09/17/2014] [Accepted: 09/18/2014] [Indexed: 11/29/2022]
Abstract
The integration of the ventricular function is essential when making decisions over a patient subjected to cardiac electrostimulation in order to understand the structure followed in the new cardiac stimulation and resynchronising therapy guides. To support the importance of ventricular function in cardiac electrostimulation it is important to know: (i)the deleterious effect of stimulation on the right ventricle apex; (ii)the effect over the left ventricular function produced by complete blockage of the left branch, and (iii)left ventricular disfunction as arrythmogenic substrate. When it comes to decide what type of cardiac electrostimualtion to apply we will know: the percentage of ventricular stimulation needed and its ventricular function. A normal ventricular function will enable electrostimulation from the right ventricle apex or alternative site. On the contrary, if this value is lower than 50% the most recommended electrostimulation is cardiac resynchronisation (CRT-P), which will be accompanied by defibrillation (CRT-D) if FEVI is lower than 35%.
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Affiliation(s)
- S Nicolás-Franco
- Unidad de Electroestimulación Cardíaca, Hospital General Universitario Rafael Méndez, Lorca, Murcia, España.
| | - F J Rodríguez-González
- Unidad de Electroestimulación Cardíaca, Hospital General Universitario Rafael Méndez, Lorca, Murcia, España
| | - A Nicolás-Boluda
- Biotecnología, Universidad Politécnica de Valencia, Valencia, España
| | - A Sánchez-Martos
- Unidad de Electroestimulación Cardíaca, Hospital General Universitario Rafael Méndez, Lorca, Murcia, España
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Safavi-Naeini P, Rasekh A, Razavi M, Saeed M, Massumi A. Sudden Cardiac Death in Coronary Artery Disease. Coron Artery Dis 2015. [DOI: 10.1007/978-1-4471-2828-1_24] [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: 11/28/2022]
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125
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Prevalence and prognostic significance of long QT interval in patients with acute coronary syndrome: review of the literature. J Cardiovasc Nurs 2014; 29:271-9. [PMID: 23839573 DOI: 10.1097/jcn.0b013e31829bcf1a] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
BACKGROUND Sympathetic hyperactivity is linked with several adverse cardiovascular events in patients with acute coronary syndrome (ACS). Sympathetic activity increases early in the process of ischemia through 2 mechanisms. One originates from the central nervous system and leads to enhanced sympathetic activity. The other mechanism originates at the infarct zone and leads to B receptor up-regulation and catecholamine supersensitivity. Nevertheless, sympathetic hyperactivity accompanied by an underlying myocardial structural damage is likely to increase the ventricular repolarization duration measured as QT interval on the body surface electrocardiogram. PURPOSE The aims of the current review of the literature were to examine the physiological processes underlying the use of long QT interval as a risk prediction tool in patients with ACS and to critically review and critique the existing evidence related to this matter. CONCLUSION The available evidence is contradictory and includes serious limitations in design and QT measurement and correction. Until accurate and reliable data are available, it is difficult to determine the additional clinical value and prognostic significance of long QT interval in patients with ACS beyond that in other patients. CLINICAL IMPLICATIONS Long QT interval is not uncommon among patients with ACS. Automated continuous QT interval monitoring is superior to manual QT interval measurement with the standard 10-second electrocardiogram. Optimum care for patients with ACS requires nurses to keep monitoring the QT interval several days after the initial event.
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Sara JD, Eleid MF, Gulati R, Holmes DR. Sudden cardiac death from the perspective of coronary artery disease. Mayo Clin Proc 2014; 89:1685-98. [PMID: 25440727 DOI: 10.1016/j.mayocp.2014.08.022] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Revised: 08/22/2014] [Accepted: 08/22/2014] [Indexed: 12/11/2022]
Abstract
Sudden cardiac death accounts for approximately 50% of all deaths attributed to cardiovascular disease in the United States. It is most commonly associated with coronary artery disease and can be its initial manifestation or may occur in the period after an acute myocardial infarction. Decreasing the rate of sudden cardiac death requires the identification and treatment of at-risk patients through evidence-based pharmacotherapy and interventional strategies aimed at primary and secondary prevention. For this review, we searched PubMed for potentially relevant articles published from January 1, 1970, through March 1, 2014, using the following key search terms: sudden cardiac death, ischemic heart disease, coronary artery disease, myocardial infarction, and cardiac arrest. Searches were enhanced by scanning bibliographies of identified articles, and those deemed relevant were selected for full-text review. This review outlines various mechanisms for sudden cardiac death in the setting of coronary artery disease, describes risk factors for sudden cardiac death, explores the management of cardiac arrest, and outlines optimal practice for the monitoring and treatment of patients after an acute ST-segment elevation myocardial infarction to decrease the risk of sudden death.
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Affiliation(s)
| | - Mackram F Eleid
- Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN
| | - Rajiv Gulati
- Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN
| | - David R Holmes
- Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN.
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GOUDA SHERIF, ABDELWAHAB AMIR, SALEM MOHAMED, HAMID MAGDYABDEL. Scar Characteristics for Prediction of Ventricular Arrhythmia in Ischemic Cardiomyopathy. PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2014; 38:311-8. [DOI: 10.1111/pace.12536] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Revised: 09/09/2014] [Accepted: 10/19/2014] [Indexed: 01/27/2023]
Affiliation(s)
- SHERIF GOUDA
- Department of Cardiovascular Medicine; Cairo University; Cairo Egypt
| | - AMIR ABDELWAHAB
- Department of Cardiovascular Medicine; Cairo University; Cairo Egypt
| | - MOHAMED SALEM
- Department of Radio-Diagnosis; Cairo University; Cairo Egypt
| | - MAGDY ABDEL HAMID
- Department of Cardiovascular Medicine; Cairo University; Cairo Egypt
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128
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Pun PH. The interplay between CKD, sudden cardiac death, and ventricular arrhythmias. Adv Chronic Kidney Dis 2014; 21:480-8. [PMID: 25443573 DOI: 10.1053/j.ackd.2014.06.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Revised: 06/04/2014] [Accepted: 06/27/2014] [Indexed: 12/23/2022]
Abstract
CKD patients face an increased risk of cardiovascular disease mortality, and the risk of sudden cardiac death (SCD) increases as kidney function declines. Risk factors for SCD are poorly understood and understudied among CKD patients. In the general population, coronary heart disease-associated risk factors are the most important determinants of SCD risk, but among CKD patients, there is evidence that these factors play a much smaller role. Complex relationships between CKD-specific risk factors, structural heart disease, and arrhythmic triggers contribute to the high risk of SCD and ventricular arrhythmias and modulate the effectiveness of available therapies. This review examines recent data on the epidemiology, pathophysiology, and mechanisms of SCD among CKD patients and examines current evidence regarding the use of pharmacologic and device-based therapies for management of SCD risk.
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129
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Watanabe E, Tanabe T, Osaka M, Chishaki A, Takase B, Niwano S, Watanabe I, Sugi K, Katoh T, Takayanagi K, Mawatari K, Horie M, Okumura K, Inoue H, Atarashi H, Yamaguchi I, Nagasawa S, Moroe K, Kodama I, Sugimoto T, Aizawa Y. Sudden cardiac arrest recorded during Holter monitoring: Prevalence, antecedent electrical events, and outcomes. Heart Rhythm 2014; 11:1418-25. [DOI: 10.1016/j.hrthm.2014.04.036] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2014] [Indexed: 11/30/2022]
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130
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Maes F, Marchandise S, Boileau L, Le Polain de Waroux JB, Scavée C. Evaluation of a new semiautomated external defibrillator technology: a live cases video recording study. Emerg Med J 2014; 32:481-5. [DOI: 10.1136/emermed-2013-202962] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Accepted: 06/29/2014] [Indexed: 11/04/2022]
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131
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Lujan HL, DiCarlo SE. Reperfusion-induced sustained ventricular tachycardia, leading to ventricular fibrillation, in chronically instrumented, intact, conscious mice. Physiol Rep 2014; 2:2/6/e12057. [PMID: 24973331 PMCID: PMC4208649 DOI: 10.14814/phy2.12057] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Reperfusion‐induced lethal ventricular arrhythmias are observed during relief of coronary artery spasm, with unstable angina, exercise‐induced ischemia, and silent ischemia. Accordingly, significant efforts are underway to understand the mechanisms responsible for reperfusion‐induced lethal arrhythmias and mice have become increasingly important in these efforts. However, although reperfusion‐induced sustained ventricular tachycardia leading to ventricular fibrillation (VF) has been recorded in many models, reports in mice are sparse and of limited success. Importantly, none of these studies were conducted in intact, conscious mice. Accordingly, a chronically instrumented, intact, conscious murine model of reperfusion‐induced lethal arrhythmias has the potential to be of major importance for advancing the concepts and methods that drive cardiovascular therapies. Therefore, we describe, for the first time, the use of an intact, conscious, murine model of reperfusion‐induced lethal arrhythmias. Male mice (n = 9) were instrumented to record cardiac output and the electrocardiogram. In addition, a snare was placed around the left main coronary artery. Following recovery, the susceptibility to sustained ventricular tachycardia produced by 3 min of occlusion and reperfusion of the left main coronary artery was determined in conscious mice by pulling on the snare. Reperfusion culminated in sustained ventricular tachycardia, leading to VF, in all nine conscious mice. The procedures conducted in conscious C57BL/6J mice, a strain commonly used in transgenic studies, can be utilized in genetically modified models to enhance our understanding of single gene defects on reperfusion‐induced lethal ventricular arrhythmias in intact, conscious, and complex animals. We describe, for the first time, the use of an intact, conscious, murine model of reperfusion‐induced lethal arrhythmias. This model has the potential to be of major importance for advancing the concepts and methods that drive antiarrhythmic therapies.
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Affiliation(s)
- Heidi L Lujan
- Department of Physiology, Wayne State University School of Medicine, Detroit, 48201, Michigan
| | - Stephen E DiCarlo
- Department of Physiology, Wayne State University School of Medicine, Detroit, 48201, Michigan
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132
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Leacock BW. Double Simultaneous Defibrillators for Refractory Ventricular Fibrillation. J Emerg Med 2014; 46:472-4. [DOI: 10.1016/j.jemermed.2013.09.022] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2013] [Revised: 09/16/2013] [Accepted: 09/17/2013] [Indexed: 11/25/2022]
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133
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Reis MDCM, Silva NCF, de Paola AAV, Filho BL. Ventricular arrhythmias are not a short-term reproducible phenomenon--why long recording monitoring is necessary. J Electrocardiol 2014; 47:335-41. [PMID: 24631028 DOI: 10.1016/j.jelectrocard.2014.02.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Indexed: 10/25/2022]
Abstract
BACKGROUND The variability of ventricular arrhythmias (VA) among different days of the week is not well detected by one-day Holter monitoring. AIMS To evaluate whether there are differences in VA distribution pattern during long recording period. METHODS The EKG was recorded for 14 h per day during 7 days by Holter system in 34 consecutive pat ventricular couplets and non-sustained ventricular tachycardia (NSVT) recording from patients provided graphic data. We applied the Hurst method (H Coefficient) which evaluates whether a repetitive phenomenon is random or not. When the H is >0.5 and <1 means it is not random and implies a long-term memory effect. Considering the arrhythmic variability, the data were also analyzed by repetitive ANOVA comparing incidence of arrhythmias among the days. RESULTS Isolated PVCs and ventricular couplets during 98 h recording provided graphic of the occurrence. A trend of increasing and decreasing of arrhythmias was observed which looks erratic. The H coefficient, however, was significantly >0.5 for all patients. Repeated ANOVA showed statistic difference among days in 31 patients with isolated PVCs; in 26 with ventricular couplets and 19 with NSVT when analyzed per hour during week days (p < 0.05). CONCLUSION PVCs, ventricular couplets and NSVT are not a random phenomenon. Our data suggest the occurrence of ventricular arrhythmias had no similarity among the days, making unlikely that a single Holter recording for 24h may capture this phenomenon.
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134
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Israel CW. Mechanisms of sudden cardiac death. Indian Heart J 2014; 66 Suppl 1:S10-7. [PMID: 24568819 DOI: 10.1016/j.ihj.2014.01.005] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Accepted: 01/21/2014] [Indexed: 02/06/2023] Open
Abstract
Worldwide, sudden cardiac death (SCD) is a major problem. It is most frequently caused by ventricular tachyarrhythmias: Monomorphic and polymorphic ventricular tachycardia (VT), torsade de pointes (TdP), and ventricular fibrillation (VF). Beta blockade, ACE inhibition, coronary reperfusion and other treatments have reduced the incidence of VT but pulseless electrical activity (PEA) is increasingly seen, particularly in patients with advanced chronic heart disease. From existing data, bradyarrhythmia in the form of asystole (usually complete heart block without escape rhythm) causes only a minor proportion (10-15%) of SCD. In patients aged 50 years and more, coronary artery disease plays a dominant role causing more than 75% of SCD cases, either by acute ischemia and ventricular fibrillation or by chronic scar formation and reentrant VT. In younger patients, SCD may occur in patients with structurally normal hearts. A number of arrhythmogenic disorders with an increased risk of SCD have been detected and better understood recently, such as long and short QT syndrome, Brugada syndrome, catecholaminergic polymorphic ventricular tachycardia, and the early repolarization syndrome. Most importantly, ECG signs and clinical features indicating high risk for SCD have been identified. Knowledge of the exact electrophysiologic mechanisms of ventricular tachyarrhythmias at the cellular level has been improved and mechanisms such as phase 2 reentry and reflection proposed to better understand why and how SCD occurs.
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Affiliation(s)
- Carsten W Israel
- Assistant Professor, Dept. of Medicine, Div. of Cardiology, Evangelical Hospital Bielefeld, Burgsteig 13, 33617 Bielefeld, Germany.
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135
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Betensky BP, Dixit S. Sudden cardiac death in patients with nonischemic cardiomyopathy. Indian Heart J 2014; 66 Suppl 1:S35-45. [PMID: 24568827 DOI: 10.1016/j.ihj.2013.12.047] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Accepted: 12/16/2013] [Indexed: 02/08/2023] Open
Abstract
Sudden cardiac death (SCD) is an important cause of mortality worldwide. Although SCD is most often associated with coronary heart disease, the risk of SCD in patients without ischemic heart disease is well-established. Nonischemic cardiomyopathies, including idiopathic dilated cardiomyopathy, hypertrophic cardiomyopathy and arrhythmogenic right ventricular cardiomyopathy represent three unique disease entities that have been shown to be highly associated with SCD and ventricular arrhythmias. A variety of risk stratification tools have been investigated, although the optimal strategy remains unknown. Identification of the arrhythmogenic substrate and treatment of ventricular arrhythmias in these subgroups can be challenging. Herein, we aim to discuss the current understanding of the anatomic and electrophysiologic substrate underlying ventricular arrhythmias and highlight features that may be associated with a higher risk of SCD in these 3 conditions.
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Affiliation(s)
- Brian P Betensky
- Division of Cardiac Electrophysiology, Hospital of the University of Pennsylvania, Philadelphia, PA, USA
| | - Sanjay Dixit
- Division of Cardiac Electrophysiology, Hospital of the University of Pennsylvania, Philadelphia, PA, USA; Division of Cardiac Electrophysiology, Philadelphia VA Medical Center, Philadelphia, PA, USA.
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136
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Boudreaux S, Broussard L. Sudden cardiac arrest in schools: the role of the school nurse in AED program implementation. ACTA ACUST UNITED AC 2013; 35:143-52. [PMID: 23140410 DOI: 10.3109/01460862.2012.708214] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
A school nurse has many obstacles to overcome when providing emergency care for an age group ranging from four to adulthood. The 21st century school nurse faces the challenges of providing care to medically fragile children at multiple sites, with high student-nurse ratios. The implementation of an Automated External Defibrillation (AED) program can assist the school nurse and staff in providing necessary life-saving services for Sudden Cardiac Arrest (SCA) victims of all ages. The purpose of this article is to describe AED program implementation in a school setting, including the need, essential elements, benefits, and potential concerns related to this vital component of the American Heart Association five-link chain of survival.
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137
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138
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Voxel-based morphometry and histological analysis for evaluating hippocampal damage in a rat model of cardiopulmonary resuscitation. Neuroimage 2013; 77:215-21. [DOI: 10.1016/j.neuroimage.2013.03.042] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Revised: 02/16/2013] [Accepted: 03/14/2013] [Indexed: 01/21/2023] Open
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139
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Epstein AE, Abraham WT, Bianco NR, Kern KB, Mirro M, Rao SV, Rhee EK, Solomon SD, Szymkiewicz SJ. Wearable cardioverter-defibrillator use in patients perceived to be at high risk early post-myocardial infarction. J Am Coll Cardiol 2013; 62:2000-2007. [PMID: 23916930 DOI: 10.1016/j.jacc.2013.05.086] [Citation(s) in RCA: 137] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Revised: 05/06/2013] [Accepted: 05/22/2013] [Indexed: 12/22/2022]
Abstract
OBJECTIVES The aim of this study was to describe usage of the wearable cardioverter-defibrillator (WCD) during mandated waiting periods following myocardial infarction (MI) for patients perceived to be at high risk for sudden cardiac arrest (SCA). BACKGROUND Current device guidelines and insurance coverage require waiting periods of either 40 days or 3 months before implanting a cardioverter-defibrillator post-myocardial infarction (MI), depending on whether or not acute revascularization was undertaken. METHODS We assessed characteristics of and outcomes for patients who had a WCD prescribed in the first 3 months post-MI. The WCD medical order registry was searched for patients who were coded as having had a "recent MI with ejection fraction ≤35%" or given an International Classification of Diseases, Ninth Revision 410.xx diagnostic code (acute MI), and then matched to device-recorded data. RESULTS Between September 2005 and July 2011, 8,453 unique patients (age 62.7 ± 12.7 years, 73% male) matched study criteria. A total of 133 patients (1.6%) received 309 appropriate shocks. Of these patients, 91% were resuscitated from a ventricular arrhythmia. For shocked patients, the left ventricular ejection fraction (LVEF) was ≤30% in 106, 30% to 35% in 17, >36% in 8, and not reported in 2 patients. Of the 38% of patients not revascularized, 84% had a LVEF ≤30%; of the 62% of patients revascularized, 77% had a LVEF ≤30%. The median time from the index MI to WCD therapy was 16 days. Of the treated patients, 75% received treatment in the first month, and 96% within the first 3 months of use. Shock success resulting in survival was 84% in nonrevascularized and 95% in revascularized patients. CONCLUSIONS During the 40-day and 3-month waiting periods in patients post-MI, the WCD successfully treated SCA in 1.4%, and the risk was highest in the first month of WCD use. The WCD may benefit individual patients selected for high risk of SCA early post-MI.
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Affiliation(s)
- Andrew E Epstein
- Cardiovascular Division, Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
| | - William T Abraham
- Division of Cardiovascular Medicine, Department of Medicine, Ohio State University, Columbus, Ohio
| | | | - Karl B Kern
- Division of Cardiology, Department of Medicine, University of Arizona, Tucson, Arizona
| | | | - Sunil V Rao
- Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, North Carolina
| | - Edward K Rhee
- Eller Congenital Heart Center, St. Joseph's Hospital and Medical Center, Phoenix, Arizona
| | - Scott D Solomon
- Division of Cardiovascular Medicine, Department of Medicine, Harvard Medical School, Boston, Massachusetts
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140
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Billman GE. The effects of omega-3 polyunsaturated fatty acids on cardiac rhythm: a critical reassessment. Pharmacol Ther 2013; 140:53-80. [PMID: 23735203 DOI: 10.1016/j.pharmthera.2013.05.011] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Accepted: 05/17/2013] [Indexed: 11/28/2022]
Abstract
Although epidemiological studies provide strong evidence for an inverse relationship between omega-3 polyunsaturated fatty acids (n-3 PUFAs) and cardiac mortality, inconsistent and often conflicting results have been obtained from both animal studies and clinical prevention trials. Despite these heterogeneous results, some general conclusions can be drawn from these studies: 1) n-PUFAs have potent effects on ion channels and calcium regulatory proteins that vary depending on the route of administration. Circulating (acute administration) n-3 PUFAs affect ion channels directly while incorporation (long-term supplementation) of these lipids into cell membranes indirectly alter cardiac electrical activity via alteration of membrane properties. 2) n-3 PUFAs reduce baseline HR and increase HRV via alterations in intrinsic pacemaker rate rather than from changes in cardiac autonomic neural regulation. 3) n-3 PUFAs may be only effective if given before electrophysiological or structural remodeling has begun and have no efficacy against atrial fibrillation. 5) Despite initial encouraging results, more recent clinical prevention and animal studies have not only failed to reduce sudden cardiac death but actually increased mortality in angina patients and increased rather than decreased malignant arrhythmias in animal models of regional ischemia. 6) Given the inconsistent benefits reported in clinical and experimental studies and the potential adverse actions on cardiac rhythm noted during myocardial ischemia, n-3 PUFA must be prescribed with caution and generalized recommendations to increase fish intake or to take n-3 PUFA supplements need to be reconsidered.
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Affiliation(s)
- George E Billman
- Department of Physiology and Cell Biology, The Ohio State University, 304 Hamilton Hall, 1645 Neil Ave., Columbus, OH 43210-1218, United States.
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141
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Chen X, Tereshchenko LG, Berger RD, Trayanova NA. Arrhythmia risk stratification based on QT interval instability: an intracardiac electrocardiogram study. Heart Rhythm 2013; 10:875-80. [PMID: 23416373 PMCID: PMC3703156 DOI: 10.1016/j.hrthm.2013.02.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2012] [Indexed: 10/27/2022]
Abstract
BACKGROUND Experimental studies have demonstrated that unstable repolarization dynamics is a risk factor of arrhythmia. We have recently developed an algorithm to detect QT interval (QTI) instability from the clinical electrocardiogram (ECG). OBJECTIVE To develop a clinical arrhythmia risk stratification index based on the detection of QTI instability. METHODS Intracardiac ECGs were recorded at rest in 114 patients with implanted implantable cardioverter-defibrillators (ICDs). Patients were followed up until appropriate implantable cardioverter-defibrillator therapy or death occurred, whichever came first. Each ECG recording was divided into 1-minute episodes (minECGs); the instability in QTI dynamics, if any, of each minECG was detected with our algorithm. An arrhythmia risk index termed QTI instability index (QTII) was defined as the number of minECGs with unstable QTI dynamics normalized by the number of minECGs with premature activations. The performance of QTII in arrhythmia risk stratification was examined with survival analysis and was compared with other risk indices, such as the mean RR interval (RRI), the standard deviation of the RRI and the QTI, and the frequency of premature activation. We hypothesized that the index QTII, which accounts for multiple risk factors and their interdependence, performs better than indices quantifying individual arrhythmia risk factors in the stratification of arrhythmia risk. RESULTS The results of survival analysis show that QTII outperformed all other studied indices in arrhythmia risk stratification and was the only independent indicator of arrhythmia propensity in a multivariate survival model. CONCLUSION QTII is a promising arrhythmia risk stratification index.
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Affiliation(s)
- Xiaozhong Chen
- Institute for Computational Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Larisa G Tereshchenko
- Division of Cardiology, Department of Medicine, The Johns Hopkins Medical Institutions, Baltimore, Maryland, USA
| | - Ronald D. Berger
- Division of Cardiology, Department of Medicine, The Johns Hopkins Medical Institutions, Baltimore, Maryland, USA
| | - Natalia A. Trayanova
- Institute for Computational Medicine, Johns Hopkins University, Baltimore, Maryland, USA
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142
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Abstract
BACKGROUND In postmyocardial infarction patients, transient episodes of ischemia are associated with a greater incidence of sudden cardiac death (SCD). Ventricular tachycardia and ventricular fibrillation (VF) are responsible for the majority of SCDs, but current pharmacological interventions for prevention of lethal ventricular arrhythmias are less than satisfactory. We investigated the efficacy of HBI-3000 (HBI), a novel antiarrhythmic agent, in preventing SCD in a conscious canine model. METHODS After 3 to 7 days of a surgically induced myocardial infarction (ie, 90-minute occlusion of the left anterior descending coronary artery followed by 30 minutes of reperfusion), conscious animals were administered vehicle (0.9% NaCl solution for injection) or HBI (15 mg/kg) intravenously. An occlusive thrombus at a site remote from the previous myocardial infarction was induced by electrolytic injury to the intimal surface of the left circumflex coronary artery. RESULTS Control animals developed premature ventricular complexes (PVCs) followed by ventricular tachycardia, which terminated in VF in 5 of the 8 dogs. HBI reduced the frequency of PVCs, and only 1 of the 9 HBI-treated animals developed VF (P < .05). In a separate group of postinfarcted animals, the electrical conversion threshold was assessed before and after the intravenous administration of HBI (5, 10, or 15 mg/kg) or flecainide (3 mg/kg), a class IC antiarrhythmic agent. The electrical conversion threshold was not altered by HBI, whereas the administration of flecainide increased the threshold (P < .01 vs baseline). CONCLUSIONS The data indicate that HBI is an effective antiarrhythmic and antifibrillatory agent for the prevention of VF or sudden cardiac death.
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Affiliation(s)
- Jullia Y Lee
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI 48109-5632, USA.
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143
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Pizzuto MF, Suzuki G, Banas MD, Heavey B, Fallavollita JA, Canty JM. Dissociation of hemodynamic and electrocardiographic indexes of myocardial ischemia in pigs with hibernating myocardium and sudden cardiac death. Am J Physiol Heart Circ Physiol 2013; 304:H1697-707. [PMID: 23585137 DOI: 10.1152/ajpheart.00166.2013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Many survivors of sudden cardiac death (SCD) have normal global ventricular function and severe coronary artery disease but no evidence of symptomatic ischemia or infarction before the development of lethal ventricular arrhythmias, and the trigger for ventricular tachycardia (VT)/ventricular fibrillation (VF) remains unclear. We sought to identify the role of spontaneous ischemia and temporal hemodynamic factors preceding SCD using continuous telemetry of left ventricular (LV) pressure and the ECG for periods up to 5 mo in swine (n = 37) with hibernating myocardium who experience spontaneous VT/VF in the absence of heart failure or infarction. Hemodynamics and ST deviation at the time of VT/VF were compared with survivors with hibernating myocardium as well as sham controls. All episodes of VT/VF occurred during sympathetic activation and were initiated by single premature ventricular contractions, and the VT degenerated into VF in ∼ 30 s. ECG evidence of ischemia was infrequent and no different from those that survived. Baseline hemodynamics were no different among groups, but LV end-diastolic pressure during sympathetic activation was higher at the time of SCD (37 ± 4 vs. 26 ± 4 mmHg, P < 0.05) and the ECG demonstrated QT shortening (155 ± 4 vs. 173 ± 5 ms, P < 0.05). The week before SCD, both parameters were no different from survivors. These data indicate that there are no differences in the degree of sympathetic activation or hemodynamic stress when VT/VF develops in swine with hibernating myocardium. The transiently elevated LV end-diastolic pressure and QT shortening preceding VT/VF raises the possibility that electrocardiographically silent subendocardial ischemia and/or mechanoelectrical feedback serve as a trigger for the development of SCD in chronic ischemic heart disease.
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Affiliation(s)
- Matthew F Pizzuto
- Veterans Affairs Western New York Health Care System, Buffalo, NY, USA
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144
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L'italien AJ. Critical cardiovascular skills and procedures in the emergency department. Emerg Med Clin North Am 2013. [PMID: 23200332 DOI: 10.1016/j.emc.2012.09.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The management of cardiovascular emergencies is a fundamental component of the practice of an emergency practitioner. Delays in the evaluations and management can lead to significant morbidity or mortality. It is of vital importance to be familiar with procedures such as pericardiocentesis, cardioversion, defibrillation, temporary pacing, and options for the management of tachyarrhythmias. This article discusses the most common cardiovascular procedures encountered in an emergency setting, including the indications, contraindications, equipment, technique, and complications for each procedure.
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Affiliation(s)
- Anita J L'italien
- Department of Emergency Medicine, Wake Emergency Physicians, PA, 3000 New Bern Avenue, Medical Office Building, Raleigh, NC 27610, USA. l'
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145
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Mirza M, Strunets A, Shen WK, Jahangir A. Mechanisms of arrhythmias and conduction disorders in older adults. Clin Geriatr Med 2013; 28:555-73. [PMID: 23101571 DOI: 10.1016/j.cger.2012.08.005] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Aging is associated with an increased prevalence of cardiac arrhythmias, which contribute to higher morbidity and mortality in the elderly. The frequency of cardiac arrhythmias, particularly atrial fibrillation and ventricular tachyarrhythmia, is projected to increase as the population ages, greatly impacting health care resource utilization. Several clinical factors associated with the risk of arrhythmias have been identified in the population, yet the molecular bases for the increased predisposition to arrhythmogenesis in the elderly are not fully understood. This review highlights the epidemiology of cardiac dysrhythmias, changes in cardiac structure and function associated with aging, and the basis for arrhythmogenesis in the elderly.
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Affiliation(s)
- Mahek Mirza
- Center for Integrative Research on Cardiovascular Aging (CIRCA), Aurora University of Wisconsin Medical Group, Aurora Health Care, 3033 South 27th Street, Milwaukee, WI 53215, USA
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Mavrogeni S, Petrou E, Kolovou G, Theodorakis G, Iliodromitis E. Prediction of ventricular arrhythmias using cardiovascular magnetic resonance. Eur Heart J Cardiovasc Imaging 2013; 14:518-25. [PMID: 23324829 DOI: 10.1093/ehjci/jes302] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Ventricular tachycardia (VT) is the commonest cause of sudden cardiac death (SCD) in developed countries. Coronary artery disease (CAD) is the most frequent cause of VT in individuals over the age of 30, while hypertrophic cardiomyopathy (HCM), myocarditis and congenital heart disease in those below 30 years of age. Cardiac magnetic resonance (CMR), a non-invasive, non-radiating technique, can reliably detect the changes in ventricular volumes and the ejection fraction that can be predictive of VT/SCD. Furthermore, the capability of CMR to perform tissue characterization and detect oedema, fat and fibrotic substrate, using late gadolinium enhanced images (LGE), can predict VT/SCD in both ischaemic and non-ischaemic cardiomyopathy. The extent of LGE in HCM is correlated with risk factors of SCD and the likelihood of inducible VT. In idiopathic-dilated cardiomyopathy, the presence of midwall fibrosis, assessed by CMR, also predicts SCD/VT. Additionally, in arrhythmogenic right ventricle (RV) dysplasia/cardiomyopathy, CMR has an excellent correlation with histopathology and predicted inducible VT on programmed electrical stimulation, suggesting a possible role in evaluation and diagnosis of these patients. A direct correlation between LGE and VT prediction has been identified only in chronic Chagas' heart disease, but not in viral myocarditis. In CAD, infarct size is the strongest predictor of VT inducibility. The peri-infarct zone may also play a role; however, further studies are needed for definite conclusions. Left ventricle, RV, right ventricular outflow tract (RVOT) function, pulmonary regurgitation and LGE around the infundibular patch and RV anterior wall play an important role in the VT prediction in repaired Tetralogy of Fallot. Finally, in treated transposition of great arteries, the extent of LGE in the systemic RV correlates with age, ventricular dysfunction, electrophysiological parameters and adverse clinical events, suggesting prognostic importance.
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Affiliation(s)
- Sophie Mavrogeni
- Onassis Cardiac Surgery Center, 50 Esperou Street, P. Faliro, Athens 175-61 Greece.
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147
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Kleemann T, Kouraki K, Strauss M, Skarlos A, Zeymer U, Zahn R. Prognostic value of electromagnetic QRS fragmentation in survivors of sustained ventricular tachycardia or ventricular fibrillation compared with healthy controls. J Interv Card Electrophysiol 2012. [PMID: 23179924 DOI: 10.1007/s10840-012-9754-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
BACKGROUND Magnet field imaging (MFI) is a noninvasive method to determine cardiac electromagnetic activity. AIM OF THE STUDY This study aims to compare the electromagnetic QRS fragmentation index (eQFI) in survivors of sustained ventricular tachycardia (VT) or ventricular fibrillation (VF) to healthy individuals. METHODS Twenty-five consecutive patients with documented sustained VT or VF who underwent a MFI investigation between December 2009 and October 2011 were compared with 25 age- and sex-matched healthy individuals. RESULTS Patients with documented VT or VF showed a trend to higher eQFI values compared with the control group (p = 0.06). This increase was mainly driven by VT/VF patients with ischemic cardiomyopathy (CMP) which was markedly elevated compared with the healthy controls (1.48 vs. 1.07; p = 0.01). In patients with nonischemic CMP or acute coronary syndrome, eQFI was not different from the healthy group. CONCLUSIONS Electromagnetic QRS fragmentation is increased in VT/VF patients with ischemic CMP but not in patients with ventricular arrhythmias of other origin. Further investigations in prospective cohorts should evaluate the prognostic value of electromagnetic QRS fragmentation in patients with ischemic heart disease to predict the occurrence of VT/VF and to guide therapy.
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Affiliation(s)
- Thomas Kleemann
- Medizinische Klinik B, Klinikum Ludwigshafen, Bremserstraße 79, 67063, Ludwigshafen, Germany.
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Piccirillo G, Rossi P, Mitra M, Quaglione R, Dell'Armi A, Di Barba D, Maisto D, Lizio A, Barillà F, Magrì D. Indexes of temporal myocardial repolarization dispersion and sudden cardiac death in heart failure: any difference? Ann Noninvasive Electrocardiol 2012; 18:130-9. [PMID: 23530483 DOI: 10.1111/anec.12005] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND The QT variability index, calculated between Q- and the T-wave end (QTend VI), is an index of temporal myocardial repolarization lability associated with sudden cardiac death (SCD) in chronic heart failure (CHF). Little is known about temporal variability in the other two temporal myocardial repolarization descriptors obtained from Q-Tpeak and Tpeak -Tend intervals. We therefore investigated differences between these indexes in patients with CHF who died suddenly and in those who survived with a left ventricular ejection fraction (LVEF) ≤35% or >35%. METHODS AND RESULTS We selected 127 ECG and systolic blood pressure (SPB) recordings from outpatients with CHF all of whom had been followed up for 30 months. We calculated RR and SPB variability by power spectral analysis and QTend VI, QTpeak VI, Tpeak Tend VI. We then subdivided data patients into three groups SCD, LVEF ≤ 35%, and LVEF > 35%. The LVEF was higher in the SCD than in the LVEF ≤ 35% group, whereas no difference was found between the SCD and LVEF > 35% groups. QTend VI, QTpeak VI, and Tpeak Tend VI were higher in the SCD and LVEF ≤ 35% groups than in the LVEF > 35% group. Multivariate analysis detected a negative relationship between all repolarization variability indexes, low frequency obtained from RR intervals and LVEF. CONCLUSIONS Our data show that variability in the first (QTpeak VI) and second halves of the QT interval (Tpeak -Tend VI) significantly contributes to the QTend VI in patients with CHF. Further studies should investigate whether these indexes might help stratify the risk of SCD in patients with a moderately depressed LVEF.
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Affiliation(s)
- Gianfranco Piccirillo
- Department of Cardiovascular, Respiratory, Nephrologic, and Geriatric Sciences, Sapienza University of Rome, 00185 Rome, Italy.
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Scott PA, Rosengarten JA, Shahed A, Yue AM, Murday DC, Roberts PR, Peebles CR, Harden SP, Curzen NP, Morgan JM. The relationship between left ventricular scar and ventricular repolarization in patients with coronary artery disease: insights from late gadolinium enhancement magnetic resonance imaging. ACTA ACUST UNITED AC 2012; 15:899-906. [DOI: 10.1093/europace/eus362] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Nardini C, Annoni M, Schiavone G. Mechanistic understanding in clinical practice: complementing evidence-based medicine with personalized medicine. J Eval Clin Pract 2012; 18:1000-5. [PMID: 22994998 DOI: 10.1111/j.1365-2753.2012.01907.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
In the last century, medicine has undergone an unprecedented wave of radical changes. From the implementation of surgery up to the development of single gene-targeted therapies, clinical decision making has become increasingly complex to handle. Today, this complexity needs to be rethought in the light of two emerging paradigms: evidence-based medicine (EBM) and personalized medicine (P-Med). The new availability of diverse sources of scientific evidence raises significant issues concerning how clinicians will compare, evaluate and orient their decisions in front of a rapidly growing plethora of therapies, procedures, medical technologies and drugs. In this paper, we compare the background visions behind these two paradigms, evaluating their respective relevance for present and future clinical decision making. In particular, we argue that EBM and P-Med are driven by two diverse modes of reasoning about 'evidence making' in medicine. EBM is grounded on statistical notions and epidemiological data, generally gathered through systematic meta-reviews of randomized controlled trials; P-Med, instead, is grounded on mechanistic explanations of molecular interactions, metabolic pathways and biomarkers. While both paradigms are epistemically sound, we argue that they cannot, and should not, be hybridized into a unique model. Rather, they ought to represent two compatible, but alternative ways of informing the clinical practice. Hence, we conclude that clinicians may expect to see their responsibility increasing as they will deal with diverse, but equally compelling, ways of reasoning and deciding about which intervention will qualify as the 'best one' in each individual case.
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