Document Detail


Detection of the fingerprint of the electrophysiological abnormalities that increase vulnerability to life-threatening ventricular arrhythmias.
MedLine Citation:
PMID:  14574021     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Reduction of sudden death requires accurate identification of patients at risk for ventricular tachycardia (VT) and effective therapies. The Multicenter Unsustained Tachycardia Trial and Multicenter Automatic Defibrillator Implantation Trials demonstrate that the implantable cardioverter defibrillator impacts favorably on the incidence of VT in patients with myocardial infarction, underscoring the need to detect the electrophysiologic abnormalities required for the development of VT. Methods used for this purpose include: Holter monitoring, ejection fraction, signal-averaged ECG, heart rate variability, T-wave alternans, baroreflex sensitivity, and programmed stimulation. Performance of each method alone has demonstrated high-negative but low-positive predictive values. Recent studies confirm that their use in combination augments performance.A second approach for improving performance has been to reexamine how well each method detects the electrophysiological derangements that lead to VT. Our recent work has focused on the signal-averaged ECG. Judging from transmural maps of ventricular activation during VT and sinus rhythm obtained from patients, late potentials fail to detect completely signals from myocardium responsible for VT. To obviate this limitation we developed an approach based on inferred epicardial potentials in the frequency domain from 190-surface ECGs using individualized heart-torso models. Torso geometry and electrode positions are measured with a 3-armed digitizer. The location of cardiac structures is determined using echocardiography. The pericardial surface is approximated by a sphere that encloses the heart. Epicardial potentials are inferred using the boundary element method with zero-order Tikhonov regularization and the Composite Residual Smoothing Operator over the QRS complex. Studies are underway to determine if analysis of bioelectrical signals enveloping arrhythmogenic tissue improves identification of patients vulnerable to VT.
Authors:
Michael E Cain; R Martin Arthur; Jason W Trobaugh
Publication Detail:
Type:  Journal Article; Review    
Journal Detail:
Title:  Journal of interventional cardiac electrophysiology : an international journal of arrhythmias and pacing     Volume:  9     ISSN:  1383-875X     ISO Abbreviation:  J Interv Card Electrophysiol     Publication Date:  2003 Oct 
Date Detail:
Created Date:  2003-10-23     Completed Date:  2004-01-06     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  9708966     Medline TA:  J Interv Card Electrophysiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  103-18     Citation Subset:  IM    
Affiliation:
Cardiovascular Division, Department of Medicine, School of Medicine, Washington University, 660 South Euclid Avenue, St. Louis, MO 63110, USA. Mcain@im.wustl.edu
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MeSH Terms
Descriptor/Qualifier:
Arrhythmias, Cardiac / diagnosis*,  epidemiology,  physiopathology
Clinical Trials as Topic
Electrophysiologic Techniques, Cardiac*
Heart Conduction System / abnormalities,  pathology
Heart Rate / physiology
Heart Ventricles / pathology,  physiopathology
Humans
Incidence
Myocardial Ischemia / diagnosis*,  epidemiology,  physiopathology
Risk Factors
Stroke Volume / physiology

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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