Document Detail

Electrophysiology studies in patients with dilated cardiomyopathies.
MedLine Citation:
PMID:  12438831     Owner:  NLM     Status:  MEDLINE    
Dilated cardiomyopathy is a diverse group of heart diseases with variable arrhythmia substrates. The response to programmed stimulation is dependent on spontaneous arrhythmia presentation. In patients with dilated cardiomyopathy, the majority of sustained monomorphic VT is caused by a scar-related reentrant mechanism, similar to that of coronary artery disease. The arrhythmia is uniformly inducible and is often refractory to pharmacologic therapy. Sustained VT is associated with more extensive myocardial fibrosis and non-uniform anisotropy, involving both the endocardium and epicardium, compared to those without sustained reentry. The response to programmed stimulation is more variable in patients presenting with nonsustained arrhythmia, cardiac arrest or syncope. Inducibility of monomorphic VT is much lower compared to those with ischemic heart disease. Other non-reentrant mechanism, such as focal automaticity, can also be observed in patients with monomorphic VT, in the absence of myocardial scar or evidence of slow conduction. The utility of electrophysiology studies to determine prognosis and to guide therapy remains limited in this patient population. The clinical outcome does not correlate with arrhythmia inducibility, and suppression of induced arrhythmia does not predict a good prognosis. The diagnosis of sarcoidosis or Chagas' cardiomyopathy should be considered in patients with dilated cardiomyopathy of unknown etiology, particularly in those with marked regional wall motion abnormalities and inducible VT. Epicardial reentrant circuits may be more prevalent in these cardiomyopathies, especially in those with VT related to chronic Chagas' disease. Although bundle branch reentry VT is a common finding in patients with dilated cardiomyopathy, it can occur in cardiomyopathy of any type and may coexist with other myocardial reentrant VT. It often has a typical bundle branch block QRS pattern during VT and is associated with His-Purkinje conduction delay. Evidence of macroreentry involving the bundle branches can usually be demonstrated, and catheter ablation of the bundle branches provides an effective and specific treatment.
Henry H Hsia; Francis E Marchlinski
Publication Detail:
Type:  Journal Article; Review    
Journal Detail:
Title:  Cardiac electrophysiology review     Volume:  6     ISSN:  1385-2264     ISO Abbreviation:  Card Electrophysiol Rev     Publication Date:  2002 Dec 
Date Detail:
Created Date:  2002-11-19     Completed Date:  2003-05-15     Revised Date:  2005-11-16    
Medline Journal Info:
Nlm Unique ID:  9708907     Medline TA:  Card Electrophysiol Rev     Country:  United States    
Other Details:
Languages:  eng     Pagination:  472-81     Citation Subset:  IM    
Electrophysiology Service, Cardiovascular Division, University of Pennsylvania Health System, Philadelphia, Pennsylvania, USA.
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MeSH Terms
Bundle-Branch Block / complications,  diagnosis
Cardiomyopathy, Dilated / diagnosis*,  etiology*,  mortality
Electrophysiologic Techniques, Cardiac / methods*
Risk Assessment
Sensitivity and Specificity
Severity of Illness Index
Survival Analysis
Tachycardia, Ventricular / complications,  diagnosis

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

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