Document Detail


T wave alternans threshold late after repair of tetralogy of Fallot.
MedLine Citation:
PMID:  12139287     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
INTRODUCTION: Sustained microvolt-level T wave alternans (TWA) is a marker of increased risk for malignant ventricular arrhythmia. There is a significant risk of arrhythmia and sudden death after repair of congenital heart disease. The aim of this study was to determine the prevalence and characteristics of TWA after repair of tetralogy of Fallot (TOF). METHODS AND RESULTS: TWA was evaluated during bicycle exercise in 49 subjects who had consecutively undergone transatrial-transpulmonary repair. Median values for age, age at repair, and follow-up duration were 14.9 years (11.5-20.8), 1.6 years (0.2-4.9), and 11.6 years (9.4-17.2), respectively. All patients were in New York Heart Association functional class I and were asymptomatic. Median QRS duration was 120 msec (80-150). Sustained TWA was detected in 7 (23%) of 31 subjects with adequate tests. In these 7 subjects, median onset heart rate (HR) was 120 (98-155). Median HR threshold as a percentage of predicted maximum HR (220 - age) was 58% (48-77). Sustained TWA prevalence was not significantly different compared with normal subjects (7/31 vs 9/83; P = 0.1). Onset HR in the TOF group was significantly lower [mean (SD) of 122 (20) vs 139 (12), P < 0.05]. In the TOF group with sustained TWA, the TWA occurred in 4 of 7 at <60% predicted maximum HR versus 1 of 9 normal subjects (P < 0.05); 3 of 7 had onset HR <120 versus 0 of 9 normal subjects (P < 0.03). There was no significant difference in age, gender, transannular patch use, restrictive right ventricular physiology, QRS duration, QTc, QT/QRS dispersion, or nonsustained ventricular tachycardia in subjects with or those without sustained TWA. CONCLUSION: The onset HR for sustained TWA is significantly lower after repair of TOF. Further study is required to determine whether this represents an increased risk for arrhythmia in this patient group.
Authors:
Michael M H Cheung; Robert G Weintraub; Richard J Cohen; Tom R Karl; James L Wilkinson; Andrew M Davis
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Journal of cardiovascular electrophysiology     Volume:  13     ISSN:  1045-3873     ISO Abbreviation:  J. Cardiovasc. Electrophysiol.     Publication Date:  2002 Jul 
Date Detail:
Created Date:  2002-07-25     Completed Date:  2003-02-11     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  9010756     Medline TA:  J Cardiovasc Electrophysiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  657-61     Citation Subset:  IM; S    
Affiliation:
Department of Cardiology, Royal Children's Hospital, Melbourne, Australia.
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MeSH Terms
Descriptor/Qualifier:
Adolescent
Cohort Studies
Electrocardiography*
Female
Heart Rate / physiology
Humans
Male
Tachycardia, Ventricular / etiology
Tetralogy of Fallot / complications,  physiopathology*,  surgery*
Time Factors
Investigator
Investigator/Affiliation:
R J Cohen / MIT, Cambridge

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


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