Open AccessA Comparison of T‐Wave Alternans and QT Dispersion as Noninvasive Predictors of Ventricular Arrhythmias
Author(s) -
Berul Charles I.,
Michaud Gregory F.,
Lee Victor C.,
Hill Sharon Laneau,
Estes Mark,
Wang Paul J.
Publication year - 1999
Publication title -
annals of noninvasive electrocardiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.494
H-Index - 48
eISSN - 1542-474X
pISSN - 1082-720X
DOI - 10.1111/j.1542-474x.1999.tb00211.x
Subject(s) - t wave alternans , medicine , repolarization , cardiology , qt interval , ventricular tachycardia , dispersion (optics) , electrocardiography , ventricular fibrillation , u wave , sudden cardiac death , electrophysiology , physics , optics
Background: The purpose of this study was to compare the utility of T‐wave alternans and dispersion markers for predicting vulnerability to ventricular arrhythmias. Microvolt level T‐wave alternans, QT dispersion (QT d ), JT dispersion, and other dispersion indices have been postulated as noninvasive markers of vulnerability to ventricular arrhythmias. However, T‐wave alternans has not been directly compared to dispersion markers in the same patient population. Methods: Twenty‐four patients underwent electrophysiological study to investigate recent syncope, ventricular tachycardia, or ventricular fibrillation. Digitized orthogonal ECGs were obtained to investigate the presence of T‐wave alternans using spectral analysis, and standard 12‐lead ECGs were obtained for QT and JT dispersion analysis. Results: T‐wave alternans measurements showed greater sensitivity than QT or JT dispersion, but similar results as the variation coefficient of the JT interval. There was no statistically significant difference in specificity, predictive values, or clinical accuracy between T‐wave alternans and any of the dispersion markers (P = N.S.). The combination of increased QT or JT dispersion and T‐wave alternans was the most specific predictor. Conclusions: Heterogeneity of repolarization amplitude and duration may both be important noninvasive ECG markers of ventricular vulnerability. In this small group of high‐risk patients, T‐wave alternans has similar clinical accuracy as the ECG interlead repolarization dispersion markers. The predictive ability of these markers may improve with standardization of methodology or a combination of these approaches. A.N.E. 1999;4(3):274–280