Enhanced detection of arrhythmia vulnerability using T wave alternans, left ventricular ejection fraction, and programmed ventricular stimulation: a prospective study in subjects with chronic ischemic heart disease.

Introduction: In previous studies, the prognostic value of T wave alternans (TWA) was similar to that of programmed ventricular stimulation (PVS). However, presently it is unclear if TWA and PVS identify the same patients or provide complementary risk stratification information. In addition, the effects of left ventricular ejection fraction (LVEF) on the prognostic value of TWA are unknown.

Exercise is superior to pacing for T wave alternans measurement in subjects with chronic coronary artery disease and left ventricular dysfunction.

Introduction: T wave alternans (TWA) is a heart rate-dependent marker of vulnerability to ventricular arrhythmias. Atrial pacing and exercise both are used as provocative stimuli to elicit TWA. However, the prognostic value of the two testing methods has not been compared.

Influence of QRS duration on the prognostic value of T wave alternans.

Introduction: T wave alternans (TWA) is a promising new noninvasive marker of arrhythmia vulnerability that quantifies beat-to-beat changes in ventricular repolarization. Secondary repolarization abnormalities are common in subjects with wide QRS complexes. However, the relationship between TWA and QRS prolongation has not been evaluated.

Effects of selective autonomic blockade on T-wave alternans in humans.

Background: T-wave alternans (TWA) is an important noninvasive measure of ventricular arrhythmia vulnerability. This study tested the hypothesis that the autonomic nervous system influences TWA measurement in high-risk subjects with coronary artery disease.

Methods And Results: T-wave alternans was measured in 60 patients with coronary artery disease, left ventricular dysfunction, and inducible sustained ventricular tachycardia during electrophysiological studies.