Nonsustained ventricular tachycardia in coronary artery disease: relation to inducible sustained ventricular tachycardia. MUSTT Investigators.

BACKGROUND Many physicians believe that electrocardiographic characteristics of nonsustained ventricular tachycardia correlate with the risk for sudden death in survivors of myocardial infarction. Sustained ventricular tachycardia induced by programmed electrical stimulation has also been shown to predict sudden death. OBJECTIVE To determine whether electrocardiographic characteristics of spontaneous nonsustained ventricular tachycardia can predict the inducibility of sustained ventricular tachycardia by programmed electrical stimulation in patients with coronary artery disease having abnormal ventricular function. DESIGN Observational cohort study. SETTING 70 clinical electrophysiology laboratories in the United States and Canada. PATIENTS 1480 consecutive patients with coronary artery disease, left ventricular ejection fraction of 0.40 or less, and asymptomatic nonsustained ventricular tachycardia. INTERVENTION Electrophysiologic study attempting to induce sustained monomorphic ventricular tachycardia. MEASUREMENTS Daily frequency, duration, and cycle length of spontaneous episodes of nonsustained ventricular tachycardia, measured by standard electrocardiographic recordings. RESULTS No statistically significant difference in the frequency or duration of spontaneous nonsustained ventricular tachycardia was seen between patients with and those without inducible sustained ventricular tachycardia. Rates of spontaneous tachycardia were slightly slower in patients with inducible ventricular tachycardia than in patients without inducible ventricular tachycardia (P = 0.047), but the difference was not clinically significant. CONCLUSION Electrocardiographic characteristics of spontaneous nonsustained ventricular tachycardia do not predict which patients with coronary artery disease will have inducible sustained ventricular tachycardia.