Nonsustained ventricular tachycardia in coronary artery disease: Relation to inducible sustained ventricular tachycardia

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 spon-taneous nonsustained ventricular tachycardia do not predict which patients with coronary artery disease will have inducible sustained ventricular tachycardia.