NONSUSTAINED VENTRICULAR-TACHYCARDIA IN CORONARY-ARTERY DISEASE - RELATION TO INDUCIBLE SUSTAINED VENTRICULAR-TACHYCARDIA

Background: Many physicians believe that electrocardiographic characte ristics of nonsustained ventricular tachycardia correlate with the ris k for sudden death in survivors of myocardial infarction. Sustained ve ntricular tachycardia induced by programmed electrical stimulation has also been shown to predict sudden death. Objective: To determine whet her electrocardiographic characteristics of spontaneous nonsustained v entricular tachycardia can predict the inducibility of sustained ventr icular tachycardia by programmed electrical stimulation in patients wi th coronary artery disease having abnormal ventricular function. Desig n: Observational cohort study. Setting: 70 clinical electrophysiology laboratories in the United States and Canada. Patients: 1480 consecuti ve patients with coronary artery disease, left ventricular ejection fr action of 0.40 or less, and asymptomatic nonsustained ventricular tach ycardia. Intervention: Electrophysiologic study attempting to induce s ustained monomorphic ventricular tachycardia. Measurements: Daily freq uency, duration, and cycle length of spontaneous episodes of nonsustai ned ventricular tachycardia, measured by standard electrocardiographic recordings. Results: No statistically significant difference in the f requency or duration of spontaneous nonsustained ventricular tachycard ia was seen between patients with and those without inducible sustaine d ventricular tachycardia. Rates of spontaneous tachycardia were sligh tly slower in patients with inducible ventricular tachycardia than in patients without inducible ventricular tachycardia (P = 0.047), but th e difference was not clinically significant. Conclusion: Electrocardio graphic characteristics of spontaneous nonsustained ventricular tachyc ardia do not predict which patients with coronary artery disease will have inducible sustained ventricular tachycardia.