Role of electrophysiologic testing in managing patients who have ventricular tachycardia unrelated to coronary artery disease

This study examined the usefulness of programmed electrical stimulation in managing 83 patients who had ventricular tachycardia not due to coronary artery disease. Among 39 patients with a history of sustained ventricular tachycardia, programmed stimulation induced ventricular tachycardia in 14 of 14 patients with mitral valve prolapse or primary electrical disease (arrhythmias without evidence of structural heart disease) and in 13 of 25 with cardiomyopathy (total 27 of 39, 69 percent). Programmed stimulation induced nonsustained ventricular tachycardia in 15 (34 percent) of 44 patients with a history of nonsustained tachycardia (5 of 13 with mitral valve prolapse, 6 of 19 with primary electrical disease and 4 of 12 with cardiomyopathy). Seventy-three of the 83 patients were treated with antiarrhythmic drugs and then followed up for 14.4 ± 11.4 months (mean ± standard deviation). Drug therapy was determined with serial electrophysiologic testing in 31 patients. Twenty-four of these 31 patients had a history of sustained ventricular tachycardia, and drugs prevented induction of ventricular tachycardia in 9 (none of whom manifested symptomatic events) but did not prevent it in 15 (6 of whom had symptomatic events). Among seven patients with a history of nonsustained ventricular tachycardia, drugs prevented induction of ventricular tachycardia in five (none of whom had symptomatic events) and did not prevent it in two (none of whom had symptomatic events). Forty-two patients were treated using the results of noninvasive testing. Drugs suppressed spontaneous ventricular tachycardia in 15 of 15 patients with a history of sustained tachycardia (7 of whom had symptomatic events including one sudden death), and in 26 of 27 with a history of nonsustained tachycardia (6 of whom had symptomatic events including one sudden death). Thus, in patients with ventricular tachycardia unrelated to coronary artery disease: (1) programmed electrical stimulation induced ventricular tachycardia less often than in patients whose tachycardia was due to coronary artery disease; (2) programmed stimulation induced ventricular tachycardia less often in patients with a history of nonsustained versus sustained tachycardia; and (3) suppression of inducible ventricular tachycardia appeared to predict effective drug therapy but drug therapy predicted with noninvasive testing appeared to be unreliable.