EFFICACY AND RISKS OF MORICIZINE IN INDUCIBLE SUSTAINED VENTRICULAR-TACHYCARDIA

Objective: To assess the efficacy and toxicity of moricizine in treating patients with serious ventricular arrhythmias and inducible sustained ventricular tachycardia. Design: Uncontrolled clinical trial. Setting: The intensive care and telemetry units of Northwestern Memorial Hospital, St. Francis Hospital and Medical Center, and Lenox Hill Hospital. Patients: Twenty-six patients with sustained ventricular arrhythmias or hemodynamically significant nonsustained ventricular tachycardia, most of whom failed therapy with at least one class I antiarrhythmic agent. Intervention: Patients were treated with moricizine, 400 to 1000 mg/d. Measurement: Efficacy was assessed by the results of programmed ventricular stimulation done during moricizine therapy. Main Results: Seven of the 26 patients (27%) developed life-threatening ventricular proarrhythmia during moricizine loading. Three patients had incessant sustained ventricular tachycardia, two had incessant nonsustained ventricular tachycardia, one had new sustained ventricular tachycardia, and one had new cardiac arrest. One of these patients died of intractable ventricular fibrillation. No clinical or electrophysiologic variables clearly identified those at risk for proarrhythmia. Only 3 of 26 patients (12%) became noninducible on moricizine. Conclusion: Moricizine has a low rate of efficacy and carries a considerable risk for life-threatening proarrhythmia in patients with serious ventricular arrhythmias and inducible ventricular tachycardia who have failed therapy with other class I antiarrhythmic agents.