Comparison of lidoflazine and quinidine in prophylactic treatment of arrhythmias

Abstract

The efficacy of quinidine versus lidoflazine therapy was compared in the maintenance of sinus rhythm after electrical cardioversion for atrial flutter or fibrillation in a group of 35 patients. Both quinidine and lidoflazine were relatively ineffective in maintaining sinus rhythm after cardioversion. Lidoflazine was also used to prevent supraventricular and ventricular tachycardias in a miscellaneous group of patients; one of these with paroxysmal supraventricular tachycardia developed runs of ventricular tachycardia soon after starting lidoflazine. The trial was stopped after 4 patients died while receiving lidoflazine, on the suspicion that their deaths may have been related to drug-induced arrhythmias. The arrhythmogenic potential of lidoflazine when used in patients with supraventricular arrhythmias contrasts with reports of its apparent safety in large numbers of patients with angina pectoris.