Amiodarone treatment in patients with ventricular arrhythmias

Amiodarone has been used in the therapy of supraventricular and ventricular tachycardia, and has often been categorised as a class III rather than a class I agent. However, in patients with ventricular arrhythmias, amiodarone 800mg daily for 14 days prolonged the right ventricular effective refractory period by a mean of 18.8 msec (p less than 0.05), and HV interval by a mean of 5.2 msec (p less than 0.05), these changes being similar to those noted with drugs such as quinidine, procainamide, disopyramide and encainide. The antiarrhythmic efficacy of amiodarone was evaluated in 196 patients with recurrent sustained ventricular tachycardia, recurrent ventricular fibrillation or recurrent nonsustained ventricular tachycardia. Coronary artery disease, dilated (congestive) cardiomyopathy, or other forms of heart disease were present in most patients. After 1 month of therapy, 177 patients continued to receive amiodarone and, during the remainder of the follow-up period, 139 patients had no recurrence of spontaneous ventricular tachycardia or ventricular fibrillation. Sudden cardiac death occurred in 15 patients after a mean treatment period of 10.4 months. Overall, amiodarone was an effective form of therapy in patients with ventricular tachycardia and ventricular fibrillation.