Evaluation of amiodarone therapy in the treatment of drug-resistant cardiac arrhythmias: long term follow-up.

The clinical efficacy of amiodarone in the management of patients with complex cardiac arrhythmias refractory to therapy with two or more conventional or other investigational anti-arrhythmic agents was studied by long-term follow-up of patients who had received the drug for a period of at least three months. A total of 181 patients, classified into four groups (Group 1--supraventricular arrhythmias, n = 42; Group 2--frequent VPBs, n = 46; Group 3--nonsustained V-tach, n = 16; and Group 4--sustained V-tach, n = 77) received a daily maintenance dose of 200-800 mg of Amiodarone for a period of up to 30 months. There were a total of 26 deaths (14%). Ten of these were classified as probable arrhythmic deaths; however, all had either good or excellent response to therapy over a mean follow-up period of 14.9 months prior to death. The drug had to be permanently discontinued due to side effects only in three patients and in the majority of patients with side effects symptoms could be alleviated with adjustment of dosage, thyroid replacement therapy or transient cessation of therapy. We conclude that amiodarone is highly effective in the management of high-risk patients with complex refractory cardiac arrhythmias and that close monitoring and prompt recognition of side effects and appropriate adjustment of dosage or institution of supplemental or replacement therapy (in less than 5% of patients) will allow continuation of amiodarone. The benefit of suppression of symptomatic arrhythmias and the potential of prevention of sudden death, far outweighs the incidence of severe side effects.