Therapy of Sustained Ventricular Arrhythmias With Amiodarone: Prediction of Efficacy With Serial Electrophysiologic Studies.

Background: Programmed electrical stimulation early during amiodarone therapy has poor prognostic capabilities; and persistent inducibility has been associated with a favorable outcome in a majority of patients. These observations result from studies that differed significantly in methodology.Methods and Results: The authors prospectively enrolled 121 patients in a standardized amiodarone dosing protocol in which amiodarone was the only antiarrhythmic agent. Electrophysiologic testing was done after 2 and 6 weeks to determine noninducibility, predictive value, and the significance of drug-induced prolongation of tachycardia cycle length. The mean age of the patients in the study was 63.2 ± 11.5 years, and their ejection fraction was 32.8 ± 11.9%. Coronary artery disease was present in 103 (85%). At 2 weeks 17 patients (14%) were no longer inducible, whereas 101 patients (86%) remained inducible. Patients in these groups were similar in age and ejection fraction. During follow-up evaluation, recurrences (3...