A randomized, double-blind, parallel group comparison of disopyramide phosphate and quinidine in patients with cardiac arrhythmias.

This report summarizes the results of a randomized, double-blind, parallel group, multicenter study which compared the antiarrhythmic activity and safety of oral disopyramide phosphate and oral quinidine sulfate. A total of 124 outpatients, whose pretreatment rates of ventricular and/or supraventricular arrhythmias were documented by ambulatory ECG recordings, were randomly assigned to receive either oral disopyramide or oral quinidine for the eight-week course of the study. Every two weeks, ten-hour ambulatory ECG recordings were obtained from each patient and blood was drawn to determine serum concentrations of assigned drug.