Effects of disopyramide and aprindine on arrhythmias after acute myocardial infarction.

The incidence of ventricular arrhythmias after myocardial infarction was compared in a double blind study of disopyramide (33 patients), aprindine (34 patients) and placebo (31 patients). Total ventricular arrhythmias were less frequent in the aprindine group than in the disopyramide group (P less than 0.05) or than in the combined disopyramide and placebo groups (P less than 0.05). The incidence of life-threatening arrhythmias and of ventricular arrhythmias in high risk patients was also reduced by aprindine compared to disopyramide (P less than 0.001) or placebo (P less than 0.001). It is concluded that aprindine is effective in reducing ventricular arrhythmias and that further investigations on its preventive use after the onset of myocardial infarction are justified.