[Action of injected disopyramide on ventricular arrhythmias and atrioventricular conduction]

The authors have studied the bathmotropic and dromotropic effects of intravenous injection of 100 mg of disopyramide, the therapeutic dose being 1 to 2 mg/kg. Out of the 28 severe arrhythmias studied, it was the ventricular extrasystoles which benefited most from treatment (79% completely successful, while there was a lesser degree of success in treating the ventricular tachycardias (35% completely successful, 30% partially successful). The negative dromotropic effect of injected disopyramide on sub-nodal conduction was studied by an endocavitary technique in 10 patients presenting with a spontaneous onset of disordered intracardiac conduction; the effects were moderate. With the exception of 4 cases who sustained complications involving rhythm and haemodynamics, the clinical and cardiovascular tolerance of patients to the drug appeared to be satisfactory.