[Hemodynamic effects of disopyramide and procainamide in open-chest animals]

Hemodynamic effects of two antiarrhythmic agents, disopyramide and procainamide, have been evaluated in anesthetized open-chest healthy pigs after random administration. At therapeutic plasma concentrations none of these agents proved to have deleterious hemodynamic effects. The most important action was observed after disopyramide infusion and consisted in significant bradycardia which confirmed the known effect on sinus node automaticity of the drug. Left ventricular dp/dt, an index of cardiac contractility, was unchanged after infusion of both drugs. On the ECG intervals, only procainamide provoked a significant prolongation of QTc. It is concluded that at therapeutic dosage disopyramide does not present deleterious hemodynamic effects in animals and proves to be a valid alternative to other traditional antiarrhythmic agents.