A comparison of actodigin and ouabain in cats

The effects of actodigin and ouabain at infusion rates which produce death in equivalent times were compared in anesthetized cats. Actodigin-induced ventricular tachycardia occurred sooner than that induced by ouabain. However, in animals in which the infusion of drug was stopped one minute after the onset of ventricular tachycardia, the arrhythmia terminated sooner in cats given actodigin than in those given ouabain. Actodigin produced a slower heart rate and greater prolongation of the PR interval than did ouabain suggesting a greater increase in vagal tone in the actodigin treated cats. Left ventricular pressure was not changed by either drug while peak dp/dt was increased after 30 min of the ouabain infusion but not significantly more than changes produced by actodigin. Thus, the use of actodigin may be limited by the early appearance of ventricular arrhythmias.