Abstract

Alseroxylon, reserpine and benactyzine possess significant quinidine-like activity in prolonging the refractory period of isolated rabbit atria as well as in abolishing experimentally induced atrial fibrillation and flutter in anesthetized dogs. Meprobamate is not efficacious in the atrial arrhythmias althuough it shares the propensity of quinidine to increase atrial refractoriness. It, however, equals quinidine in the suppression of ectopic activity produced by 2-stage coronary ligation in unanesthetized dogs. In this test procedure, henactyzine and alseroxylon are stronger than quinidine while reserpine is considerably weaker.