[Effect of Bunaftine on the aconitine-induced atrial arrhythmias in the dog]. / Azione della bunaftine sulle aritmie atriali da aconitina nel cane

Bunaftine has a quinidine-like vagolytic effect and does not act as a beta-blocking agent. Its effect on aconitine-induced atrial fibrillation in the dog was examined. It led to suproventricular tachycardia in all cases, but re-established the sinus rhythm in only 5/15. It is felt that this lack of success is attributable to the slowing of the frequency of the primary pacemaker on the part of the drug. Slowing down of atrioventricular and intraventricular conduction by Bunaftine was revealed by lengthening of the P-R interval and widening of the Q-RS complex. Decreased blood pressure following administration of the drug appears to be due to reduction of heart rate rather than altered myocardial inotropism or peripheral resistance.

[Effect of Bunaftine on the ventricular tachycardia due to aconitine in the dog]. / Azione della bunaftine sulla tachicardia ventricolare da aconitina nel cane

Suppression of aconitine-induced ventricular tachycardia in the dog with various doses of Bunaftine was attempted. Stable re-establishment of the sinus rhythm was achieved in only 3/15 cases, whereas in 3 tachicardia was unchanged, and in 9 fibrillation appeared, due, it is thought, to the effect of the drug on myocardial conductivity, since fibrillation was the most frequent outcome when high doses were used.