Chronotropic, inotropic, dromotropic and coronary vasodilator effects of bisaramil, a new class I antiarrhythmic drug, assessed using canine isolated, blood-perfused heart preparations

The cardiovascular effects of a new class I antiarrhythmic drug, bisaramil, were examined using canine isolated, blood-perfused heart preparations. Bi saramil exerted negative chronotropic, inotropic and dromotropic effects as well as coronary vasodilator action, which are qualitatively the same as t hose of classical class I drugs. The selectivity of bisaramil for the intra ventricular conduction vs the other cardiac variables was compared with tha t of disopyramide and flecainide. Bisaramil was the most selective for intr aventricular conduction, while it was the least selective for ventricular m uscle contraction. We conclude that bisaramil may become a useful antiarrhy thmic drug with less cardiac adverse effects.