[Cardiac side-effects of bencyclan].

Bencyclan (Fludilat), used therapeutically as a vasodilator drug, exerts a distinct negative inotropic and chronotropic action on myocardium, in contrast to papaverine. It prolongs the functional refractory period in the isolated heart preparation. In isolated myocardial mitochondria it decreases the velocity of oxidative phosphorylation and the rate of calcium uptake. These results indicate that heart function should be checked if bencyclan is applied at high dosage, especially if other cardio-depressive substances such as narcotics, antidepressive and antiarrhythmic agents as well as beta-adrenergic blockers are used at the same time. On the other hand, the results suggest that bencyclan should be tested for possible use in the treatment of ischaemic heart disease as well as ventricular and supraventricular tachycardia.