Vasodilator Therapy of Cardiac Failure

(First of Two Parts)* THE symptoms of cardiac failure are related to some combination of circulatory congestion (often referred to as “backward failure”) and low cardiac output (“forward failure”). In simple pump-function terms these symptoms indicate that the heart is performing on a depressed Frank-Starling curve relating stroke volume (or cardiac output or stroke work) to ventricular diastolic filling (pressure or volume) (Fig. 1). Therapy for cardiac failure has traditionally involved the administration of an inotropic drug to increase the contractile force of the heart and the administration of a diuretic to increase the renal excretion of salt and water.