ACTION OF DRUGS ON CARDIAC OUTPUT

Abstract

Our present knowledge concerning the action of the so-called "cardiac stimulants" is incomplete. Many clinical and experimental studies have been made of their effects on blood pressure and pulse rate. The essential function of the heart, however, is to pump blood, and before evaluating any drug as to its circulatory action, information of its effects on the cardiac output is essential. Cardiometric and other observations on decerebrate or anesthetized animals with the chest opened cannot suffice for this purpose. Harrison and Leonard¹ have shown that digitalis, which has repeatedly been demonstrated to increase the output of the isolated heart, has precisely the opposite effect on the intact animal. The rather surprising results obtained with digitalis have seemed to warrant an investigation with the newer methods of other drugs commonly used in the treatment of patients with circulatory disorders. The results of studies on caffeine are being reported in another paper.²