Effects of digitalis glycosides on the systemic arterial and venous system: clinical importance in the pathophysiology of congestive heart failure

Abstract

Although the digitalis glycosides have been employed widely in clinical medicine for two centuries as the principal drug in the treatment of congestive heart failure, their pharmacologic principles have become established on a firm scientific basis only within the past three decades. The observation that the digitalis-induced stimulation of the force of contraction of the normal human heart is not translated into an increase in cardiac output (7), suggests possible extracardiac vascular effects of the glycosides (5). Indeed, studies in experimental animals have shown that the glycosides exert direct systemic vasoconstriction (10) and this finding has been extended to the peripheral arterial tree of patients during cardiopulmonary bypass in the course of heart operations (1). The purpose of this report is to delineate the clinical alterations produced by digitalis on the resistance vessels (systemic arterioles) and the capacitance beds (systemic veins) of the peripheral circulation (8), and then clarify the significance of these changes relative to the pathophysiology and treatment of congestive heart failure (9).