Hemodynamic Effects of Cardiac Glycosides on Normal Human Subjects During Rest and Exercise

Studies on Digitalis. I. Direct Effects on Peripheral Vascular Resistance

“…An increase in peripheral vascular resistance accompanied the inotropic effect resulting from the administration of acetylstrophanthidin (10). These data are consonant with the observations of Williams, Zohman and Ratner, who demonstrated an elevation of arterial pressure and systemic vascular resistance in human subjects undergoing rapid digitalization (23).…”

Studies on Digitalis. X. Effects of Ouabain on Forearm Vascular Resistance and Venous Tone in Normal Subjects and in Patients in Heart Failure *

“…Excised arterial and venous strips contract when exposed to digitalis glycosides (1)(2)(3)(4), and generalized systemic arteriolar and venous constriction has been induced by digitalis in-anesthetized open-chest dogs on cardiopulmonary bypass (5,6). In normal human subjects digitalis glycosides elevate arterial pressure and either have little effect on or diminish cardiac output, thus augmenting the calculated systemic vascular resistance (7). More direct evidence that digitalis acts upon vascular smiiooth muscle was provided by the observation that the drug elevated systemic vascular resistance in patients on total cardiopulmonary bypass, in whom the systemic perfusion rate was held constant, and in whom the cardiac effects of the drug could not influence arterial pressure directly (8).…”

Hemodynamic effects of bufalin in the anesthetized dog.

“…These changes are also seen during intravenous infusion of cardiac glycosides. In normal conscious dogs and humans, 17 -20 the increase in blood pressure during infusion of the cardiac glycosides results from an increase in total peripheral resistance; cardiac output does not increase. We have not compared the pressor effect of bufalin with that of ouabain in the anesthetized dog, but, in the anesthetized rat, bufalin raises blood pressure more than ouabain.…”