The hemodynamic effects of alpha- and beta-adrenergic blockade

1 he availability of pharmacologic agents capable of abrogating sympathetic influences on the heart and peripheral blood vessels has prompted their use in the clinical investigation of a variety of conditions ranging from shock to angina pectoris. Recent studies in experimental shock support the view that, after alpha-adrenergic blockade with Dibenzyline, the peripheral resistance falls to a greater degree in less important vascular beds, such as muscle and skin.’ Under these conditions were the cardiac output to remain steady or to fall, flow would be diverted from essential tissues. Accordingly, if improvement in the perfusion of vital structures is to be obtained, cardiac output must rise. The specific aim of this study is to determine the influence of alphaand beta-adrenergic blockade on myocardial capability.