THE EFFECT OF THE DIGITALIS BODIES ON THE VELOCITY OF BLOOD FLOW THROUGH THE LUNGS AND ON OTHER ASPECTS OF THE CIRCULATION. A STUDY OF NORMAL SUBJECTS AND PATIENTS WITH CARDIOVASCULAR DISEASE 1

Abstract

Circulatory measurements were performed both on normal subjects and on patients with cardiovascular disease before and after admin-isi ration of digitalis bodies, in order to obtain evidence on the effect of digitalis on the normal and on the failing circulation. Strophanthin and tincture of digitalis were administered intravenously and by mouth respectively to 8 normal persons. Large therapeutic doses failed to change appreciably the velocity of pulmonary and peripheral venous blood flow, the vital capacities of the lungs and arterial and venous pressures in normal subjects. When strophanthin, or digitalis, was administered in large therapeutic doses to 14 patients suffering from cardiovascular disease, the velocity of the pulmonary blood flow became increased in 7, was unaltered in 4, while in 3 patients it was decreased. Although the average pulse rate in 7 patients showed a reduction of 14 beats per min., the pulmonary circulation time showed an average reduction of 6.9 seconds, which corresponds to an increase of 30% in velocity of pulmonary blood flow. Velocity of blood flow in the pulmonary circuit is decreased in patients with circulatory failure. With clinical signs of improvement due to administration of digitalis or to rest the velocity of this blood flow increased, although degree of the patient''s improvement and change in velocity may not be parallel. Patients with symptoms and signs of congestive failure, even when at rest, have had a greater tendency to show definite increase in velocity of blood flow in the pulmonary circuit following administration of digitalis than patients who were compensated at rest.