CIRCULATORY MEASUREMENTS IN PATIENTS WITH RHEUMATIC HEART DISEASE BEFORE AND AFTER THE ADMINISTRATION OF DIGITALIS 1

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Abstract
Repeated circulatory measurements were performed before and after digitalization in 4 patients with rheumatic heart disease. The patients were comfortable at rest, exhibited no clinical evidence of congestive failure, but showed marked reduction in their functional capacity on attempting any muscular activity. The vital capacity of the lungs, the average cardiac output per min. and per beat, and the mean velocity of the blood flow were well below the normal. The velocity of the blood flow from the arm to face and the circulating blood volume were normal. While the average rate of blood flow was reduced as a result of heart disease, the exchange of CO2 and O between the capillaries and tissues per unit of the circulating blood volume was increased. The capillary circulation responded with increased efficiency in compensation for the impaired cardiac function. Although all the patients showed clinical improvement as a result of the administration of digitalis, the cardiac output, the velocity of blood flow, the circulating blood volume and the vital capacity of the lungs showed no significant changes. Certain aspects of the nature of circulatory failure in rheumatic heart disease are discussed. The evidence presented in this study and previous observations reported in the literature do not support the conception that the rate of blood flow is increased in circu- latory failure due to rheumatic heart disease, nor that the beneficial effect of digitalis is manifested by its capacity to reduce the cardiac output.