Hemodynamic Studies in Sickle Cell Anemia

Hemodynamic studies in 13 unselected patients with sickle cell anemia are reported. Twelve of these patients were also studied during mild exercise. The cardiac output at rest was elevated in all and rose significantly with exercise in 9 of the 12 patients. The importance of the increased percentage extraction of oxygen by the tissues in modifying the response of the cardiac output is discussed. The similarity of the response to exercise in the majority of these chronically anemic patients compared with the normal response is described. Included in this series is one case with secondary cor pulmonale and one case of concurrent rheumatic heart disease. HE clinical mimicry of rheumatic fever and rheumatic heart disease by sickle cell anemia, and the difficulty in differ-entiating some of the manifestations of sickle cell anemia from these conditions has been noted many times in the literature. Although rheumatic heart disease has been stated to be a rare concomitant of sickle cell disease,' their occurrence together has been described.2 3 Sickle cell anemia as a cause of pulmonary vascular occlusion, pulmonary hypertension, and subsequent right ventricular hypertrophy is now well authenticated.4 It has been sug-gested that sickle cell thrombi in the coronary vasculature occasionally result in coronary insufficiency.5 In view of the varied pathologic findings and the puzzling clinical picture presented by patients with sickle cell anemia, it was felt that hemodynamic studies in a group of such patients would be of interest. Furthermore, these patients offered a unique opportunity to study the circulatory adjustments to chronic and relatively constant anemia. Although studies of the circulatory state in anemia have been reported,6 ' 7 the response of such patients to exercise has not been noted. As in other disease states affecting the cardiovascular system, knowledge of the behavior of patient