Acute effects of phlebotomy on right ventricular size and performance in polycythemic patients with chronic obstructive pulmonary disease.

To assess the acute effects of phlebotomy on right ventricular size and performance, gated equilibrium radionuclide angiography was used to evaluate 10 patients with severe chronic obstructive pulmonary disease and erythrocytosis (hematocrit greater than 55%). The mean right ventricular ejection fraction was abnormal before (0.38) but not after (0.43) phlebotomy, and the increase was highly significant (p less than 0.001). Similarly, the right ventricular end-diastolic area decreased significantly from 588 to 505 pixels (p less than 0.02). No significant changes occurred on the left side. Cardiac output was unchanged or slightly increased. Thus, assuming that afterload was unchanged, as reported by other investigators, the data herein are consistent with the hypothesis that a normalization in preload shifts the Starling curve, resulting in improved right ventricular performance with preservation of the cardiac output.