An estimation of the residual volume of blood in the right ventricle of normal and diseased human hearts in vivo

Abstract

A method has been described which attempts the estimation of the residual and diastolic blood volumes of the right ventricle of normal and diseased human hearts. The procedure consisted of catheterization of the right ventricle and the pulmonary artery with a double lumen catheter and the injection of Evans blue into the right ventricle. The residual volumes were then estimated from the slope of the photographically recorded dye dilution curve. Two artificial circulation models were used to test the accuracy of the method and to establish the relationship between the various factors which influence the downward slope of the dye dilution curve. The theoretical implications and the accuracy of the method were discussed. Data on the residual volume of normal right ventricles showed large scatter which was reduced when the volumes were expressed per square meter of body surface. The average right ventricular residual volume was found to be 50 c.c. per square meter. The ratio residual volume stroke volume in the normal right ventricle was 1.7. Large residual volumes were found in patients with right ventricular failure, and the ratio residual volume stroke volume was significantly elevated (average 350 c.c. and 13.6, respectively). Considerable variations in the right ventricular residual volume were present in patients with mitral stenosis, even if the data were expressed per square meter of body surface. Correlation with clinical data revealed that, in patients with mitral stenosis and large residual volumes, right heart failure was usually present. In one patient with constrictive pericarditis, the residual volume was normal, but the ratio stroke volume residual volume was increased. Larger residual volume were found in two patients suffering from adhesive pericarditis. The physiological implications of the results obtained were discussed.