The effect of hemodialysis on left ventricular performance in 10 uremic patients was studied utilizing echocardiography. Left ventricular function curves constructed by a lower body negative pressure method were compared before and after dialysis. Although hemodialysis caused a decrease in the stroke volume index at rest from 55 +/- 17 to 50 +/- 20 ml/m2, the left ventricular function curve did not show any detectable shift. Thus, it is concluded that a decrease in stroke volume secondary to dialysis is attributable to the reduction in preload, rather than to changes in the contractile state of the left ventricle.