Left ventricular volume curves were measured by a noninvasive technique after equilibration of 99m TC human serum albumin in 27 patients with angiographically proven coronary heart disease. Compared with normals, patients with coronary insufficiency showed a significant reduction in the ejection fraction and of maximal emptying and filling times of the left ventricle during rest. In mildly affected patients with normal ejection fractions, maximal filling was already reduced in keeping with the well known loss of compliance of the left ventricle due to coronary disease.