The left ventricular volume and the internal surface areas of noncontractile regions were measured by cineangiocardiography at 60 frames/sec in nine patients with a chronic localized noncontractile area of the left ventricle. Arteriosclerotic heart disease was proven in eight patients by means of coronary arteriography. Left ventricular end-diastolic pressure, stroke volume, ejection fraction, mean circumferential shortening, and cardiac output were also measured before and after removal of the noncontractile area and revascularization of the myocardium.The noncontractile areas, measured at end-diastole, ranged from 12 to 40% of the internal surface area of the left ventricle. Generally, impairment of the left ventricular function depended on the size of the noncontractile areas. The end-diastolic volume was approximately 150 ml/m2when the size of noncontractile areas exceeded 20-25% of the left ventricular surface area (r = +0.72;P< 0.05). The ejection fraction decreased as the size of the noncontractile areas increased (r = −0.81;P< 0.01). Following surgery, the left ventricular function, as well as the clinical condition, improved significantly, although the cardiac performance remained in the abnormal range in most patients. The ejection fraction increased (P< 0.05), and the percent circumferential shortening also improved (P< 0.05).Removal of the noncontractile area of the left ventricle and revascularization of the myocardium improved the cardiac performance and increased the sense of well being in these patients.