Depression of Left Ventricular Function Due to Acute Myocardial Ischemia and Its Reversal after Aortocoronary Saphenous-Vein Bypass

Abstract

In six patients with the "preinfarction syndrome" due to high-grade proximal occlusion of the left (five cases) or right (one case) coronary arteries, left ventricular function was evaluated before and after aortocoronary bypass surgery. Angiographically determined left ventricular ejection fraction, which was reduced before operation in the five patients with left-coronary-artery disease, returned to normal after operation. Similarly, there was definite postoperative improvement in derived indexes of myocardial contractility. Marked left ventricular hypokinesis and akinesis, which were present before operation, also disappeared after surgery. The patient with right-coronary-artery disease, on the other hand, had a normal ejection fraction and wall motion before operation, and no appreciable change was observed after operation. These findings suggest that severely depressed left ventricular function from profound myocardial ischemia due to high-grade proximal occlusive lesions of the left coronary artery or its branches may be returned to normal by restoration of blood supply to the ischemic myocardium by aortocoronary bypass surgery.