Influence of aorto-coronary saphenous vein bypass surgery on left ventricular function. Comparison before and one year after surgery in 80 patients.

To assess the haemodynamic effects of aorto-coronary saphenous vein bypass grafting, pre- and post-angiographic left ventricular end-diastolic pressure (LVEDP) and ejection fraction (EF) were measured before and in average 14 months after surgery in 80 patients. Symptomatic improvement occurred in 91% (73 of 80). In 43 patients with patent graft(s), pre-angiographic LVEDP and EF were unchanged (p always greater than 0.05), while postangiographic LVEDP was significantly reduced. Unchanged pre- and postangiographic LVEDP and EF were observed in 28 patients with double or triple grafts, with at least one graft patent and the other(s) occluded. Unchanged pre- and postangiographic LVEDP and reduced EF were observed in 9 patients with occluded single, double or triple grafts. We conclude that successful aorto-coronary saphenous vein bypass surgery in general does not improve resting left ventricular performance, but that the beneficial effect on left ventricular function can be demonstrated after a stress test such as ventriculography. A single graft to the left anterior descending artery seems to be of particular importance in this connection. On the other hand, deterioration was evident after unsuccessful surgery, particularly in patients with occlusions of 2 or 3 grafts. Digitalis therapy after operation or electrocardiographic indices of postoperative myocardial infarction apparently did not influence left ventricular performance.