SummaryOut of 430 patients who were operated for coronary heart disease, 115 underwent an ergometric exercise test, a right heart catheterisation with measurement of the Pulmonary capillary wedge pressure at rest and during exercise and a coronary angiography.We have observed a relationship between the Presence and severity of angina pectoris, elecrocardiographic ST-segmcnt depression, haemodynamic PCW-pressure rise on the one hand and the angiographic severity of the coronary disease on the other. This is particularly true for left main stem lesions.The explanation for this relationship lies in the impairment of left ventricular function caused by regional disturbances of myocardial Contractility, resulting from the coronary stenosis.