251 patients with coronary heart disease (CHD) and a control group of 32 normal persons were examined with the purpose of establishing the determinants of the left ventricular function and comparing these determinants with the functional significance of coronary stenosis. The subjects were divided into four groups: I--controls; II--patients with normal left ventricular function (EF more than 60%); III--patients with impaired LV function (EF less than 60%) and Group IV--patients with left ventricular aneurysm. Nine parameters were obtained by multivariate discriminant analysis, which characterize and classify the left ventricular function: the ejection fraction (EF), angina pectoris, exercise ECG, left ventricular end-diastolic pressure, mean velocity of circumferential fibre shortening, left ventricular functional index, longitudinal shortening, LV systolic pressure/systolic volume ratio, and coronary index. On the basis of these parameters, all the normal persons, 88% of Group II, 92% of Group III and 72% of Group IV were classified correctly. The study proves that there is a good correlation between the EF and the haemodynamic and angiocardiographic parameters. The complex left ventricular function index facilitates the prognosis of surgical results. Abnormalities in left ventricular function cannot be reliably assessed by the coronary index values alone.