Sixty three patients were examined. The diagnosis of all was made on the base of clinical picture, electrocardiographic examinations and the results from the selective coronarography. The following indices of the oxygen consumption and gas metabolism were analysed in the paper: oxygen consumption per kilogram body weight, oxygen consumption per kilogramometer work performed, labour effectivity and restoration coefficient. The results obtained reveal that the adaptation ability of the respiratory and cardiovascular system in conditions of physical loading was disturbed in patients with chronic ischemic heart disease. At the same time, the physical capacity for work and the restoration coefficient were also disturbed. The decrease of oxygen consumption per kilogram body weight, deteriorated labour effectivity, restoration coefficient and the increased oxygen consumption per kilogramometer work performed occur in parallel with the extension of the lesions of the coronary arteries and the diminution of coronary reserve. The results from those examinations, together with the results from a series of non-invasive methods for the examination of cardio-vascular system could aid the thorough diagnostic-prognostic character of ischemic heart disease and give a tentative idea for the stage of the coronary arteries lesions prior to coronarography.