Cardio- and hemodynamics was investigated in 69 patients with chronic coronary insufficiency without manifestations of cardiac decompensation and with symptoms of congestive incompetence of the heart by using radiocardiography and analyzing systolic phases of the left ventricle. Furthermore, fractional composition of myocardial proteins and the ATP-ase myosin activity were studied in 31 persons, who during their life-time suffered from ischemic heart disease. In patients presenting no symptoms of cardiac insufficiency significant changes in cardio- and hemodynamics along with a reduced content of the actomyosin complex proteins and their disturbed ATP-ase activity were uncovered. These changes proved more intensive in the face of manifestations indicating cardiac decompensation. Thus, a complex investigation of cardio- and hemodynamics enabled it to disclose initial disorders in the contractile activity of the myocardium in patients with chronic coronary insufficiency, when such disturbances are associated both with deranged utilization and with defective accumulation of energy in the myocardium.