The clinical course of cardiogenic shock was studied in 441 patients with myocardial infarction. The incidence of this complication was found to be dependent on the variant of myocardial infarction and was 7.4% in primary, 14.2% in repeated myocardial infarction, and 22.2% in the recurrent variant. The duration of the shock was 3 to 4 days and its course indulant. Disorders of central and peripheral hemodynamics are of principal pathogenetic importance in cardiogenic shock; these were studied by the method of dilution of T-1824 dye. Of auxiliary importance are autoantigens entering the blood from the zone of myocardial infarction 6 hours after the onset of the disease and possessing depressor, negative inotropic and cardiotoxic properties. This was established in experiments on intact and sensitized dogs. One of the components of the shock in a second attack of myocardial infarction or in recurrent infarction may be anaphylactic shock due to reaction of autoantibodies, circulating in blood after the first myocardial infarction, with the autoantigens arriving from the focus of the fresh necrosis.