The experiments on male rats revived after a 4-min clinical death caused by acute blood loss have demonstrated considerable functional and metabolic heart damage in the early rehabilitation period. It should be noted that the leading pathogenetic factors underlying this damage are excessive activation of lipid peroxidation, and enhanced hydrolysis of membrane phospholipids accompanied by arrhythmias, increased permeability of cardiomyocyte membranes, oxidation and phosphorylation disbalance, which is associated with disorders in the energy supply of myocardial contractility function. Preinjection of a synthetic antioxidant oxypyridine-6 at a dose of 50 mg/kg reduces considerably heart damage in the early postresuscitation period.