The time course of changes in myocardial lipid peroxidation processes was studied in an experiment on albino male rats that had experienced 4-minute clinical death. There was an alternation of periods of a significant increase (minute 90, hours 3—6, and days 1—3 and 14) and a decrease (days 7, 21, and 30) in the rate of lipoprotein processes and corresponding changes in the content of lipid hydroperoxides and Schiff s bases. Activation of lipid peroxidation processes occurred with deficiency of bioantioxidants and with inhibition of enzymes that made antiradical and antiperoxide protection of cardiomyocytes. acute fatal hemorrhage; resuscitation; heart; lipid peroxidation