The data are reported on the pattern of the T3/T4 ratio in patients with acute myocardial infarction throughout the hospitalization period. Different forms of dysthyreosis were identified related to the period of the disease and its clinical outcome. The first days of the disease were characterized by low levels of T3 and an increase in the content of total T4. Further transformation of the dysthyreosis depended on the outcome of myocardial infarction at the hospitalization stage. In myocardial infarction patients the levels of total T4 elevated in the presence of angina attacks. An increase in the concentration of total T4 was observed several hours before the angina attack.