ІgnatkinaО.; FEDKO, I.; LYSENKO, N. THE INFLUENCE OF ENALAPRIL MALEAT AND METOPROLOL TREATMENT ON HEMODYNAMICS AND HEART RATE VARIABILITY INDECES AMONG PATIENTS WITH CHRONIC HEART FAILURE IN DIFFERENT AGES GROUP. The Journal of V. N. Karazin Kharkiv National University, series "Medicine", n. 6, p. 44-49, 11.