The aim of the study was to compare the effect of heart rate control with combination of Β-blocker and ivabradine and Β-blocker alone upon systolic function, exercise tolerance and hemodynamic support of physical activity in patients with Q-wave myocardial infarction (MI), left ventricular (LV) ejection fraction (EF) < 45% and sinus rhythm at the early (1 month) and later (6 months) periods. We examined 28 patients with first Q-wave MI with an EF < 45%, resting heart rate (HR) > 70 bpm and „S. Killip class I.II on the first day of the disease, all of whom received reperfusion therapy. As part of the standard therapy, patients in group 1 (n=12) received metoprolol tartrate (average daily dose 105.4±5.2 mg). Patients in group 2 (n=16), apart from metoprolol tartrate (average daily dose 55.3±1.7 mg), received ivabradine (average daily dose 11.3±1.5 mg), starting from 4.6 days of disease. Studies of exercise tolerance and echocardiographic parameters were performed in all patients at 28 days and in 6 months. After titration of Β-blocker and ivabradine in both groups HR was equally decreased at 28 day and 6 months (all P>0.05). The control of HR with ivabradine added to the Β-blocker, compared with monotherapy with higher doses of Β-blocker, contributes to improving LV systolic function and exercise tolerance. At the same relative increase of exercise tolerance at 6 months combination therapy was associated with larger relative increase in heart rate and double product at peak exercise.