45 cases of direct revascularization were retrospectively and prospectively analyzed in patients with left ventricular ejection fraction ≤40%. All patients were divided into 2 groups: patients from the first group (n=25) were operated under parallel artificial circulation (AC); patients from the second group (n=20) were operated under AC on stopped heart. All operations were carried out under normothermic AC by one surgeon. Cold crystalloid-blood cardioplegia was used for cardiac arrest. Indices of central hemodynamics and oxygen transport were ascertained by thermodilution method using Swan-Ganz catheter, placed before the operation. In both groups normalization of central hemodynamics indices was observed after the operation. Increase of cardiac and stroke indices, performance of right and left ventricles were observed. Due to optimization of minute circulatory volume improvement of oxygen transport indices was observed as well. There were no any statistically significant differences in demands for adrenomimetic support between groups. Analysis of ECG and dynamics in injury biomarkers in postoperative period indicates no myocardial damage or statistically significant differences in laboratory data between groups. Still such integrated indices as duration of AC and amount of postoperative bed-days at hospital had statistically significant indices. Moreover in operations under parallel AC without cardioplegia there was no necessity in cardioversion while in operations on stopped heart electric cardioversion for sinus rhythm restoration was carried out in 38% of patients. It is drawn a conclusion that parallel AC in direct myocardial revascularization is safe and reliable and its application is reasonable in patients with low ejection fraction.