BACKGROUND: Coronary artery bypass grafting without cardiopulmonary bypass (Off-Pump Coronary Artery Bypass Grafting, OPCAB) causes significant hemodynamic derangement by displacement of the beating heart. The purpose of this study was to analyze the hemodynamic changes caused in relation to grafted arteries by displacing the heart and stabilizing the coronary arteries in patients undergoing OPCAB. METHODS: Nineteen patients underwent OPCAB using two deep pericardial sutures and tissue stabilizers (Octopus Tissue Stabilization Syetem, Medtronic, USA). The hemodynamic variables were obtained after induction of anesthesia, after deep pericardial sutures, before and after anastomosis of each coronary artery during epicardial stabilizing, after sternal closure, and after postoperative 6 hours and 12 hours in the intensive care unit. RESULTS: The hemodynamic variables were maintained with the Trendelenburg position, volume loading and low dose vasopressors after deep pericardial stay sutures. Displacement of the heart and placement of the stabilizer on all coronary territories except the obtuse marginal artery before anastomosis showed no significant difference in hemodynamics compared with baseline. Positioning for the graft to the obtuse marginal artery decreased cardiac index (1.6+/-0.4 L/min/m2) and stroke index (27.6+/-9.9 L/beat/m2) and increased systemic vascular resistance (2318.9+/-673.7 dyne sec cm(-5)), resulting in hemodynamic compromise (P<0.01). There were no significant hemodynamic and electrocardiographic changes before or after grafting of other coronary arteries but there was a significant increase in cardiac index after postoperative 6 and 12 hours compared with baseline values (P<0.05). CONCLUSIONS: Although the complete revascularization of most coronary arteries is feasible on the beating heart without significant hemodynamic compromise with minimal vasopressor support, the positioning for the graft to the obtuse marginal artery needs special attention because two deep pericardial stay sutures and Octopus tissue stabilizers on the obtuse marginal artery territory induce significant hemodynamic disturbances.