RESUMO
BACKGROUND: Hemodynamic derangement during the displacement of the beating heart in off-pump coronary artery bypass graft surgery (OPCAB) might be related with right ventricular (RV) dysfunction. This study evaluated the influence of displacing and stabilizing the heart, for the anastomosis of coronary arteries, on hemodynamic alterations and RV function in patients undergoing OPCAB. METHODS: Twenty patients with triple vessel coronary artery disease underwent OPCAB using single pericardial sutures: a tissue stabilizer was included. The hemodynamic variables and right ventricular ejection fraction (RVEF) were obtained using a right-heart ejection fraction thermodilution pulmonary artery catheter after the induction of anesthesia, before and after anastomosis of each coronary artery and after sternal closure. RESULTS: No significant hemodynamic changes were observed during the displacement of the heart or the placement of a stabilizer on all of the coronary arteries, except the obtuse marginal artery (OM) before anastomosis. RVEF, left ventricular stroke work index (LVSWI), stroke volume index and cardiac index (CI) decreased and mean pulmonary artery pressure increased significantly whist positioning the graft to the OM. Right ventricular volumes were not significantly changed, although central venous pressure and pulmonary capillary wedge pressure increased. Changing CI had a close relationship with LVSWI (r2 = 0.537, P <0.05) but not with RVEF (r2 = 0.118). These hemodynamic compromises recovered to baseline values after sternal closure. CONCLUSIONS: The displacement of the beating heart for positioning during anastomosis of the graft to the OM caused significant hemodynamic instability and LV functional changes in addition to RV functional changes seemed to be responsible for hemodynamic derangements.