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Objectives:To observe and analyze the variations of right ventricular function and hemodynamic indexes alteration in off-pump coronary artery bypass graft (OPCABG) surgery, and to compare the hemodynamic indexes originated from both pressure and volume respectively. The correlation between right ventricular end-diastolic volume index (RVEDVI) and cardiac index (CI) is to be analyzed. By present study, the improvement of perioperative management and a better understanding of significance of right ventricle functional monitoring in OPCABG are expected.Methods:The present study included 50 patients undergoing elective OPCABG. A thermodilution pulmonary artery catheter was inserted after anesthesia induction. Following data were collected: mean arterial pressure (MAP), heart rate(HR), mean pulmonary arterial pressure (MPAP), pulmonary arterial wedge pressure (PAWP), central venous pressure (CVP), cardiac output (CO), cardiac output index (CI), right ventricular ejection fraction (RVEF), right ventricular end-diastolic volume index (RVEDVI), pulmonary vascular resistance index(PVRI), systemic vascular resistance index(SVRI), RV stroke work index(RVSWI), LV stroke work index(LVSWI)and oxygen saturation of mixed venous blood(SvO2). The hemodynamic variables were measured after the epicardium opening (baseline),5 min after the heart was positioned for each coronary anastomosis (included LAD, LCX, PDA) and after the sternum closing. The ECG alteration and inotropic agent consumption were recorded at each time point.Results:The MAP and HR did not changed significantly, while the MPAP,PAWP and CVP increased during anastomoses of LAD, LCX and PDA. There were no significant changes in CI, RVEF, RVEDVI during anastomosis of LAD. However, the significant reduced CI, RVEF and RVEDVI were observed during anastomosis of LCX and PDA. Dopamine and phenylephrine consumption were significant higher during the anastomosis of LCX than in other periods (P<0.05). ST segment and cardiac rhythm were not changed significantly during OPCABG. The hemodynamic parameters and right ventricular function parameters can be gradually returning to base line after the sternum closing. According to the results of present study, pressure index (CVP) and volumetric index (EDVI) were not accordant. The correlation of the two types of indexes was poor (r=-0.054,-0.101,-0.039). EDVI and CI had no significant correlation (r= 0.293).Conclusions:The displacement of beating heart for positioning during LCX and PDA anastomosis cause significant derangement of right ventricular function and hemodynamic indexes in patients undergoing OPCABG. Meanwhile the variations of the pressure index and the volumetric index are not accordant. It is very significant to monitor the change of right ventricular function and hemodynamic indexes in OPCABG, which can help to judge the actual right ventricular preload and the real reason of hemodynamic derangement.
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