Changes in heart geometry and function during off-pump coronary artery bypass grafting / 中华麻醉学杂志

ABSTRACT

Objective To assess the changes in heart geometry and function during off-pump coronary artery bypass grafting(CABG).Methods Thirty ASAⅡorⅢpatients(24 males,6 females)aged 50-78 undergoing elective off-pump CABG were studied.After induction of anesthesia and tracheal intubation a catheter which was connected to the monitor measuring continuous cardiac output(CCO),mixed venous blood oxygen saturation(S(?)O_2)and CEDV was placed via right internal jugular vein and the probe of multi-phase transesophageal echocardiograph(TEE)(Sonos HP 2500)was inserted in the esophagus.The distance between the probe and the incisors was between 34-45 cm.The hemodynamic variables and TEE parameters were recorded when epicardium was opened(T_1,baseline)when the octopus tissue stabilizer was placed during anastomosis between the graft vessel and left anterior descending artery(LAD)(T_2)left circumflex artery(LCX)(T_3)and right coronary artery(RCA)(T_4)and when the anastomoses between the vessel grafts and aorta was completed (T_5).Results At T_2 the mitral valve deceleration time(DT_1)and the blood flow through the mitral valve(Q_1) were decreased significantly as compared with the baseline(T_1);MAP was significantly decreased while HR and CVP were increased(P＜0.05).At T_3 the left and right ventricular end-diastolic diameter(LVEDD,RVEDD), tricuspid valve diameter(TVD)and the blood flow through Q_1 and tricuspid valve(Q_2)were significantly decreased as compared to the baseline values at T_1.The mitral valve E/A ratio was increased while the tricuspid valve E/A ratio was decreased(P＜0.05).The MAP,S(?)O_2,right ventricular end-systolic and end-diastolic volume(RVESV,RVEDV)and right ventricular ejection fraction were significantly decreased while HR and CVP were increased at T_3 as compared to the baseline at T_1.At T_4 LVESD,LVEDD,MVD,tricuspid valve E/A ratio and Q_1 were significantly decreased as compared to the baseline at T_1(P＜0.05).MAP,MPAP,SV,S(?)O_2, RVEF,RVESV and RVEDV were significantly decreased while HR and CVP were increased(P＜0.05).At T_5 all the TEE and hemodynamic parameters returned to the baseline valves at T_1.Conclusion During anastomoses between graft vessels and LAD,LCX and RCA,both left and right ventricles are compared to some extent and the heart function is impaired temporarily but returns to the baseline after the anastomoses are completed.