Original article Value of intraoperative transoesophageal echocardiography in monitoring left ventricular function in patients undergoing elective coronary artery bypass grafting

Abstract

Background: Intraoperative transoesophageal echocardiography (IOTEE) is an integral part of many cardiac surgical procedures and is employed during major non-cardiac operations to monitor cardiac performance, particularly in high-risk patients. In the case of elective coronary artery bypass grafting (CABG) procedures this examination is performed according to experience and availability in a given centre.
Aim: To evaluate the value of IOTEE in monitoring left ventricular (LV) function in patients undergoing elective CABG with the use of cardiopulmonary bypass (CPB).
Methods: In fifty five patients (mean 66 ± 9 years), mean EuroSCORE: 4.5 ± 2.9 scheduled for elective CABG in CPB, IOTEE was performed after induction of anaesthesia, 5 and 30 min after weaning from CPB. Intraoperative parameters of LV function and volume (EDV/BSA) were compared with the data obtained by transthoracic echocardiography (TTE) performed before and 30 days after surgery.
Results: Significant depression of LV ejection fraction (LVEF) was found after induction of aesthesia (decline from 52.2 ± 11.2% to 49.8 ± 11.5%, p = 0.003). Subsequent improvement of LVEF was noticed at 1-month follow-up (p = 0.01). The highest wall motion score index (WMSI) (1.5 ± 0.43) was found after weaning from CPB, the lowest at follow-up (1.36 ± 0.4). Change of EF and WMSI at each stage of examination was significant (p < 0.001). Significant decrease of EDV/BSA was found 30 min after weaning from CPB (decline from 53.5 ± 23.2 to 49.1 ± 21.9 ml/m², p = 0.05). Significant depression of EF 5 min after weaning from CPB was detected only in patients with CPB time longer than 120 min (decline of 4.2%, p = 0.001).
Conclusion: Intraoperative transoesophageal echocordiography during elective CABG allows one to control difficult stages of the surgical procedure and to select patients at risk of perioperative haemodynamic deterioration. Our study supports the routine application of IOTEE in elective CABG.