Intra-operative assessment of myocardial ischaemia during general surgery by transoesophageal echocardiography: present state and future perspectives.

This paper reviews the present state and future perspectives of the peri-operative application of Transoesophageal Echocardiography (TEE) for early detection of myocardial ischaemia during general surgery. The increasing clinical relevance of this problem parallels the progressively higher frequency of surgery performed in patients at relatively high cardiovascular risk, due to a longer life-span and improved anaesthetic techniques. TEE potentially provides a powerful method for detailed cardiac monitoring in patients undergoing general surgery. The detection of a new regional asynergy during echocardiographic monitoring represents an early and reliable marker of myocardial ischaemia. The sensitivity, specificity and feasibility of TEE monitoring of intraoperative myocardial function and ischaemia will be outlined and compared with those of ECG and invasive monitoring. Problems related to the interpretation of intra-operative findings, with special reference to possible non-ischaemic mechanisms responsible for intra-operative regional asynergies--which can decrease the specificity of this method--are considered. Though still under investigation, the potential contribution of ultrasonic tissue characterisation of the asynergic ventricular wall as an additional, or even alternative, marker of myocardial ischaemia, is discussed. Finally, educational problems related to the new tasks facing the anaesthesiologist involved in intra-operative echo-Doppler evaluation of cardiac function are also foreseen.