Improved monitoring of myocardial ischaemia during major vascular surgery using transoesophageal echocardiography.

Abstract

As regional wall motion abnormality (RWA) is the first sign of ischaemia, transoesophageal echocardiography was evaluated as a monitoring device in 51 patients undergoing abdominal aortic surgery. Wall motion of the entire left ventricular wall (nine segments) was semiquantitatively evaluated 15 min before and after aortic cross-clamping and 3 h after declamping. In addition, limb lead II of the electrocardiogram was simultaneously recorded. At baseline, RWA was present in 16 patients (31%). New or worsened RWA 15 min after aortic cross-clamping was seen in 17 patients, of whom 11 had persistent RWA, i.e. it was still present 3 h after declamping. This was associated in seven patients with enzymatically documented myocardial infarction. Only one infarct patient demonstrated ST segment changes of more than 1 mm. Thus, a single electrocardiographic surface lead is insensitive for perioperative myocardial ischaemia detection. Furthermore, new and/or worsened RWA after aortic cross-clamping, which persists until 3 h after declamping, is, to a considerable degree, associated with perioperative infarction.