Continuous ambulatory ECG monitoring in the perioperative period: relationship of preoperative status and outcome.

We have used continuous ambulatory electrocardiography in the perioperative period to monitor 108 patients with known cardiovascular disease undergoing non-cardiac surgery. There was a high incidence of ischaemic ST segment changes and ventricular arrhythmias. For the group as a whole, anaesthesia and surgery were followed by increased ventricular ectopic activity, but did not worsen myocardial ischaemia. However, the mean duration of ischaemic ST segment changes was increased significantly in those patients with treated hypertension. Of the risk factors considered, preoperative ischaemia and peroperative systolic arterial pressure were significant correlates with postoperative myocardial ischaemia.