Myocardial ischaemia associated with general anaesthesia. A review of clinical studies.

The incidence of perioperative myocardial ischaemia in patients with coronary artery disease, as reported in the literature, varies widely (tables I, II). Much of the confusion surrounding this issue can probably be related to differences in patient populations studied, study programmes and techniques used to establish ischaemia (table III). Until recently, efforts to avoid myocardial ischaemia concentrated primarily upon decreasing myocardial oxygen demand by controlling hypertension and tachycardia. It was accepted widely that a reduction of arterial pressure was safe in patients with coronary artery disease (CAD), provided the contractility of the heart, and hence oxygen consumption, were depressed proportionally by the anaesthetic agent [18]. More recently, it has been recognized that myocardial oxygenation may, under some circumstances, be impaired, despite apparently normal systemic haemodynamics. When the first reports of non-haemodynamically related myocardial ischaemia, associated with inhalation anaesthesia in man, appeared in 1983 [52], it was not surprising that these data stimulated many investigators [4,36-39] and created the impetus for intense research in the field.