Salam N Asfar@ & Jasim M Salman#
@MB, ChB, MSc, Professor of Anesthesiology, College of Medicine, University of Basrah, Basrah, Iraq. #MB,ChB, DA, FICMS, Lecturer & Consultant Anesthesiologist, Basrah University and AlSadir Teaching Hospital, Basrah.
lose and continuous monitoring of patients at risk of myocardial ischaemia during anaesthesia is necessary as ischaemia represents 1% of all reported anaesthesia incidents1.
It is well recognized that even sophisticated ECG devices with automated segment analysis detect only a proportion of ischaemic events1,2. Furthermore, electronic filtering, lead selection, the number of leads monitored, and only intermittent checking of the ECG trace may reduce this still further2,3. Correct lead selection is particularly important and a full 12-lead ECG, although often impractical intraoperatively, remains the ‘‘gold standard’’ if accurate electrical diagnosis is required. For the high risk patient, intraoperative monitoring of leads V5 and V4 and II (in that order of priority) is likely to optimize the chances of ischaemia detection, but requires a more complex system than the usual 3 lead ECG in common use which is insensitive4,5.
The diagnosis of myocardial ischemia is often difficult because most occur without symptoms in anesthetized or sedated patients, ECG changes are slight and/or transient, and the creatine kinase has limited sensitivity and specificity because of coexisting skeletal muscle injury, but cardiac troponin assays have more specificity6.