DETECTION OF RIGHT-VENTRICULAR ISCHEMIA DURING CORONARY SURGERY BY MEANS OF A RIGHT PRECORDIAL LEAD

This study was designed to determine the intra-operative incidence of right-sided ventricular ischaemia and any association with left ventri cular ischaemia. In 60 patients, undergoing coronary artery bypass gra fting surgery, a rig ht-sided precordia I lead V5R was used. ST segmen t deviation of more than 1 mm in V5R was considered significant for my ocardial ischaemia. Right ventricular ischaemia occurred in 14 patient s (23.3%) but was not associated with left ventricular inferior wa II ischaemia. In 4 patients (6.6%) presenting with right ventricular isch aemia, ischaemia of the left inferior wall also developed but in all c ases was transient and disappeared by the end of surgery. No myocardia l infarction was detected in the post-operative period. The present st udy showed that the use of a right-sided lead may improve intra-operat ive electrocardiographic monitoring, by revealing ischaemia in those p atients in whom ECG abnormalities were not detected by conventional le ads. The transient right ventricular ischaemia recorded in this study was probably related to a reduced hypothermic protection of the right ventricle during aortic cross clamping.