Use of the 24-lead "standard" electrocardiogram to identify the site of acute coronary occlusion

This review presents the added value for diagnosis of acute ischemia/infarction of considering ST elevation in the 12 inverted leads (-I, -II, -II, -aVR, etc) of the standard electrocardiogram in addition to ST elevation in 12 positive leads. A small number of studies have been published showing substantial increases in sensitivity at the "cost of' slight decreases in specificity. One recent study indicated that only 7 of the inverted leads should be considered, yielding a "19-lead electrocardiogram" encompassing the following leads (presented here in the logical secquences): -III, aVL, I, -aVR, II, aVF, III, -aVL, -I, aVR; and V1, V2, V3, V4, V5, V6, -V1, -V2, -V3. Studies have to be performed to establish the thresholds that should be applied to these leads for achievement of sensitivity/specificity.