The single precordial lead for ST segment monitoring: comparison with the multiple lead map.

ST segment elevation, used as an index of the relative extent of myocardial ischemic injury, was measured using a single precordial lead located at the point of maximum ST elevation. ST changes were followed for two hours after acute coronary occlusion in pigs, and were compared to the sum of ST elevation recorded with an 18 lead precordial map. Some animals were subjected to Reperfusion (n = 12), others to infarct extension (n = 10), while a control group (n = 9) was followed without an ST-modifying intervention. Correlation between sigmaST and ST in the single lead was good, with a correlation coefficient of 0.844 at 360 points of comparison. Time to peak ST elevation using the single lead technique was comparable to that using the 18 lead map. Changes in the ST elevation using both techniques were similarly reduced following reperfusion, increased following extension, and followed a similar downslope pattern in the unmodified infarct group. This single lead technique offers the advantage of simplicity of use without sacrifice of accuracy. Its use can facilitate clinical studies of myocardial ischemic injury and its modification.