Noninvasive assessment of reperfusion after fibrinolytic therapy for acutemyocardial infarction

Assessment of reperfusion by the 12-lead electrocardiogram (ECG) or biochem ical markers is limited by suboptimal sensitivity and/or specificity, Body surface mapping (BSM) improves the spatial sampling of the 12-lead EGG. Ser ial 12-lead ECGs and 64-lead anterior BSMs were recorded from 67 patients w ith acute myocardial infarction undergoing coronary angiography 90 minutes after fibrinolytic therapy, ECG-1 and BSM-1 were recorded before/shortly af ter therapy (median 18 minutes). ECG-2 and BSM-2 were recorded after the 90 -minute angiogram (median 30 minutes). The maximum ST elevation on EGG-I wa s noted and greater than or equal to 30% ST resolution on ECG-2 was taken t o represent partial/complete reperfusion, patients were randomly divided in to a training set and validation set. Isointegral and isopotential ST-T var iables from BSMs of training-set patients were compared with Thrombolysis I n Myocardial Infarction (TIMI) trial Flow using discriminant analysis to id entify which variables best classified reperfusion, Reperfusion (TIMI 2/3 f low) occurred in 32 of 34 training-set patients and in 29 of 33 validation- set patients. In the training set, greater than or equal to 30% ST resoluti on correctly classified reperfusion with 72% sensitivity (23 of 32) and 50% specificity (1 of 2), In the validation set, greater than or equal to 30% ST resolution classified reperfusion with 59% sensitivity (17 of 29) and 50 % specificity (2 of 4), In comparison, a model containing 24 BSM variables correctly classified all training-set patients, and when prospectively test ed in the validation-set, correctly classified 28 of 29 patients who achiev ed reperfusion (97% sensitivity) and all 4 patients who foiled to reperfuse (p = 0.035), In conclusion, BSM is more useful than the 12-lead ECG for no ninvasive assessment of reperfusion after fibrinolytic therapy for acute my ocardial infarction. (C) 2000 by Excerpta Medica, Inc.