Best ECG leads for diagnosing acute myocardial infarction by multivariate analysis of body surface potential maps

The authors compared 120-lead body surface potential map (BSPM) data from 131 patients with acute myocardial infarction (MI) and 159 normal control subjects (N). The MI population was stratified according to the location of ventricular wall motion abnormalities using technetium-99m-labeled blood pool imaging into 76 patients with anterior MI (AMI), 32 patients with inferior MI (IMI), and 23 patients with posterior MI (PMI). Stepwise discriminant analysis was performed for each pairwise comparison (AMI vs N, IMI vs. N, and PMI vs. N) using as measurements the ST magnitude in 120 electrode sites from each individual. Two leads from areas with the most abnormal ST changes achieved optimal classification in each MI class, and five of these six leads were outside the precordial electrode positions. In each bigroup classification, the first and best measurement corresponded to ST depression while the second represented ST elevation. Sensitivities at a specificity level of 95% were 82% for AMI, 93% for PMI, and 100% for IMI