DISCRIMINANT FUNCTION-ANALYSIS OF BODY-SURFACE POTENTIAL MAPS IN ACUTE MYOCARDIAL-INFARCTION

Using a newly developed 64-electrode portable mapping device, QRS and ST-T isointegral maps were compared in 194 control subjects and 101 pa tients. One hundred ninety-four control subjects (mean age, 48 years; 120 men) with no history of cardiac disease were selected randomly and mapped. One hundred one patients (mean age, 62 years; 77 men) were ma pped at presentation of chest pain suggestive of first myocardial infa rction (MI); all patients had classic 12-lead electrocardiographic fin dings-46 with anterior and 55 with inferior MI. The diagnosis was conf irmed in all cases by a significant rise in serial cardiac enzymes. Th e mean delay between onset of chest pain to map recording was 163 minu tes. Of the 101 patients, 78 were first mapped outside the hospital. A pplying discriminant function analysis to the isointegral measurements made on the control subjects and on the first map of MI patients achi eved a correct classification of 97% of the control subjects (189 of 1 94) and 72% of the anterior (33 of 46) and 76% of the inferior (42 of 55) MI groups. This preliminary study suggests that discriminant funct ion analysis, based on isointegral maps, not only provides a method of separating control subjects from MI patients but that it can also dif ferentiate between types of infarct. Further studies are required to i mprove the predictive values of discriminant function and to extend th e methodology to assess both the site and size of MI.