A comparative study of body surface isopotential mapping and the electrocardiogram in diagnosing of myocardial...

It is important to determine the location of the infarcted area by body surface isopotential mapping (MAP), but at present there is no definite method to accomplish this. The present authors reported that they were able to estimate the infarcted area by MAP, and so it became necessary to confirm the reliability of their method. Initially, in a retrospective study using 50 cases, a comparison was made between the location of the infarcted area estimated by MAP and that estimated by 12-lead ECG to determine the size of the infarcted area of a region in which positive findings were obtained to determine the location of infarction. Criterion A (the infarcted area occupies more than half of a region in which positive findings are obtained by MAP) in a previous study was too severe for MAP, and Criterion B (the infarcted area occupies more than one third of a region in which positive findings are obtained) was adequate as a positive finding by MAP after comparison with the 12-lead ECG. This was confirmed in 40 cases in a prospective study. Secondly, in order to assess the superiority of MAP to the 12-lead ECG, the sensitivity, specificity and others of MAP and those of the 12-lead ECG to a scintigram using thallium-201 (SCG) were calculated. The sensitivity and negative predictive value of MAP to SCG were superior to that of ECG to SCG in the lateral, inferior and posterior walls, and it was suggested that MAP was more sensitive than 12-lead ECG in detecting the location of myocardial infarction.