The body surface isopotential mapping of the QRS wave in myocardial infarction. a comparative study of the scintigram with thallium-201.

When body surface isopotential mapping (MAP) is used in clinical cases of myocardial infarction, it is necessary to determine the location of the infarcted area. The present authors presumed that the positive area of MAP in normal subjects, which was altered to a negative area of MAP in myocardial infarction, was the infarcted area. In order to confirm the presumed location of the infarcted area, the location of the infarcted area on MAP and the location of infarction presumed by the scintigram with thallium-201 (SCG) were compared. MAP was divided into ten regions and a comparison between the presence or absence of an infarcted area in each segment on the MAP and of abnormal findings in each segment of the SCG was made. Consequently, the highest percentage of agreement in each region of the segment in SCG was picked up, and each region on MAP which corresponded to the segment in SCG was determined. Thereafter, each segment of MAP was matched with a wall of the ventricle: region 1--the septum; region 2--the apex; region 3--the anterior wall; region 4--the posterior portion of the apex; the upper portion of region 5--the lateral wall; region 6, 8 and 10--the inferior wall; and region 7--the posterior wall. In this way, the classification of myocardial infarction was carried out in 51 cases.