[Two-dimensional echocardiography in diagnosing the region of myocardial infarction: a comparative study by several independent examiners].

The efficacy of two-dimensional echocardiography in diagnosing the localization of myocardial infarction (MI) was studied by comparing the echocardiographic and pathological findings of 28 patients having MI. The ventricular wall was divided into 18 segments including three segments of the right ventricular wall. The regional wall motion abnormalities for each of the 504 segments were diagnosed by visual assessment. The echocardiographic recordings were reviewed individually by four examiners using the same protocol to assess the interobserver's variation. The receiver operating characteristics (ROC) curves differed by examiners. However, when the subjects were limited to anterior MI patients, the ROC curves established by the echo-trained physicians did not differ significantly. It was concluded that the echocardiographic diagnosis of regional wall motion by visual assessment has universal validity. Individual differences are thought mainly to depend on the sites of infarction. Sensitivities for detecting transmural (TM), non-transmural (non-TM) infarcted segments and intact segments were 90, 70 and 70%, respectively. Most of the underestimated TM or overestimated intact segments corresponded to the sites adjacent to MI. As the unexpectedly misdiagnosed segments, the mimic inward motion of the inferior wall drawn by the intact anteroapical wall was observed in a inferior MI patient, or the mimic anterior motion of the anteroapical wall by a swinging motion of the heart, or the paradoxical motion of the interventricular septum was observed in a right ventricular MI case. In the two third of the overestimated non-TM segments, it was considered that the wall motion was affected by the myocardial ischemia, which was not revealed by pathological examination. The underestimated non-TM segments located adjacent to the intact segments or opposite to the severely ischemic segments. From the echocardiographic viewpoint, nearly 90% of segments showing akinetic or dyskinetic motion had MI. However, one third of segments diagnosed as normal were actually MI segments.