[Comparison of two-dimensional echocardiography with 201T1-single photon emission computed tomography for evaluating the myocardial infarct zone].

The reliability of measuring the myocardial infarct zone by two-dimensional echocardiography (2 DE) was compared with that by regional myocardial blood flow as evaluated by single photon emission computed tomography (SPECT) in 47 patients with old myocardial infarction, with ventricular aneurysm (An group; n = 15), and without ventricular aneurysm (Non-An group; n = 32). Short-axis images of the left ventricle at the level of the mitral valve, the papillary muscles, and the apex were obtained both by 2DE and SPECT. The left ventricular wall was divided into 36 segments in 2DE and 40 segments in SPECT with reference points at the posterior end of the right side of the interventricular septum. The segments in which the radial shortening on 2DE and the 201Tl uptake index on SPECT were below one standard deviation from the means of 10 normal subjects were defined as those with abnormal wall motion and hypoperfused areas, respectively. The relationships between these findings were studied. The extent of apical movement was measured by left ventricular cineangiography in each case, and was compared between the An and Non-An groups. 1. Wall motion abnormalities on 2DE and hypoperfusion on SPECT showed a correspondence of 81% in the An group and 78% in the Non-An group at the level of the mitral valve, and 78% in the An group and 76% in the Non-An group at the papillary muscle level. However, a better correspondence was observed in the An group (84%) as compared to the Non-An group (64%) at the level of the apex. 2. Apical movement assessed by cineangiography showed more extensive changes in the Non-An group than in the An group (2.3 +/- 0.9 mm vs 4.1 +/- 1.7 mm in the RAO view, 2.4 +/- 1.9 mm vs 5.3 +/- 2.1 mm in the LAO view). From these observations, it was suspected that the cause of disparity between radial shortening and the 201Tl uptake index at the level of the apex is related to the cardiac movement of the apex toward the base during systole. 3. Since wall motion abnormalities demonstrated by radial shortening (2DE) and hypoperfusion indicated by the 201Tl uptake index (SPECT) generally corresponded well, 2DE was thought to be a useful method for evaluating myocardial infarct zone.