Two dimensional echocardiography (2-DE) and 201T1 single photon emission computed tomography (SPECT) were performed in 51 patients with acute myocardial infarction (AMI), and the results were compared with those obtained by left ventriculography (LVG). After Loh et al., the image of the left ventricular (LV) wall was divided into 9 segments. LV wall motion and T1 uptake in each segment were evaluated according to their severity and assigned scores from 1 to 5. The degree of global abnormality in each patient as determined by each method was obtained by the sum of the scores assigned to the 9 segments, and expressed as sigma LVG, sigma 2-DE or sigma SPECT, sigma'LVG, sigma'2-DE and sigma'SPECT were also measured for 5 LV segments which were equivalent to the right anterior oblique view in LVG. Ejection fraction (EF) was measured by LVG using Kennedy's method. The results may be summarized as follows: 1) The mean value of sigma 2-DE (sigma 2-DE) was almost the same as that of sigma LVG (sigma LVG), but that of sigma SPECT (sigma SPECT) was significantly higher than sigma LVG (p less than 0.05). 2) The correlation coefficient of sigma LVG with sigma 2-DE was 0.85 (p less than 0.001) and with sigma SPECT, 0.72 (p less than 0.001). 3) sigma'LVG, sigma'2-DE and sigma'SPECT correlated significantly with EF (LVG: r = 0.82; 2-DE: r = 0.74; SPECT: r = 0.63). 4) Using multiple regression analysis, sigma LVG and EF were estimated from the sum of the 2-DE and SPECT scores in each segment and expressed as sigma LVG and EF.(ABSTRACT TRUNCATED AT 250 WORDS)