Echocardiographic findings of 11 patients with dilated cardiomyopathy (DCM) were compared with those of 11 patient with coronary triple vessel disease, who showed extensive left ventricular (LV) wall motion abnormalities (abnormal LV regional wall motion observed in more than six of seven segments as classified by AHA) and a dilated LV cavity (LVEDVI: 120 ml/m2 or greater), consistent with so-called ischemic cardiomyopathy (ICM). Short-axis two-dimensional echocardiograms of the left ventricle at the mitral valve, papillary muscle, and apical levels were divided equally into eight segments starting from the posterior aspect of the right side of the interventricular septum. Non-uniformity of LV regional wall motion abnormalities was demonstrated in seven patients (64%) with DCM and 11 patients (100%) with ICM, and that of LV regional wall motion abnormalities of more than two degrees was observed in one patient (9%) with DCM and nine patients (82%) with ICM. LV regional wall thinning was observed in two patients (18%) with DCM and 11 patients (100%) with ICM. Increased echo intensity of the LV regional wall was observed in only four patients with ICM. Two patients (18%) with DCM and 11 patients (100%) with ICM had episodes of chest pain and the former two had LV regional wall thinning, suggesting the possibility of post-myocarditis cardiomegaly. Abnormal Q waves in the electrocardiograms were observed in 10 patients (91%) with ICM and in two (18%) with DCM. Exercise ECG tests were positive in nine of 11 patients with ICM, but in none of the five DCM examined.(ABSTRACT TRUNCATED AT 250 WORDS)