M-mode echocardiography was used to study left ventricular (LV) function in 25 patients with congestive cardiomyopathy (CC). Good discrimination of patients with CC from a control group of normal subjects was possible using echocardiographic parameters. Symptomatic patients (group II) with CC had a significantly larger LV end-diastolic diameter (LVED) than the asymptomatic ones (group 1) but the differences in the shortening fraction (SF), ejection fraction (EF), and mean velocity of circumferential fiber shortening (Vcf) were not statistically significant. Asymptomatic patients showed significant differences from normal in LVED, SF, EF and Vcf. End-systolic wall stress is a quantitative index of true myocardial afterload that can be plotted against LV end-systolic diameter to give an index of contractility independent of loading conditions. End-systolic wall stress in normal subjects (64.80 +/- 19.50 X 10(3) dyn/cm2) was significantly lower than in patients with CC (169.6 +/- 13.43 X 10(3) dyn/cm2). In conclusion the LV echocardiographic parameters can be conveniently combined to provide a good recognition and estimation of patients with CC, even in early stages.