The relative prognostic value of clinical heart failure and early M-mode and 2-dimensional echocardiographic indexes of left ventricular performance was compared in a study of 205 consecutive patients with acute myocardial infarction (AMI). Statistical analysis showed that an early wall motion score was a stronger predictor of 1-year mortality than the occurrence of clinical heart failure early, late or at any time during the hospital course of AMI. The finding of clinical heart failure had an independent prognostic value of intermediate strength. M-mode echocardiographic parameters only had a weak independent prognostic value, possibly related to their content of information on left ventricular end-systolic dimension.