BACKGROUND In the prognostic stratification of patients affected by AMI is important to evaluate, besides the assessment of left ventricular function and residual ischemia, the presence of electrophysiological instability. METHODS We have analysed 15 patients all affected by AMI complicated by early ventricular fibrillation. During the hospital phase we evaluated the E.F.% (ECHO) and the presence of late ventricular potentials (SAECG). After hospital discharge we followed up the patients for 6 months. RESULTS None of the patients died during the hospital phase while the posthospital cardiac mortality was 20%. The three patients dead during the follow-up had an AMI localized in the anterolateral wall of the left ventricle, an E.F.% less than 40% and LVP positive in the hospital phase. Besides the clinical course was complicated by cardiac failure. CONCLUSIONS We conclude that these three patients are a "high risk profile subgroup" and should be submitted to extensive evaluation with cardiac catheterization, coronary arteriography and programmed ventricular stimulation.