The Authors have examined the possibility for diagnostic and prognostic value of exercise stress test and of dynamic ecg in the identification of ventricular ectopic activity which represent a factor risk of sudden death. 41 male patients with IHD and Myocardial Infarction were given exercise stress test and Holter monitoring according to the usual methods. Both methods were useful to identify Pts with arrhythmias. The total incidence of ventricular ectopic beats was 78% with Holter and 46% with exercise test. Holter monitoring showed a major possibility to detect high degree arrhythmias (39%) against 9% of exercise test. Two methods are not comparable, not it was possible to demonstrate statistically significant incidence of ventricular ectopics with respect to the localization of M.I. 90% of Pts with positive exercise test (angina and/or ecg alterations) showed ventricular ectopic beats against 45% of Pts with negative exercise test. The association of ventricular ectopic beats in Holter and positive response to exercise test is highly predictable of sudden death. The results of investigation suggest the opportunity to evaluate Pts with MI by both methods, dynamic ecg and exercise stress test.