BACKGROUND: Aim of the study was to evaluate the prognostic and decision making value of Holter detected myocardial ischemia after acute myocardial infarction in comparison with clinically detected postinfarction angina and exercise test. METHODS: To this aim the patients consecutively admitted to our coronary care unit with acute myocardial infarction during one year were retrospectively evaluated. One hundred and eighty-nine patients (age 70+/-11 years, 137 male and 51 female) had a 24 hour Holter monitoring. One-year follow up of these patients was obtained. RESULTS: Myocardial ischemia was detected by Holter monitoring in 21 patients (11%), 4 with and 17 without angina. Symptom limited exercise test was obtained before discharge in 116 patients (62%): 45% were positive, 42% non-diagnostic and 13 negative for myocardial ischemia. Post infarction angina was present in 15 patients (9%). Patients with Holter detected myocardial ischemia were older (73+/-10 vs 66+/-11 years, p<0.05) and had higher prevalence of both angina and positive exercise test (p<0.01). One-year follow up was obtained in 186 patients. Holter detected myocardial ischemia positive predictive value for death or reinfarction was 15%, negative predictive value was 90%, similar to the absence of angina (90%) and the absence of positive exercise test (93%). Angina and exercise test identified 62% of patients with Holter detected myocardial ischemia. Residual myocardial ischemia was exclusively observed by Holter monitoring in 4% of the population, particularly in 1 patients with and 7 without exercise test. CONCLUSIONS: The additive contribution of Holter detected myocardial ischemia in the prognosis and decision making of post infarction patients is rather scanty.