[Silent myocardial ischemia: a problem in diagnosis and treatment]

We tried to establish the incidence of silent myocardial ischemia (SMI) in the general population and also in patients with recognised ischemic heart disease. For this, purpose 2, 375 stress tests (ST) with Bruce protocol were reviewed, 364 were positive and those patients were divided in two groups: group I with SMI during the ST and group II with myocardial ischemia and angina during the ST. Coronary risk factors ergometric behaviour and angiographic factors were analysed. Group I had 263 patients with SMI (71%). Group II had 111 patients with ischemia and angina (29%) P less than 0.05; 90 patients had diabetes mellitus in group I and 19 in group II P less than 0.05. A previous myocardial infarction was registered in 157 patients from group I and 55 from group II P less than 0.05. The remaining coronary risks factors, ergometrics variables and significance and number of diseased coronary vessels were similar in both groups. We conclude that SMI is a frequent event in patients with ischemic heart disease. It represents probably the most frequent event in this disease. Previous myocardial infarction and diabetes mellitus may play an important role in the pathogenesis of SMI. The ST and Holter monitoring are dependable procedures for the identification of SMI and should be always performed specially in patients with high coronary risk factors. Once detecting SMI a therapeutic plan should be considered for medical, angioplastic or surgical procedures even in asymptomatic patients.