Prevalence and clinical significance of silent myocardial ischemia.
Accumulating data indicate that silent ischemia is a common accompaniment of coronary artery disease. In the population at large, studies estimate that 2-4% of middle-aged men have asymptomatic coronary artery disease and silent ischemia on treadmill testing. In patients with known coronary artery disease, positive treadmill tests are unaccompanied by pain about 34% of the time. In patients with stable angina pectoris, silent ischemia comprises about 70% of total ischemic events. This frequency approaches 80% in patients with unstable angina. About 20-30% of all myocardial infarctions are silent. Of patients who survive myocardial infarction, about 5% have silent ischemia on early treadmill testing, which signals an adverse prognosis. Overall, the presence of ischemia increases the risk for any subset of patients with coronary disease. Furthermore, the risk is the same whether the ischemia is silent or symptomatic. In summary, silent ischemia is common in patients with coronary disease and adversely affects prognosis, especially in high-risk patients.
Parmley
W W
WW
University of California, San Francisco.
D003327:Coronary Disease / Q000453:epidemiology*; D004562:Electrocardiography; D005080:Exercise Test; D006801:Humans; D015995:Prevalence; D011379:Prognosis; D012307:Risk Factors