Natural History of Silent Ischemia

T herapeutic decisions in patients with coronary artery disease are frequently based on the severity of chest pain despite the lack of correlation between severity of symptoms and prognosis. There are many circumstances in which objective evidence for myocardial ischemia is present but symptoms are absent. Episodes of so-called “silent myocardial ischemia” are very frequent in some patients with other manifestations of coronary heart disease; for example, patients with angina have no symptoms in 70 to 80 percent of all recorded ischemic episodes. While the overall incidence, spontaneous variability, and relationship of symptomatic to asymptomatic ischemia are largely unknown, this condition is being increasingly recognized. The purpose of this review is to discuss the clinical aspects of silent ischemia and the rationale for treatment (Fig 1). This information can be used to develop a strategy to help the clinician deal with this problem.