Longitudinal (Natural History) Studies of Silent Myocardial Ischemia
It is known that about 25% of myocardial infarctions occur without associated pain (1). Recent reports of unsuspected, frequent and prolonged episodes of asymptomatic ST depression (ASTD) during Holter recordings made in patients with clinical angina pectoris and positive exercise tests have raised important issues for the evaluation and treatment of coronary disease. The traditional role of angina as the best indicator of myocardial ischemia may have to be reevaluated, since several studies have shown that ASTD occurs more frequently than symptomatic ischemia in many patients with coronary disease (2–11). Atrial pacing in patients with angina pectoris shows that angina is a relatively late event during myocardial ischemia (12). If ASTD reflects clinically meaningful ischemia, then overt angina represents only 25% of the total ischemic burden. Moreover, incomplete data suggest than an increased and clinically unsuspected risk may be conferred on patients who have frequent episodes of ASTD (13,14).
KeywordsCoronary Artery Bypass Graft Silent Myocardial Ischemia Ischemic Episode Reversible Perfusion Defect Silent Ischemia
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