Asymptomatic cardiac ischemia, frequently designated as silent myocardial ischemia, refers to episodes of objectively demonstrable transient ischemia in the absence of symptoms. Annually, more than one million patients suffer acute myocardial infarction. Of the approximately 700,000 who are discharged alive from the hospital, as many as 180,000 will be asymptomatic but have evidence of myocardial ischemia on a pre-discharge exercise test. Asymptomatic ischemia has been linked with sudden death or myocardial infarction. It is estimated that in the United States over six million patients have chronic, symptomatic coronary heart disease and up to three million of these may exhibit transient asymptomatic myocardial ischemia. Asymptomatic ischemia is thought to be present in the majority of coronary heart disease patients with stable angina pectoris, over 70 percent of all ischemic episodes being asymptomatic. Asymptomatic ischemia following myocardial infarction or in the presence of chronic stable angina may be associated with substantially increased morbidity and mortality