Development and validation of ambulatory monitoring to characterize ischemic heart disease out of hospital.

The ST segment has long been used as a measure of experimental and clinical myocardial ischemia and injury. Ambulatory monitoring of the electrocardiogram makes recognition and quantification of both symptomatic and asymptomatic myocardial ischemia in patients with coronary artery disease possible. A body of evidence, including the known characteristics of ST-segment shifts in patients with and without coronary artery disease and validation studies with positron tomography, is presented to support the use of the electrocardiogram during dynamic activity as a valid marker of reversible myocardial ischemia. Recommendations for monitoring based on this information are provided.