title: Transient ischemia in angina pectoris: frequent silent events with everyday activities.
abstract: To help characterize episodes of transient myocardial ischemia, 80 patients with chronic stable angina and evidence of obstructive coronary disease were studied by ambulatory electrocardiographic (ECG) monitoring outside the hospital to detect both symptomatic and asymptomatic episodes of ST-segment depression. In addition, patients were tested on an outpatient basis by means of positron emission tomography to assess regional coronary blood flow under different conditions. All patients showed ECG evidence of transient ischemia, with or without symptoms, while active outside the hospital. In-hospital testing showed that symptomatic and asymptomatic disturbances in regional coronary blood flow occurred with normal everyday activities and were not caused by physical exertion involving marked increases in heart rate and blood pressure. Most of these provocations were followed by a decrease in coronary blood flow in a poststenotic segment of myocardium and, like the ischemic events monitored out of hospital, the majority were silent. Many of these features characterizing the activity of ischemic heart disease may not be apparent from a patient's anginal history or results of hospital diagnostic testing.
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D000368:Aged; D000553:Ambulatory Care; D000787:Angina Pectoris / Q000503:physiopathology*; D001157:Arterial Occlusive Diseases / Q000503:physiopathology; D001783:Blood Flow Velocity; D001795:Blood Pressure Determination; D003080:Cold Temperature; D003326:Coronary Circulation; D003327:Coronary Disease / Q000503:physiopathology*; D004562:Electrocardiography; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D013997:Time Factors