Clinical significance of exercise-induced silent myocardial ischemia in patients with coronary artery disease

Exercise-induced silent myocardial ischemia is a frequent feature in patients with coronary artery disease. The purpose of this study was to compare the clinical and angiographic characteristics of 269 patients who complained of chest pain during an exercise test (group I) with those of 204 who developed exercise-induced silent myocardial ischemia (group II). Group I patients more frequently had anginal symptoms of class III and IV of the Canadian Cardiovascular Society than did group II patients, who had milder symptoms (p < 0.001). The only angiographic difference observed between the two groups was a slightly but significantly higher left ventricular end-diastolic pressure in group II patients (p < 0.05), who also showed a longer exercise duration (p < 0.01) with a higher heart rate-systolic pressure product (p < 0.01) and more pronounced ST segment depression at peak exercise (p < 0.001). Moreover, ventricular ectopic beats during exercise were more frequently observed in group II patients (p < 0.05).