Silent versus symptomatic myocardial ischemia during exercise testing: a comparison with coronary angiographic findings.

Two-hundred-and-eighty individuals with anginal complaints, without prior myocardial infarction and with a positive exercise stress test were divided into a group (n = 67) with exercise-induced silent myocardial ischemia and another group (n = 213) with exercise-induced angina pectoris. Both underwent coronary angiography and were compared with each other with respect to various exercise and angiographic parameters. Patients with exercise-induced silent ischemia attained a longer mean exercise duration (P less than 0.001), a higher peak exercise heart rate (P less than 0.0001) and a higher peak exercise rate pressure product (P less than 0.001) than patients with exercise-induced angina pectoris. In the latter group, more patients showed exercise-induced ST-segment depression greater than 2 mm (P less than 0.05). The group of patients with silent ischemia encompassed more individuals with normal coronary arteries (P less than 0.0001). More patients with exercise-induced angina pectoris had three-vessel disease (P less than 0.0001). The exclusion of patients with normal coronary arteries (23% in those with silent ischemia group and 6% in those with exercise-induced angina had no influence on the level of significance for peak heart rate, mean exercise duration and exercise duration greater than 10 min. Thus, in this population, exercise-induced silent myocardial ischemia is associated with better exercise performance and less extensive coronary arterial pathology than in exercise-induced angina pectoris.