[Unstable coronary disease--clinical course and significance of exercise tests in patients with left coronary artery stenosis].

This study aimed at evaluating predictive value of exercise tests in case of left coronary artery stenosis. The study involved 57 patients with left coronary artery stenosis, including 10 patients with isolated left main stenosis (group X), and 47 patients with left coronary artery stenosis and multivessel involvement (group Y). Unstable angina was staged according to Booth et al. classification as type I or II. Exercise tests were performed according to Bruce's protocol. Unstable angina of type I was diagnosed in 51 (89%) patients, and type II in 6 (11%) patients. Electrocardiographic evidence of myocardial ischemia both et rest and anginal pain was seen in 46 (80%) patients. Electrocardiographic recording was within normal limits in 11 (20%) patients at rest. Clinical and ECG improvement was seen in 38 (66%) patients. Exercise tests in all of these patients were positive at low load work--mean 50 W. The obtained results suggest that patients with left coronary stenosis constitute heterogenous group. Therefore, prediction of the left main stenosis on the clinical ground alone is impossible. Exercise tests producing positive results at low load indicate with high probability critical multivessel lesions and/or left main stenosis in such patients.