Urumov G, Kostov E, Malamov E, Savova B
Vutr Boles. 1988;27(6):83-8.
200 patients (181 men and 19 women) with stable stenocardia were examined by the exercise tolerance test. The patients were loaded by the step by step method on veloergometer or threadmill up to 80% of the maximal pulse rate. 126 of the tests were evaluated as positive. False positive were 10 tests and 19 tests were false negative. The coefficient of sensitivity (independently of the limiting factor) was 82.2%, the specificity was 80%, the prognostic value of the positive test was 91.6%, of the negative test--68.3%. The sensitivity coefficient was: in the patients with one affected arterial branch--81.3%; in the patients with two affected arterial branches--80.4%, in the patients with three affected arterial branches--92.5% and in the patients with affection of the main arterial stem--87.5%. The patients were classified into three groups according to the expression of the limiting factors: I group with limiting factor pain (98 patients) with sensitivity coefficient 74.3%, specificity--77.8%, prognostic value of the positive test--89.1% and of the negative test--55.5%. II group with limiting factor ST-depression (83 patients) with sensitivity coefficient 71.3%, specificity--91.7%, prognostic value of the positive test--95% and of the negative test--61.1%. III group with limiting factors both pain and ST-depression with sensitivity coefficient 45.4%, specificity--91.7%, prognostic value of the positive test--95% and of the negative test--61.1%. The main conclusion from the study is that the limiting factor ST-depression as a basic objective sign of myocardial ischemia has high enough specificity and prognostic value and should be considered as a limiting factor with greatest informatory value.