To determine the diagnostic value of the electrocardiographic exercise testing (EET) in 551 patients with chest pain regarded as definite or probable stable angina pectoris (CAD), results of performed EET were compared with coronary angiography. All patients underwent exercise testing according to the Bruce protocol. The criterion for a positive exercise ST-segment response was > or = 1 mm of horizontal or down sloping depression 80 msec after J-point. The indications for cardiac catheterization in each patient were determined at the discretion of the attending physician. Clinically important coronary artery disease was defined as > 50 per cent narrowing of the diameter of at least one major vessel or > or = 50 per cent of the left main coronary artery.
Results: The sensitivity and specificity of EET for detection of CAD were for the entire group, in women and men respectively: 93%, 91%, 94% and 21%, 16%, 27%.
Conclusion: 1. Indications for EET should be based on prior probability of coronary artery disease. 2. Application of higher than conventional ST depression criteria (> or = 2 mm) lowers sensitivity but increases specificity of EET. 3. Variables determining false positive results are as follows: age, sex (female), low probability of CAD, ST-segment depression in leads: II, III, aVF and mitral valve prolapse. 4. Variables determining false negative results are as follows: high probability of CAD, sex (male) and one vessel disease.