Summary:Ergometer exercise electrocardiographic (EECG) data were surveyed in a series of 328 patients (277 men and 5 1 women) subjected to coronary arteriography. The sensitivity and specificity of EECG for coronary artery disease (CAD) were 84% and 54%, respectively. The predictive accuracy of a positive test for CAD was 95% in men and 81 % in women. The predictive accuracy of a negative test was 25% in men and 62% in women. When slowly ascending ST depression was considered insignificant, the sensitivity of EECG declined to 71 %, with an increase in specificity to 64%. CAD was present in 89% of the patients with slowly ascending ST depression and 65% of them had a multivessel disease. Seventy-two subjects had postexercise ST-segment elevation. The predictive value of this sign for CAD was 94%. Exercise-induced chest pain had quite a similar diagnostic significance as EECG. The prevalence of CAD in patients with a history of typical angina was 94% in both sexes. Atypical chest pain was associated with normal coronary arteriography in 59% of males and 100% of females.