In Leeds in hospital populations of patients with angina the maximal ST/HR slope was found to be a reliable index of
myocardial ischemia as assessed by coronary angiography. Subsequent studies in Leeds and elsewhere in populations of patients with cardiac enlargement or following
myocardial infarction have shown that the slope is affected by myocardial
scarring, ventricular enlargement and
aneurysm. These findings implied that the slope had features in common with other usual exercise tests; studies in Leeds and elsewhere, however, have shown a superior diagnostic reliability using the maximal ST/HR slope in patients with angina. The present report involves the use of the slope in asymptomatic populations. Trials are being undertaken in two factory populations, which respectively comprised all volunteers or asymptomatic men over the age of 30 who were randomly chosen by computer. Subjects with slope values indicating, according to previous experience,
myocardial ischemia equivalent to
coronary heart disease were referred for cardiological investigations which included angiocardiography; blind comparisons were performed between results of investigations and the slope. So far 1194 subjects have been examined. In 68 subjects the maximal ST/HR slope indicated
myocardial ischemia, and in 24 of these cardiological investigations were completed. In nine of the 24 subjects the slope corresponded to the number of significantly narrowed coronary arteries (greater than 75% reduction in
luminal diameter); in 12 of the remaining 15 subjects who had no coronary narrowing, there were cardiac lesions which included cardiac enlargement,
aortic valve disease,
myocarditis,
pericarditis,
myocardial bridging and conduction defects.(ABSTRACT TRUNCATED AT 250 WORDS)