Related Experiment Videos
Diagnostic value of the maximal ST segment/heart rate slope in asymptomatic factory populations
Insights
The maximal ST/HR slope effectively identifies myocardial ischemia in asymptomatic individuals. This exercise test shows promise for early detection of coronary heart disease and other cardiac conditions.
Area of Science:
- Cardiology
- Exercise Physiology
Background:
- The maximal ST/HR slope is a validated index for myocardial ischemia in symptomatic patients.
- Previous studies indicated its reliability in patients with cardiac enlargement or post-myocardial infarction.
Purpose of the Study:
- To evaluate the diagnostic utility of the maximal ST/HR slope in asymptomatic populations.
- To assess its effectiveness in identifying individuals with potential coronary heart disease.
Main Methods:
- A study involving 1194 asymptomatic factory workers aged over 30.
- Subjects with indicative maximal ST/HR slope values underwent cardiological investigations, including angiocardiography.
- Blind comparisons were made between slope results and diagnostic findings.
Main Results:
- The maximal ST/HR slope indicated myocardial ischemia in 68 subjects.
- Of 24 fully investigated subjects, 9 showed significant coronary artery narrowing.
- The remaining 15 subjects without coronary narrowing had other cardiac lesions, such as cardiac enlargement or valve disease.
Conclusions:
- The maximal ST/HR slope demonstrates potential for detecting myocardial ischemia in asymptomatic individuals.
- It may serve as a valuable screening tool for identifying subjects needing further cardiac investigation.
Abstract:
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)