Limitations of the electrocardiographic response to exercise in predicting coronary-artery disease
Insights
Exercise electrocardiography has limited diagnostic value for coronary artery disease. False-negative results are common in patients with suspected disease, while false-positives occur in asymptomatic individuals.
Area of Science:
- Cardiology
- Diagnostic Imaging
- Preventive Medicine
Background:
- Exercise electrocardiography (ECG) is a common non-invasive tool for diagnosing coronary artery disease (CAD).
- Type II hyperlipoproteinemia is a risk factor for CAD.
- Previous myocardial infarction or angina necessitates careful evaluation of cardiac function.
Purpose of the Study:
- To evaluate the diagnostic usefulness of exercise electrocardiography in patients with Type II hyperlipoproteinemia.
- To compare exercise ECG results with coronary angiography findings.
- To assess the rates of false-negative and false-positive exercise ECG tests in different patient groups.
Main Methods:
- Retrospective analysis of 89 patients with Type II hyperlipoproteinemia.
- Patients were categorized into three groups based on clinical presentation and prior cardiac events.
- Comparison of exercise ECG results with coronary angiography findings.
Main Results:
- In patients with prior myocardial infarction or typical angina (Group A), 67% of those with significant stenosis (>=50%) had negative exercise tests.
- In patients with atypical angina (Group B), a low rate of positive exercise tests was observed among those with significant stenosis.
- In asymptomatic patients with a positive exercise ECG (Group C), a significant proportion had normal or non-obstructive coronary arteries.
Conclusions:
- Exercise electrocardiography demonstrates limited diagnostic utility for coronary artery disease, particularly in patients with suspected CAD.
- High rates of false-negative exercise ECG results were observed in patients with established or suspected coronary artery disease.
- False-positive exercise ECG results are common in asymptomatic individuals, leading to potential overdiagnosis.
Abstract:
The electrocardiographic response to exercise was compared with the results of coronary angiography in 89 patients with Type II hyperlipoproteinemia who had previous myocardial infarction or typical angina or both (43 patients)(Group A), "atypical angina" (16 patients)(Group B)or positive electrocardiographic response to exercise without other evidence of cardiac disease (30 patients)(Group C). Thirty-nine of 43 in Group A had greater than or equal to 50 per cent stenosis, and 26 (67%) of these 39 had negative exercise tests. In Group B, five of the 16 had greater than or equal to 50% stenosis, and three had positive exercise tests (one patient had a false-positive test). In Group C, eleven of 30(37%) had greater than or equal to 50% stenosis; however, nine (30%) had minor stenosis (less than or equal to 50%), and 10(33%) normal coronary arteries. The diagnostic usefulness of exercise electrocardiography is limited. False-negative responses are frequent in patients with clinically suspected coronary disease, and false-positive responses frequent in asymptomatic patients.
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