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Use of the ambulatory ECG to diagnose coronary artery disease
Insights
Ambulatory ECG monitoring effectively detects coronary artery disease (CAD) and complements exercise tests, especially when exercise tests are inconclusive or not feasible for patients.
Area of Science:
- Cardiology
- Non-invasive diagnostic techniques
Background:
- Coronary artery disease (CAD) diagnosis relies on various methods.
- Exercise testing is common but can be limited by contraindications or equivocal results.
Purpose of the Study:
- To evaluate the diagnostic accuracy of ambulatory ECG monitoring for CAD.
- To compare ambulatory ECG with exercise testing and coronary angiography.
Main Methods:
- Forty-nine patients with suspected CAD underwent ambulatory ECG monitoring and treadmill exercise tests.
- Ambulatory ECG recordings were analyzed for ST segment deviations.
- Results were compared with exercise test outcomes and coronary angiography.
Main Results:
- Ambulatory ECG showed 76% sensitivity and 75% specificity for CAD detection.
- Exercise testing had 78% sensitivity and 63% specificity.
- Ambulatory ECG correctly classified 12/16 patients with equivocal or contraindicated exercise tests.
- ST segment deviations on ambulatory ECG were found in 93% of patients with significant CAD (multi-vessel disease).
Conclusions:
- Ambulatory ECG monitoring is an effective non-invasive tool for diagnosing CAD.
- It serves as a valuable complement to exercise testing, particularly for patients with limited exercise test utility.
- Ambulatory ECG demonstrates high diagnostic accuracy, especially in identifying multi-vessel coronary artery disease.
Abstract:
Forty-nine patients undergoing cardiac catheterization for suspected coronary artery disease (CAD) were monitored with a two-channel ambulatory ECG and were given maximal treadmill exercise tests when these were not contraindicated. The ambulatory ECG recordings were evaluated for the number of ST segment deviations after correction for positional changes, and the results were then compared with those of the exercise test and coronary angiography. Sensitivity and specificity of ambulatory ECG monitoring for ST segment deviations to detect CAD were 76% and 75% respectively while those of exercise testing were 78% and 63% respectively. Sixteen patients (33% of this series) had equivocal or contraindicated exercise tests and twelve of these patients were correctly classified as to the presence or absence of CAD by ambulatory ECG. ST segment deviations on ambulatory ECG were found in 93% of patients with three vessel, two vessel, or one vessel LAD disease, while exercise testing detected 74% of these patients. Ambulatory ECG is an effective non-invasive method to diagnose CAD and is complementary to excercise testing. It is of special value when the exercise test is equivocal or contraindicated.