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R wave amplitude changes during stress testing in ischemic patients with normal epicardial coronary arteries
Insights
Abnormal R wave amplitude changes during exercise stress tests indicate ischemia, even in patients with normal coronary angiograms. This electrocardiographic response may aid in diagnosing ischemia in such cases.
Area of Science:
- Cardiology
- Exercise Physiology
- Diagnostic Electrocardiography
Background:
- Coronary artery disease (CAD) diagnosis typically relies on coronary angiography.
- Identifying ischemia in patients with normal coronary angiograms presents a diagnostic challenge.
- Electrocardiographic (ECG) changes during stress testing are commonly used to detect myocardial ischemia.
Purpose of the Study:
- To investigate the diagnostic value of R wave amplitude changes during stress testing in patients with normal coronary angiograms.
- To compare the R wave amplitude response in patients with normal coronary arteries, those with confirmed CAD, and healthy controls.
Main Methods:
- Prospective study involving 12 patients with normal coronary angiograms and suspected ischemia.
- Comparison group included 10 patients with clinical and angiographic CAD and 10 normal controls.
- Exercise stress testing was performed, monitoring R wave amplitude changes in the ECG.
Main Results:
- An abnormal R wave amplitude response was observed in 83.3% of patients with normal coronary angiograms.
- A similar abnormal response rate (80%) was found in patients with confirmed CAD.
- Only 10% of the control group exhibited an abnormal R wave amplitude response.
Conclusions:
- The similar abnormal R wave amplitude response in patients with normal coronary arteries and those with CAD suggests a link to ischemia.
- R wave amplitude response during exercise stress testing may serve as a valuable non-invasive tool for diagnosing ischemia.
- This ECG marker could be particularly useful in patients with angiographically normal coronary arteries where ischemia is suspected.
Abstract:
R wave amplitude changes during stress testing were validated in 12 ischemic patients with normal coronary angiograms. The data were compared with findings obtained from 10 patients with clinical and angiographic evidence of coronary arterial disease and 10 normal controls. An abnormal R wave amplitude response occurred in 83.3% of the group with normal coronary angiography, in 80% of the group of patients with clinical and angiographic evidence of coronary arterial disease, and in only 10% of the control group. The similarity of R wave amplitude changes in the first two group suggests that these changes are related to ischemia. If so, then R wave amplitude response to exercise could be of value in the electrocardiographic diagnosis of ischemia in patients with angiographically normal coronary arteries.