Related Experiment Videos
Significance of changes in R wave amplitude during treadmill stress testing: angiographic correlation
Insights
Changes in R wave amplitude during exercise ECGs can indicate coronary artery disease. An increased R wave amplitude suggests severe dysfunction and coronary narrowing, while a decreased amplitude indicates normal function and healthy coronary arteries.
Area of Science:
- Cardiology
- Exercise Physiology
Background:
- Electrocardiography (ECG) is crucial for assessing cardiac function.
- R wave amplitude changes during exercise may correlate with coronary artery disease (CAD).
Purpose of the Study:
- To investigate the relationship between R wave amplitude changes during exercise and coronary artery disease severity.
Main Methods:
- Retrospective review of 89 patients' coronary angiograms and treadmill stress tests.
- Measurement of R wave amplitude changes between resting and immediate post-exercise periods.
Main Results:
- A decreased R wave amplitude post-exercise was strongly associated with normal coronary arteries (91% of patients with normal arteries).
- An increased R wave amplitude post-exercise was observed in 59% of patients with significant coronary artery disease (≥70% narrowing).
- Increased R wave amplitude correlated with more severe ventricular dysfunction and coronary narrowing.
Conclusions:
- Changes in R wave amplitude during exercise reflect ventricular function.
- Increased R wave amplitude indicates more severe cardiac dysfunction and significant coronary artery disease.
- Decreased R wave amplitude suggests normal or minimal cardiac dysfunction and is linked to normal coronary angiograms.
Abstract:
Coronary angiograms and treadmill stress tests were reviewed in 89 patients. Changes in R wave amplitude were measured in the control and immediate postexercise periods. Of 45 patients with normal coronary arteries, 41 (91 percent) had a decrease in R wave amplitude (P less than 0.01); 3 (7 percent) had an increase in amplitude, including 2 with abnormal left ventriculograms. The remaining patient (2 percent) had abnormal wall motion but no change in R wave amplitude. Among the 44 patients with significant coronary artery disease (70 percent or greater luminal narrowing in one or more vessels), R wave amplitude increased after exercise in 26 (59 percent) with more severe coronary artery disease. R wave amplitude decreased in 18 patients (41 percent) with normal or minimally abnormal resting ventriculograms and less severe coronary artery disease (P less than 0.01). Changes in R wave amplitude reflect ventricular function, an increase in R wave amplitude reflecting more severe dysfunction and severe coronary narrowing. A decreased R wave amplitude indicates normal or minimal dysfunction and is strongly associated with normal coronary angiograms.