The value of electrocardiographic R-wave changes in exercise testing: Preexercise versus postexercise measurements

Area of Science:

• Cardiology
• Diagnostic Imaging
• Exercise Physiology

Background:

• Electrocardiographic (EKG) exercise testing is crucial for diagnosing coronary artery disease (CAD).
• Discrepancies exist in the literature regarding the diagnostic value of R-wave amplitude changes during exercise testing.
• Understanding these discrepancies is vital for accurate CAD diagnosis.

Purpose of the Study:

• To evaluate the diagnostic utility of R-wave amplitude changes during exercise testing for CAD.
• To clarify the differing reported values of R-wave amplitude changes in CAD diagnosis.
• To determine the optimal timing for measuring R-wave amplitude changes for diagnostic accuracy.

Main Methods:

• Two patient groups (N=149 prospectively, N=156 retrospectively) underwent EKG treadmill testing and coronary arteriography.
• R-wave amplitude changes were measured from pre-exercise to immediately post-exercise (SRV(5)) and pre-exercise to peak exercise (URV(5)).
• Specificity and sensitivity of these measurements for diagnosing CAD were calculated.

Main Results:

• The specificity of SRV(5) was high (81% in Group I, 84% in Group II).
• The specificity of URV(5) was significantly lower (46% in Group I, 39% in Group II).
• Sensitivity of SRV(5) was moderate (38% in Group I, 42% in Group II).

Conclusions:

• R-wave amplitude changes measured immediately post-exercise (SRV(5)) demonstrate diagnostic value for CAD.
• Measuring R-wave amplitude changes at peak exercise (URV(5)) yields poor diagnostic specificity.
• SRV(5) is a potentially useful parameter in electrocardiographic exercise testing for CAD diagnosis.