ST segment elevation in lead aVR during exercise testing is associated with LAD stenosis

Area of Science:

• Cardiology
• Diagnostic Imaging
• Exercise Physiology

Background:

• Chest pain evaluation is crucial for diagnosing coronary artery disease.
• Exercise stress testing with electrocardiography (ECG) is a common diagnostic tool.
• Myocardial perfusion imaging (MPI) provides functional information about blood flow to the heart muscle.

Purpose of the Study:

• To assess the diagnostic value of ST elevation (STE) in lead aVR during stress testing.
• To correlate STE in aVR with ischemic territories identified by technetium-99m sestamibi scanning and coronary angiography.
• To compare the diagnostic utility of STE in aVR with ST depression (STD) in predicting inducible abnormalities and ischemic regions.

Main Methods:

• A prospective study of consecutive patients undergoing exercise treadmill testing prior to technetium-99m sestamibi MPI.
• Peak exercise ECGs were analyzed for ST elevation in lead aVR (>=0.05 mV).
• Correlations were made between ECG findings, MPI results, and coronary angiographic data.

Main Results:

• ST elevation in lead aVR occurred in 25% of patients and was associated with a higher rate of reversible defects on MPI.
• Patients with STE in aVR were more likely to have defects indicating a left anterior descending artery (LAD) culprit lesion.
• While STE in aVR was not an independent predictor of overall inducible abnormalities when adjusted for STD, it was a predictor of anterior wall defects.

Conclusions:

• ST elevation in lead aVR during exercise stress testing is not superior to ST depression alone for diagnosing inducible abnormalities.
• Unlike ST depression, STE in aVR may specifically indicate an anterior wall defect, aiding in the localization of myocardial ischemia.
• The findings suggest STE in aVR can be a valuable localized marker of ischemia in the anterior wall territory.