Do the right precordial leads during exercise testing contribute to detection of coronary artery disease?

Background: It is still unknown whether or not the additional right precordial leads (RPL) during exercise testing contribute to detection of coronary artery disease (CAD). Hypothesis: The aim of this study was to evaluate the RPL during exercise testing for the detection of CAD. Methods: The study included 157 consecutive patients (116 men and 41 women, mean age 66 years) suspected of having CAD, who underwent conclusive treadmill exercise testing (heart rate reached at least 85% of the predicted maximum or positive electrocardiogram [ECG] changes were exhibited) and coronary angiography. During exercise testing, the ECG was recorded with the standard 12 leads and 4 RPL (V3R, V4R, V5R, V6R). Results: Of the 157 patients, 67 had CAD (> 75% stenosis in at least one major coronary artery), and 64 had positive ST changes in the standard ECG leads during exercise testing. Using the conventional 12-lead method, sensitivity and specificity were 76 and 86%, respectively. Only three patients exhibited positive changes in the RPL leads; all had > 0.1 mV ST elevation in one of the RPL leads with > 0.1 mV ST elevation in aVR. Two of these patients had significant right coronary artery lesions and the other had a lesion of the left anterior descending artery which perfused the inferior as well as the anteroseptal area. In the standard 12 leads, one of the patients with an abnormal RPL and a right coronary lesion was negative, while the other two patients were positive. Combining RPL with the conventional 12-lead method, sensitivity and specificity were 78 and 86%, respectively. Therefore, RPL did not improve the accuracy of the exercise ECG. Conclusion: The use of RPL during exercise testing may contribute to the detection of ischemia perfused by the right coronary artery; however, it does not improve the diagnostic accuracy of the exercise test.