Predictive Value of Exercise Stress Test-Induced ST-Segment Changes in Leads V1 and avR in Determining Angiographic Coronary Involvement

Background: The significance of electrocardiographic changes during exercise tolerance testing for distinguishing occluded artery is not well known. We tried to determine the role of ST elevation in leads aVR and V-1 during exercise in detecting stenosis of left main coronary artery and proximal left anterior descending artery. Methods: ST segment changes during exercise in 230 patients, who underwent diagnostic angiography, were documented. The association of ST elevation in lead aVR, V-1, leads aVR + V-1, and STE in leads aVR + V-1 with ST depression in other leads with pattern of coronary stenosis were investigated. Results: Left main and proximal left anterior artery stenosis were more common in patients with ST elevation in lead aVR (P < 0.001 for both). Similar association was found in the presence of ST elevation in lead V1. The presence of ST elevation >= 1 mm in lead aVR had a sensitivity of 100% and 94.3% for detecting left main and left anterior descending artery stenosis, respectively. The specificity was 33.5% and 26.6%, respectively. ST elevation in leads aVR + V-1 had a sensitivity of 74.4% and 65.9% and a specificity of 68.5% and 64.4% for detecting left main and left anterior descending arteries stenosis, respectively. Conclusion: ST elevation in lead aVR is highly sensitive for left main and proximal left anterior descending artery lesions. Using ST elevation in lead V-1 in addition to lead aVR as a positive finding increases the specificity with a further decrease in sensitivity.