Utility of lead V₄R in exercise testing for detection of coronary artery disease

Several reports have documented the frequent association of right ventricular infarction with inferior wall left ventricular infarction.^1-4 Because the right coronary artery always supplies the right ventricular wall as well as a variable part of the left ventricular wall, electrocardiographic leads sensitive to right ventricular ischemia might be expected to improve exercise test sensitivity in detecting significant narrowing of the right coronary artery. ST-segment elevation in right-sided precordial leads has been proven useful in diagnosing right ventricular infarction in patients with inferior wall left ventricular infarctions.^4,5 ST elevation of ≥1 mm in V₄R was found to be 100% sensitive and 87% specific in diagnosing occlusion of the right coronary artery proximal to the first right ventricular branch.⁴ V₄R has also been used in exercise testing to predict proximal stenosis of the right coronary artery.⁶ This study assesses the utility of V₄R in routine exercise testing to diagnose significant narrowing of any major coronary artery, particularly the right coronary artery.