Left Main Coronary Artery Disease: The Forgotten Lead of Electrocardiogram Is Predictive.

An ST segment depression in eight or more leads along with ST segment elevation in lead aVR or V1, especially occurring during ischemic symptoms, has a very high predictive accuracy of left main or three-vessel disease, or tight proximal left anterior descending (LAD) coronary artery stenosis. We describe a classic case of a patient who presented with ST elevation in the lead aVR with diffuse ST segment depression during anginal symptoms and was found to have severe disease in the distal left main, ostial circumflex, and left anterior descending artery on an emergent coronary angiogram.