Case Presentation: A 33 year old female with a history of antiphospholipid syndrome presented with exertional chest pain and ST-elevation in aVR with diffuse ST-depression. An emergent catheterization was performed which showed an isolated 99% stenosis in the left main coronary artery. The remaining coronary arteries were without any stenosis. Successful stent placement was performed, and the patient was discharged without complications.

Discussion: Previous guidelines suggested that ST-elevation with diffuse ST-depression should be treated as a STEMI-equivalent involving the left-main or proximal left anterior descending coronary artery. However recent data suggests that the majority of these cases may not involve that territory. Regardless, this ECG finding should still be concern for acute coronary syndrome with the need for urgent catheterization.