This case and ECG was already posted here:
However, because of a new article, I want to post it again.
The patient presented with chest pain and had this ECG which is a very high risk situation. There was a severe ostial LAD thrombosis that was very close to the left main. He went for emergent bypass that evening and had a good outcome.
ST elevation in aVR is often thought to represent left main occlusion. However, it really just signifies widespread and diffuse subendocardial ischemia which could be due to left main or 3-vessel disease, or severe proximal LAD disease. Left Main occlusion generally causes rapid death; most who survive left main ACS have some flow and thus often have widespread ST depression.
There is an important recent article relevant to this:
Kosuge M, Ebina T, Hibi K, et al. An early and simple predictor of severe left main and/or three-vessel disease in patients with non-ST-segment elevation acute coronary syndrome. Am J Cardiol;107(4):495-500.
They show that if there is not at least 1 mm STE in aVR, then ACS is highly unlikely to be due to severe 3-Vessel disease or Left Main. Why is this important? Because if such severe CAD is present, the patient is likely to need CABG. If they need CABG, then the surgeon will usually be unhappy if the patient received clopidogrel.
So, here is a potential strategy: if there is no STE in aVR, then you can safely give clopidogrel to this NSTEMI patient. If there is at least 1 mm STE in aVR, then a GP IIbIIIa inhibitor should be given instead.