Differential Diagnosis for ST elevation in aVR

-ACS: Left main occlusion, proximal LAD occlusion, severe triple vessel disease

-Massive PE (think right axis, T wave inversions V1-V3)

-Thoracic aortic dissection

-Severe hypoperfusion

-Electrolyte abnormalities (hypokalemia: think QT prolongation, and hyperkalemia)

Say a patient is having chest pain with a story concerning for ACS. EKG shows ST segment elevation in aVR but no other leads. What do the guidelines say?

ACC/AHA, 2013: Multilead ST depression with coexistent ST elevation in lead aVR has been described in patients with left main or proximal left anterior descending artery occlusion. 

European Cardiology Society, 2017: STE in aVR in association with > 8 leads STD is consider STEMI equivalent

Fourth Universal Definition of MI, 2018: STE in aVR with repolarization patterns should be considered STEMI equivalent

Bottom line: ST elevation in aVR has a broad differential diagnosis, but in the right clinical setting with concern for ACS, there are guidelines to support this as a STEMI equivalent and should warrant a call to interventional cardiology. If pushback, advocate for your patient with evidence based medicine.