Augmented leads (aVR, aVF, and aVL) were developed to derive more localized information looking at the right, lower, and left part of the heart respectively. Specifically, lead aVR obtains information from the right upper side of the heart. It also gives reciprocal information on the left lateral side of the heart, which is already covered by leads aVL, I, II, V5, and V6. This is the main reason lead aVR has become forgotten.
Wellen’s Syndrome was first described in 1982 in which 75% of patients with t wave inversions in V2-V4 went on to have an acute myocardial infarction (MI). This was again repeated in 1989, and showed that all patients with this morphology had >50% LAD stenosis. The incidence in the United States is about 10-15%.
You are handed an EKG for a 50 yo man with moderate chest pain for 2 hours now and no associated symptoms typical for ACS, PE, aortic dissection, or any other red flags of chest pain. He has no prior EKG’s on file.
- Is this early repolarization or ST elevation MI?
- Should I activate the cardiac catheterization lab?
Undifferentiated tachycardias, especially when the rate is extremely fast, make it difficult to see anything other than the QRS complexes! Is there a P or flutter wave?
What lead is the most overlooked on the EKG?
Lead aVR can provide some unique insight into 5 different conditions:
- Acute MI
- Tricyclic antidepressant (TCA) and TCA-like overdose
- AVRT in narrow complex tachycardias
- Differentiating VT from SVT with aberrancy in wide complex tachycardias by using the Vereckei criteria (possibly better than Brugada criteria)