The most forgotten Lead= aVR

The most neglected electrocardiographic lead may be the most important in some patients with ACS.Often relegated to the status of placeholder in the electrocardiogram, aVR may contain the critical data for the diagnosis of a number of conditions. A review in the American Journal of Emergency Medicine highlights pericarditis, left main coronary obstruction, orthodromic tachycardia and acute tricyclic antidepressant poisoning. From Medscape Emergency Medicine Viewpoints:
The takeaway point is simple: When patients with ACS, including non-STE ACS, demonstrate STE in lead aVR, the aggressiveness of early management must be
increased. These patients have more complex coronary lesions and will likely benefit from earlier invasive therapy.
Additional references:

ST elevation in aVR as a sign of left main coronary artery obstruction.

Review of electrocardiographic clues obtainable from aVR (JACC).


Classic paper on the electrocardiographic changes of pericarditis.

The electrocardiogram in non cardiac conditions..