The importance of lead AVR

The most neglected electrocardiographic lead may be the most important in some patients with ACS. 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.

Background here.