Lead augmented vector right (aVR) is a useful measure in the diagnosis of ST-segment elevation acute myocardial infarction (STEMI), indicates a new analysis of data from the HERO-2 trial.

The negative of lead aVR (R for right arm) is at +30 degrees; the positive of lead aVR is actually at -150 degrees. Although memorizing the above picture is crucial to accurately determining axis ...