Electrocardiographic Recognition of Unprotected Left Main ST-Segment Elevation Myocardial Infarction: Looking Beyond aVR.

ST-segment elevation in aVR has traditionally been used for electrocardiographic identification of left main coronary artery (LM) myocardial infarction. We present two ST-segment elevation myocardial infarction (STEMI) cases with acute total occlusion of the LM without aVR ST-segment elevation. This report reviews the different electrocardiographic discriminators suggestive of unprotected LM STEMI. (Level of Difficulty: Intermediate.).