Challenging the STEMI paradigm: The case of total coronary occlusion in non-STEMI presentations

Prompt and accurate diagnosis of acute myocardial infarction (MI) in the emergency department (ED) is essential, as delayed treatment worsens patient outcomes. Current ST-elevation myocardial infarction (STEMI) criteria rely on ST-elevation (STE) in contiguous leads, yet emerging evidence suggests these criteria often miss acute coronary occlusion (ACO) in patients with atypical electrocardiographic (ECG) findings. We report the case of a 62-year-old male presenting to the ED with progressive chest pain radiating to left arm, accompanied by diaphoresis. His initial ECG showed isolated STE in lead II and ST depression in leads V4 and V5 but lacked the full STEMI criteria for diagnosing acute MI. During his ED stay, the patient suffered a sudden cardiac arrest from torsade de pointes and was successfully resuscitated. Urgent angiography revealed a 100 % occlusion in the obtuse marginal 1 (OM1) artery, along with significant stenosis in the left anterior descending (LAD) and right coronary arteries (RCA). The patient underwent successful OM1 stenting and was discharged in stable condition. This case emphasizes the limitations of the STEMI paradigm in identifying ACO in cases without classic STE, highlighting the importance of recognizing atypical ECG patterns by emergency physician to facilitate timely intervention. The emerging Occlusion MI (OMI) paradigm broadens diagnostic criteria to better identify high-risk patients, potentially improving early diagnosis, reducing missed ACO cases, and enhancing outcomes for those who do not meet traditional STEMI criteria.