STEMI

STEMI is the most clear-cut and dangerous kind of heart attack: a coronary artery is completely blocked, and the full thickness of the muscle it feeds is in jeopardy. It is the emergency where every minute genuinely counts.

Its name comes from the ECG. A total occlusion injures muscle right across the wall of the heart, producing a characteristic upward shift of the ST segment in the leads facing the affected region. That signature lets clinicians recognize a STEMI within minutes of the patient arriving — before troponin results are even available — and act immediately.

Because the artery is fully shut, the priority is to reopen it as fast as possible. The preferred treatment is primary percutaneous coronary intervention (an emergency angioplasty with a stent); where that cannot be delivered quickly, clot-dissolving thrombolysis is used. The shorter the total time from symptom onset to reopened artery, the more muscle is saved and the better the survival.

STEMI is distinguished from NSTEMI by this ST elevation and, usually, a more complete occlusion; the two follow different treatment pathways, with STEMI demanding the most urgent reperfusion.