NSTEMI

NSTEMI is a real heart attack in which the artery is squeezed nearly shut rather than fully corked. Heart muscle dies — confirming an infarction — but the ECG does not show the dramatic ST elevation of its more severe cousin.

Typically a plaque has ruptured and a clot has formed, but the artery is only partially occluded, or it is fully blocked yet rescued by collateral vessels supplying the area from another direction. Either way, blood flow is critically reduced and some muscle is injured. The diagnosis rests on a rise in cardiac troponin together with symptoms or ECG changes such as ST depression or T-wave inversion.

Because the artery is not completely shut, the immediate reperfusion clock is less frantic than in STEMI, and thrombolysis is generally not used. Management combines antiplatelet and anticoagulant drugs to stop the clot growing, anti-ischemic medication, and risk-based timing of coronary angiography — often within a day or two — to decide on stenting or bypass.

NSTEMI shares its plaque-rupture origin with STEMI and unstable angina; what separates it is troponin-confirmed muscle death without ST elevation, placing it between unstable angina and STEMI in severity.