ST Elevation Myocardial Infarction Heart Attack

(STEMI)

Overview

An ST-segment elevation myocardial infarction (STEMI) is a serious heart attack in which a coronary artery (artery supplying blood to the heart) suddenly becomes completely blocked, and a part of the heart muscle cannot receive blood. “ST-segment elevation” refers to a pattern on an electrocardiogram (ECG/EKG).

A graphic showing the different types of electrocardiogram readings. It shows normal, "STEMI", and "NSTEMI" waves.

This type of heart attack requires immediate/emergent opening of the artery, which restores blood flow through the artery. This revascularization is achieved either with drugs like thrombolytics (clot busters), which are given intravenously, or mechanically with angioplasty, a treatment using thin, flexible tubes called catheters to open the closed artery.

These catheters are positioned in the opening of the coronary arteries, and contrast dye is injected into them to enable the interventional cardiologist to gather images of any blockage in the coronary arteries. Thin wires (guidewires) are advanced beyond the blockage, the clot is sucked out, and/or a small balloon is opened to push the blockage out of the way. A stent—a metal mesh tube—is often inserted simultaneously to prop the cleared artery open to allow blood to flow through.