ABSTRACT
KEY POINTS ■ Acute myocardial infarction (AMI) occurs when there are severe and prolonged reductions in
coronary blood flow and myocardial oxygen delivery usually associated with coronary artery thrombosis. Myocardial infarction (MI) begins on the inner wall of the heart and is confined there in the first 30 minutes to one to two hours. Referred to as non-Q wave MI (NQMI) or nonST segment elevation MI (NSTEMI), most of these infarcts are limited to the subendocardial region. With longer periods of severely reduced coronary blood flow, the infarct progresses vertically outward to become an ST elevation MI (STEMI) or Q wave MI that is often transmural in extent.
