Acute coronary syndrome (ACS) is the name given to several syndromes which are are caused by the sudden formation of blood clots (thrombosis) within a coronary artery. These blood clots are generally caused by rupture of a plaque in the wall of the artery. The clots produce partial or complete blockage of the artery, leading to ischemia (insufficient blood flow to the heart muscle). The type of ACS syndrome that occurs depends on the degree of blockage produced by the clot, and how long the clot persists. (Read more on how blood clots form within arteries.)
A person with ACS should be taken to the emergency room, where the doctor will try to determine if the person is having having either unstable angina, or one of two varieties of myocardial infarction - a ST segment elevation myocardial infarction, (or STEMI), or a non-ST segment elevation myocardial infarction, (or NSTEMI).
Immediate treatment for all patients with ACS is important, and the appropriate treatment depends on which type of ACS is occurring.
