The acute coronary syndrome is a term used to describe a range of conditions associated with sudden, reduced blood flow to the heart. One such condition is a heart attack (myocardial infarction) — when cell death results in damaged or destroyed heart tissue. Even when acute coronary syndrome causes no cell death, the reduced blood flow changes how your heart works and is a sign of a high risk of a heart attack. The acute coronary syndrome often causes severe chest pain or discomfort. It is a medical emergency that requires prompt diagnosis and care. The goals of treatment include improving blood flow, treating complications, and preventing future problems.