Definition
What is a myocardial infarction?
A myocardial infarction is the medical name for a heart attack: an area of the myocardium, the heart muscle, dies because the coronary artery feeding it has become blocked. Most cases come from coronary artery disease. Over years, fatty plaques build up inside the artery wall, a process called atherosclerosis; when a plaque cracks, platelets gather and a clot forms that shuts off the flow. Less often, a sudden spasm of the artery is to blame.
Heart muscle without oxygen starts to die within minutes, and the damage spreads the longer the vessel stays closed. The classic symptom is pressure or pain in the center of the chest lasting more than a few minutes, often spreading to an arm, the jaw or back, with breathlessness, sweating and nausea. Women, older people and those with diabetes more often have vague or unusual symptoms. It differs from cardiac arrest, in which the heart stops pumping altogether, though it can trigger one.
Doctors confirm it with an electrocardiogram (ECG) and blood tests for troponin, a protein that leaks from injured heart cells. Treatment aims to reopen the artery fast, by angioplasty with a stent or with clot-dissolving drugs, followed by medicines such as aspirin, statins and beta blockers. The dead muscle heals as a scar, which can lead to heart failure.
Word parts
Where does the term “myocardial infarction” come from?
- myo-
- muscleGreek mys
- cardi-
- heartGreek kardia
- infarct-
- stuffed, pluggedLatin infarcire, to stuff into
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Terms that go with it
- InfarctionInfarction is the death of an area of tissue, called an infarct, caused by a sudden loss of its blood supply, as in a heart attack or a stroke.
- AtherosclerosisAtherosclerosis is a disease in which fatty plaque builds up inside artery walls, stiffening and narrowing the arteries and reducing blood flow.
- IschemiaIschemia is a shortage of blood supply to an organ or tissue, usually from a narrowed or blocked artery, that starves its cells of oxygen and nutrients.
- ThrombosisThrombosis is the formation of a blood clot, called a thrombus, inside a blood vessel or the heart, where it can narrow or block the flow of blood.
- HeartThe heart is the hollow, muscular organ in the chest whose four chambers pump blood through the lungs and then around the rest of the body.
- Heart failureHeart failure is a long-term condition in which the heart fails to pump as much blood as the body needs, even though it has not stopped beating.
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