A heart attack occurs when the flow of blood to the heart is blocked. The blockage is most often a buildup of fat, cholesterol and other substances, which form a plaque in the arteries that feed the heart (coronary arteries). Sometimes, a plaque can rupture and form a clot that blocks blood flow.
A heart attack (myocardial infarction or MI) is serious in which the supply of blood to the heart is suddenly blocked, usually by a blood clot.
A heart attack is a medical emergency.
A lack of blood to the heart may seriously damage the heart muscle and can be life threatening.
