Heart Attacks and Heart Disease More than a million Americans
have heart attacks each year. A heart attack, or myocardial
infarction (MI), is permanent damage to the heart muscle. "Myo"
means muscle, "cardial" refers to the heart, and "infarction"
means death of tissue due to lack of blood supply. What Happens
During a Heart Attack? The heart muscle requires a constant
supply of oxygen-rich blood to nourish it. The coronary arteries
provide the heart with this critical blood supply. If you have
coronary artery disease, those arteries become narrow and blood
cannot flow as well as they should. Fatty matter, calcium,
proteins, and inflammatory cells build up within the arteries to
form plaques of different sizes. The plaque deposits are hard on
the outside and soft and mushy on the inside. When the plaque is
hard, the outer shell cracks (plaque rupture), platelets (disc-
shaped particles in the blood that aid clotting) come to the
area, and blood clots form around the plaque. If a blood clot
totally blocks the a