The medical term for heart attack is myocardial infarction. A heart attack occurs when the blood supply to part of the heart muscle itself -- the myocardium-- is severely reduced or stopped. This occurs when one or more of the arteries that supply blood to the heart muscle (coronary arteries) is blocked by an obstruction. The blockage is sometimes from the buildup of plaque (deposits of fat-like substances) or can be caused by a blood clot lodged in a coronary artery. A myocardial infarction is the damaging or death of an area of the heart muscle resulting from a reduced blood supply to that area.
If the blood supply is cut off severely or for a long time, muscle cells suffer irreversible injury and die. Disability or death can result, depending on how much heart muscle is damaged.
Sometimes, a coronary artery temporarily contracts or goes into spasm. When this happens the artery narrows and blood flow to part of the heart muscle decreases or even stops. What causes a spasm is unclear. But it can occur in normal-appearing blood vessels as well as vessels partly blocked by atherosclerosis. If a spasm is severe, a heart attack may result.
The following are some symptoms:
Not all of these signs occur in every attack. Sometimes they go away and return. If some occur, get help fast.
The actual diagnosis of a heart attack must be made by a doctor who has studied the results of several tests. The doctor will: