What exactly is a heart attack? How does it happen?
Heart attack is another name for coronary thrombosis, or a blockage in the arteries that supply blood to the heart. Although the attack is sudden, the conditions that cause it have been building up for years beforehand. As we grow older, changes occur in the inner lining of the arteries and they tend to thicken. In addition, fatty material from the blood may be laid down inside the arteries, thus narrowing the channel. Parts of this material may flake off, contributing to blockage and roughening the arterial wall. The narrowed channel slows down the flow of blood and where the wall is roughened, a blood clot may form. The clot, called a thrombus, cuts off the blood supply to part of the heart, and the heart attack occurs. If the clot blocks a major artery, the attack is likely to be fatal, because without blood the heart will stop beating. If the blockage is less serious, however, blood may find its way around the blocked artery to reach the heart through other blood vessels.