What causes the blockage in a coronary artery?
The reason for the blockage is usually a buildup of plaque (deposits of fat-like substances) in the walls of the coronary arteries. The plaque buildup narrows the walls of the artery and can cause blood clots to occur. Plaque buildup is caused by a disease known as atherosclerosis (hardening of the arteries). An atherosclerotic plaque is made up of cells, cholesterol, and other fatty substances. The plaque develops in the wall of the coronary artery and over time becomes large enough to start narrowing the channel through which the blood travels. The pool of lipid (the fat) within the plaque is covered by a thin fibrous cap. This cap may split or fracture, exposing the blood to elements within the plaque that cause blood clot formation. This clotting process may be controlled by the body, which contains substances to dissolve clots, or may lead to complete blockage of the artery. When the artery is blocked acutely for more than a few minutes, cell death starts to occur. Coronary heart
