The heart, which provides the whole body's need for blood, also needs a good blood supply to function properly. The veins that supply blood to the heart are coronary arteries, and when these become blocked, a heart attack occurs. Obstruction often begins with the accumulation of fat, cholesterol, and other substances that form a plaque in the arteries that feed the heart. In some cases, these plaques may be ruptured and a clot may be added to the plaque that completely blocks blood flow. In this case, the nourishment of the heart muscle area supplied by the occluded coronary artery is disrupted and some or most of the heart muscle may be damaged depending on the occlusion time.Devamı..