What causes a heart attack?
The cause of a heart attack, silent or otherwise is almost always atherosclerosis, which is the progressive narrowing of the heart’s arteries from accumulations of cholesterol plaque. This plaque ruptures and a clot or thrombus forms at the site of injury. This plaque and clot completely obstruct the flow of blood to the heart muscle the coronary artery supplies.
Atherosclerosis Atherosclerosis is a gradual process by which plaques (collections) of cholesterol are deposited in the walls of arteries. Cholesterol plaques cause hardening of the arterial walls and narrowing of the inner channel (lumen) of the artery. Arteries that are narrowed by atherosclerosis cannot deliver enough blood to maintain normal function of the parts of the body they supply. For example, atherosclerosis of the arteries in the legs causes reduced blood flow to the legs. Reduced blood flow to the legs can lead to pain in the legs while walking or exercising, leg ulcers, or a delay in the healing of wounds to the legs. Atherosclerosis of the arteries that furnish blood to the brain can lead to vascular dementia (mental deterioration due to gradual death of brain tissue over many years) or stroke (sudden death of brain tissue). In many people, atherosclerosis can remain silent (causing no symptoms or health problems) for years or decades. Atherosclerosis can begin as early
A heart attack is also called a myocardial infarction (MI) or an acute myocardial infarction (AMI). Many heart attacks are caused by a complete blockage of a vessel in your heart, called a coronary artery. A blocked coronary artery prevents oxygen-rich blood and nutrients from reaching a section of the heart. If blood cannot reach the heart muscle, it will die. By getting medical treatment quickly, you can reduce this damage, but once a section of heart muscle dies, the damage lasts forever. Heart attacks may be caused by • A fatty buildup called plaque, which severely narrows or blocks a coronary artery. The blockage shuts off all blood flow to the section of heart muscle fed by the artery. • A blood clot, which can block an artery already narrowed by plaque. The blood clot may come from another part of the body, carried by blood flow through the narrowed artery. The blockage shuts off all blood flow to the section of heart muscle fed by the artery. • A clot that forms at the site of
