What is a heart attack (myocardial infarction)?

Every 25 seconds (average) an American suffers a coronary event, and every minute someone dies from heart/cardiovascular disease. http://circ.ahajournals.org/content/123/4/e18.full

What is a heart attack (myocardial infarction)?  The heart muscle needs oxygen just like the rest of our muscles.  Did you know that your heart which pumps blood throughout your body constantly needs a blood supply to the heart itself?  This blood supply (coronary arteries) provides the heart muscle with oxygenated blood.  If the coronary arteries become clogged by either plaque (from atherosclerosis or hardening of the arteries) or a blood clot, then the blood supply cannot reach all areas of the heart.  The heart muscle can be damaged and die from lack of oxygen.  That’s a heart attack or myocardial infarction.  (Myocardium is the medical term for heart muscle.  Infarction means an area of tissue death due to lack of oxygen.)  

One major contributing factor to a heart attack (and cardiovascular disease) involves atherosclerosis.  Atherosclerosis means a layer of plaque (excess cholesterol and other substances) builds up inside the arteries and decreases the inside diameter of the artery, and can partially block the blood supply.  In some cases, this decreased artery size can cause sluggish blood flow and clot formation inside the artery.