Heart is an organ is the size of the fist locate on the left side of the chest, From the chest it pumps blood to the body continuously till we die, it is organ it also require blood supply, so to supply blood to the heart it there are 3 blood vessel called arteries, that supply blood to the heart one of the right, one of the left, one of the front, when they are supplying the blood heart, can work nicely, for some times various reasons blocks will happen these arteries in different locations because of cholesterol, fat, many other reasons.