Post-infarction heart. Illustration of a partly dissected human heart showing muscle damage caused by a myocardial infarction (heart attack). Heart attack is commonly due to a blood clot (thrombus) in the coronary artery. Here, the left ventricle is dissected open, exposing its inner chamber with thick muscular wall and valves. Extensive necrosis (cell death) of this muscle is seen in darkened patches and outer scarring. A clot in the left coronary artery blocked the oxygen supply to this region of the heart. Deposits of fat (yellow) along blood vessels suggest a diet high in choles- terol; fatty deposits within arteries encourage blood clotting, often with fatal consequences.