In
medicine, an 'infarction' is the process resulting in a
macroscopic area of
necrotic tissue in some organ caused by loss of adequate blood supply. Supplying
arteries may be blocked from within by some obstruction (e.g. a
blood clot or fatty
cholesterol deposit), or may be mechanically compressed or ruptured by trauma.
Infarction is commonly associated with
atherosclerosis, where an atherosclerotic plaque ruptures, a
thrombus forms on the surface
occluding the blood flow and occasionally forming an
embolus that occludes other blood vessels downstream. Infarction can also involve mechanical blockage of the blood supply, such as when part of the gut
herniates or
twists.
Infarctions are divided into two types according the amount of
hemorrhaging present:
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White infarctions (
anemic infarcts) affect solid organs such as the
heart,
spleen, and
kidneys. The occlusion is most often composed of
platelets, and the organ becomes white, or pale.
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Red infarctions (
hemorrhagic infarcts), generally affecting the
lungs. The occlusion consists more of
red blood cells and
fibrin strands.
Diseases commonly associated with infarctions include:
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Myocardial infarction (heart attack)
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Pulmonary embolism ("lung attack")
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Cerebrovascular accident (stroke – 80% are due to infarction)
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Peripheral arterial occlusive disease (the most severe form of which is
gangrene)
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Antiphospholipid syndrome
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Sepsis
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Giant-cell arteritis (GCA)
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Hernia
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Volvulus