Infarction

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.

Classification

Infarctions are divided into two types according the amount of hemorrhaging present:
* 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.
*Red infarctions (hemorrhagic infarcts), generally affecting the lungs. The occlusion consists more of red blood cells and fibrin strands.

Diseases

Diseases commonly associated with infarctions include:
* Myocardial infarction (heart attack)
* Pulmonary embolism ("lung attack")
* Cerebrovascular accident (stroke – 80% are due to infarction)
* Peripheral artery occlusive disease (the most severe form of which is gangrene)
* Antiphospholipid syndrome
* Sepsis
* Giant-cell arteritis (GCA)
* Hernia
* Volvulus