Infarction

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Not to be confused with Infraction.
Micrograph of a pulmonary infarct (right of image) beside relatively normal lung (left of image). H&E stain.

In medicine, infarction is tissue death (necrosis) caused by a local lack of oxygen, due to an obstruction of the tissue's blood supply.[1] The resulting lesion is referred to as an infarct[2][3] (from the Latin infarctus, "stuffed into").[4]

Myocardial Infarction is the partial death of heart tissue commonly known as heart attack.

Causes[edit]

The supplying artery can be blocked by an obstruction (e.g., an arterial embolus, thrombus, or atherosclerotic plaque), may be mechanically compressed (e.g., tumor, volvulus, or hernia), ruptured by trauma (e.g., atherosclerosis or vasculitides), or vasoconstricted (e.g., cocaine vasoconstriction leading to myocardial infarction).

Infarction could be caused by damaged cholesterol plaque

Hypertension and atherosclerosis are risk factors for both atherosclerotic plaques and thromboembolism. In atherosclerotic formations, a plaque develops under a fibrous cap. When the fibrous cap is degraded by metalloproteinases released from macrophages or by intravascular shear force from blood flow, subendothelial thrombogenic material (extracellular matrix) is exposed to circulating platelets and thrombus formation occurs on the vessel wall occluding blood flow. Occasionally, the plaque may rupture and form an embolus which travels with the blood-flow downstream to where the vessel narrows and eventually clogs the vessel lumen.

Infarctions can also involve mechanical blockage of the blood supply, such as when part of the gut or testicles herniates or becomes involved in a volvulus.

Classification[edit]

Infarction of the lung due to a pulmonary embolism

By histopathology[edit]

Infarctions are divided into 2 types according to the amount of blood present:

A blood clot could be a broken thrombosis that got clotted to the blood vessel wall.
Micrograph of testis showing hemorrhagic infarction.H&E stain.

By localization[edit]

  • Brain: Cerebral infarction is the ischemic kind of stroke due to a disturbance in the blood vessels supplying blood to the brain. It can be atherothrombotic or embolic.[7] Stroke caused by cerebral infarction should be distinguished from two other kinds of stroke: cerebral hemorrhage and subarachnoid hemorrhage. Cerebral infarctions vary in their severity with one third of the cases resulting in death.
Ultrasound of segmental testicular infarction. Infarct area shown as hypoechoic and avascular upper segment of R testis.
  • Eye: an infarction can occur to the central retinal artery which supplies the retina causing sudden visual loss.

Associated diseases[edit]

Diseases commonly associated with infarctions include:

References[edit]

  1. ^ "Definition of Infarction". MedicineNet. WebMD. April 27, 2011. Retrieved August 19, 2011. 
  2. ^ "infarct". TheFreeDictionary.com.  Citing:
    • The American Heritage Dictionary of the English Language, Fourth Edition. Updated in 2009.
    • The American Heritage Science Dictionary 2005 by Houghton Mifflin Company.
  3. ^ infract. CollinsDictionary.com. Collins English Dictionary - Complete & Unabridged 11th Edition. Retrieved November 22, 2012.
  4. ^ http://www.etymonline.com/index.php?term=infarct&allowed_in_frame=0
  5. ^ Sekido, Nobuaki; Mukaida, Naofumi; Harada, Akihisa; Nakanishi, Isao; Watanabe, Yoh; Matsushima, Kouji (1993). "Prevention of lung reperfusion injury in rabbits by a monoclonal antibody against interleukin-8". Nature 365 (6447): 654–7. doi:10.1038/365654a0. PMID 8413628. 
  6. ^ Sands, Howard; Tuma, Ronald F (1999). "LEX 032: a novel recombinant human protein for the treatment of ischaemic reperfusion injury". Expert Opinion on Investigational Drugs 8 (11): 1907–1916. doi:10.1517/13543784.8.11.1907. PMID 11139833. 
  7. ^ Ropper, Allan H.; Adams, Raymond Delacy; Brown, Robert F.; Victor, Maurice (2005). Adams and Victor's principles of neurology. New York: McGraw-Hill Medical Pub. Division. pp. 686–704. ISBN 0-07-141620-X. 
  8. ^ Nores, M; Phillips, EH; Morgenstern, L; Hiatt, JR (1998). "The clinical spectrum of splenic infarction". The American surgeon 64 (2): 182–8. PMID 9486895. 
  9. ^ a b Grigoriadis, E; Fam, AG; Starok, M; Ang, LC (2000). "Skeletal muscle infarction in diabetes mellitus". The Journal of rheumatology 27 (4): 1063–8. PMID 10782838. 
  10. ^ Digiovanni, CW; Patel, A; Calfee, R; Nickisch, F (2007). "Osteonecrosis in the foot". The Journal of the American Academy of Orthopaedic Surgeons 15 (4): 208–17. PMID 17426292. 

External links[edit]

Media related to Infarction at Wikimedia Commons The dictionary definition of infarction at Wiktionary