Left atrial appendage

Left atrial appendage
Heart seen from above. (Left auricula labeled at bottom left.)
Section of the heart showing the ventricular septum. (Left auricula labeled at upper right.)
Latin auricula sinistra
Gray's subject #138 533

The left atrial appendage (LAA)[1] (left auricular appendix,[2] auricula,[2] left auricle[3]) is a muscular pouch connected to the left atrium of the heart.

It has a distinct embryologic origin.[4]

Contents

Terminology

Although the LAA is sometimes called the left auricle[5], in older texts the term "left auricle" was often used differently to describe the structure now known as the left atrium.

Clinical significance

In atrial fibrillation, blood clots arise from the left atrial appendage in more than 90% of cases.[6] They may dislodge (forming emboli), which may lead to ischemic damage to the brain, kidneys, or other organs supplied by the systemic circulation.[7] Left atrial appendage occlusion is an experimental treatment to prevent stroke in atrial fibrillation.[8]

It can serve as an approach for mitral valve surgery.[9]

Function

Functions as a reservoir for the left atrium.

Radiology

The left atrial appendage can be seen on a standard posteroanterior x-ray, where the lower level of the left hilum becomes concave. [10]

Additional images

References

  1. ^ Akdeniz B, Badak O, Bariş N, et al. (March 2006). "Left atrial appendage-flow velocity predicts cardioversion success in atrial fibrillation" (– Scholar search). Tohoku J. Exp. Med. 208 (3): 243–50. doi:10.1620/tjem.208.243. PMID 16498232. http://joi.jlc.jst.go.jp/JST.JSTAGE/tjem/208.243?from=PubMed. 
  2. ^ a b "Gray's Anatomy". http://www.bartleby.com/107/pages/page533.html. Retrieved 2008-12-14. 
  3. ^ Netter, Frank H. (1989). "Section III: Thorax". Atlas of Human Anatomy (2nd ed.). East Hanover, NJ: Novartis. ISBN 978-0914168812. 
  4. ^ Donal E, Yamada H, Leclercq C, Herpin D (September 2005). "The left atrial appendage, a small, blind-ended structure: a review of its echocardiographic evaluation and its clinical role". Chest 128 (3): 1853–62. doi:10.1378/chest.128.3.1853. PMID 16162795. http://www.chestjournal.org/cgi/pmidlookup?view=long&pmid=16162795. 
  5. ^ Drake, Richard et al. (2010). Gray's Anatomy for Students. Churchill Livingstone. ISBN 9780443069529. 
  6. ^ Blackshear JL, Odell JA (February 1996). "Appendage obliteration to reduce stroke in cardiac surgical patients with atrial fibrillation". Ann. Thorac. Surg. 61 (2): 755–9. doi:10.1016/0003-4975(95)00887-X. PMID 8572814. 
  7. ^ Parekh A, Jaladi R, Sharma S, Van Decker WA, Ezekowitz MD (September 2006). "Images in cardiovascular medicine. The case of a disappearing left atrial appendage thrombus: direct visualization of left atrial thrombus migration, captured by echocardiography, in a patient with atrial fibrillation, resulting in a stroke". Circulation 114 (13): e513–4. doi:10.1161/CIRCULATIONAHA.106.617886. PMID 17000914. http://circ.ahajournals.org/cgi/pmidlookup?view=long&pmid=17000914. 
  8. ^ Stöllberger C, Schneider B, Finsterer J (December 2003). "Elimination of the left atrial appendage to prevent stroke or embolism? Anatomic, physiologic, and pathophysiologic considerations". Chest 124 (6): 2356–62. doi:10.1378/chest.124.6.2356. PMID 14665520. http://www.chestjournal.org/cgi/pmidlookup?view=long&pmid=14665520. 
  9. ^ Guhathakurta S, Kurian VM, Manmohan, Cherian KM (2004). "Mitral valve reoperation through the left atrial appendage in a patient with mesocardia". Tex Heart Inst J 31 (3): 316–8. PMC 521780. PMID 15562857. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=521780. 
  10. ^ Chest X-Ray Made Easy. Churchill Livingstone. 2002. ISBN 0443070083. 

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained within it may be outdated.

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