Coarctation of the aorta

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Aortic coarctation
Classification and external resources
ICD-10 Q25.1
ICD-9 747.10
OMIM 120000
DiseasesDB 2876
eMedicine med/154
MeSH D001017
File:Coarctation.png
Sketch showing heart with coarctation of the aorta. A: Coarctation (narrowing) of the aorta. 1:Inferior vena cava, 2:Right pulmonary veins, 3: Right pulmonary artery, 4:Superior vena cava, 5:Left pulmonary artery, 6:Left pulmonary veins, 7:Right ventricle, 8:Left ventricle, 9:Pulmonary artery, 10:Aorta
File:Coarctation and PDA.png
Schematic drawing of alternative locations of a coarctation of the aorta, relative to the ductus arteriosus. A: Ductal coarctation, B: Preductal coarctation, C: Postductal coarctation. 1: Aorta ascendens, 2: Arteria pulmonalis, 3: Ductus arteriosus, 4: Aorta descendens, 5: Truncus brachiocephalicus, 6: Arteria carotis communis sinistra, 7: Arteria subclavia sinistra

Coarctation of the aorta, or aortic coarctation, is a congenital condition whereby the aorta narrows in the area where the ductus arteriosus (ligamentum arteriosum after regression) inserts.

Types

There are three types:[1]

  1. Preductal coarctation: The narrowing is proximal to the ductus arteriosus. If severe, blood flow to the aorta distal to the narrowing (supplying lower body) is dependent on a patent ductus arteriosus, and hence its closure can be life-threatening. Preductal coarctation results when an intracardiac anomaly during fetal life decreases blood flow through the left side of the heart, leading to hypoplastic development of the aorta. This is the type seen in approximately 5% of infants with Turner Syndrome.[2][3]
  2. Ductal coarctation: The narrowing occurs at the insertion of the ductus arteriosus. This kind usually appears when the ductus arteriosus closes.
  3. Postductal coarctation: The narrowing is distal to the insertion of the ductus arteriosus. Even with an open ductus arteriosus blood flow to the lower body can be impaired. This type is most common in adults. It is associated with notching of the ribs (because of collateral circulation), hypertension in the upper extremities, and weak pulses in the lower extremities. Postductal coarctation is most likely the result of the extension of a muscular artery (ductus arteriosus) into an elastic artery (aorta) during fetal life, where the contraction and fibrosis of the ductus arteriosus upon birth subsequently narrows the aortic lumen.[4]

Signs and symptoms

Arterial hypertension in the right arm with normal to low blood pressure in the lower extremities is classic. Poor peripheral pulses and a weak femoral artery pulse may be found in severe cases.

If the coarctation is situated before the left subclavian artery, asynchronous radial pulses will be detected in the right and left arms. A radial-femoral delay between the right arm and the femoral artery would be apparent, whilst no such delay would occur under left arm radial-femoral palpation.

A coarctation occurring after the left subclavian artery will produce synchronous radial pulses, but radial-femoral delay will be present under palpation in either arm.

Imaging and diagnosis

With imaging, resorption of the lower part of the ribs may be seen, due to increased blood flow over the neurovascular bundle that runs there. Post-stenotic dilation of the aorta results in a classic 'figure 3 sign' on x-ray. The characteristic bulging of the sign is caused by dilatation of the aorta due to an indrawing of the aortic wall at the site of cervical rib obstruction, with consequent post-stenotic dilation. This physiology results in the '3' image for which the sign is named.[5][6][7] When the esophagus is filled with barium, a reverse 3 or E sign is often seen and represents a mirror image of the areas of prestenotic and poststenotic dilatation.[8]

Coarctation of the aorta can be accurately diagnosed with magnetic resonance angiography. In teenagers and adults echocardiograms may not be conclusive. In adults with untreated coarctation blood often reaches the lower body through collaterals, e.g. internal thoracic arteries via. the subclavian arteries. Those can be seen on MR, CT or angiography. An untreated coarctation may also result in hypertrophy of the left ventricle.

A case of coarctation of the aorta was published in the New England Journal of Medicine in 2007 employing chest radiography and magnetic resonance images.[9]

A case of long-standing misdiagnosed coarctation of the aorta in an adult was described in the New York Times Magazine.[10]

Therapy

Therapy is conservative if asymptomatic, but may require surgical resection of the narrow segment if there is arterial hypertension. The first operations to treat coarctation were carried out by Clarence Crafoord in Sweden in 1944.[11] In some cases angioplasty can be performed to dilate the narrowed artery. If the coarctation is left untreated, arterial hypertension may become permanent due to irreversible changes in some organs (such as the kidney)[citation needed].

For fetuses at high risk for developing coarctation, a novel experimental treatment approach is being investigated, wherein the mother inhales 45% oxygen three times a day (3 x 3–4 hours) beyond 34 weeks of gestation. The oxygen is transferred via the placenta to the fetus and results in dilatation of the fetal lung vessels. As a consequence, the flow of blood through the fetal circulatory system increases, including that through the underdeveloped arch. In suitable fetuses, marked increases in aortic arch dimensions have been observed over treatment periods of about two to three weeks[12]

References

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External links

Great arteries/
other arteries
Great veins
Arteriovenous malformation

ar:تضيق الأبهر de:Aortenisthmusstenose es:Coartación aórtica fa:کوآرکتاسیون آئورت fr:Coarctation de l'aorte it:Coartazione dell'aorta ja:大動脈縮窄 no:Koarktasjon av aorta nn:Koarktasjon pl:Koarktacja aorty pt:Coarctação da aorta ru:Коарктация аорты sr:Коарктација аорте

uk:Коарктація аорти
  1. ↑ Valdes-Cruz LM, Cayre RO: Echocardiographic diagnosis of congenital heart disease. Philadelphia, 1998.
  2. ↑ Cotran, R., V. Kumar, and N. Fausto (2005). Robbins Pathologic Basis of Disease, 7th Ed. W.B. Saunders. ISBN 0-8089-2302-1. 
  3. ↑ Volkl TM, Degenhardt K, Koch A, Simm D, Dorr HG, Singer H (2005). "Cardiovascular anomalies in children and young adults with Ullrich-Turner syndrome the Erlangen experience". Clin Cardiol. 28 (2): 88–92. PMID 15757080. 
  4. ↑ http://emedicine.medscape.com/article/903965-overview
  5. ↑ Sabatine, Marc (February 15, 2000). Pocket Medicine. Lippincott Williams & Wilkins. p. 256 pages. ISBN 0781716497. 
  6. ↑ Blecha, Matthew J. (August 30, 2005). "General Surgery ABSITE and Board Review (Pearls of Wisdom)". McGraw-Hill. ISBN 978-0071464314. 
  7. ↑ Brady Pregerson (October 1, 2006). "Quick Essentials: Emergency Medicine, 2nd Edition". ED Insight Books. ISBN 0976155273. 
  8. ↑ Singh, Vibhuti. Aorta, Coarctation. E-medicine. 
  9. ↑ Quiros-Lopez R, Garcia-Alegria J (2007). "A medical mystery -- high blood pressure". N Engl J Med. 356 (25): 2630. doi:10.1056/NEJMicm061308. PMID 17582073. 
  10. ↑ Sanders, L."Feeling the Pressure", "The New York Times", 3/18/2007.
  11. ↑ Radegran, Kjell (2003), "The early history of cardiac surgery in Stockholm", Journal of Cardiac Surgery, 18 (6): 564–572, doi:10.1046/j.0886-0440.2003.02071.x, ISSN 0886-0440, PMID 14992112, retrieved 2009-03-10 
  12. ↑ Kohl T, Tchatcheva K, Stressig R, Geipel A, Heitzer S, Gembruch U. Maternal hyperoxygenation in late gestation promotes rapid increase of cardiac dimensions in fetuses with hypoplastic left hearts with intrinsically normal or slightly abnormal aortic and mitral valves. Ultraschall in Med 2008;29: 92 [www.uniklinik-bonn.de/dzft]
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