[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Embryology](https://durgical.com/en/embryology/) › [Heart and vessels](https://durgical.com/en/embryology/#a-heart) › Coarctation of the aorta [Embryology](https://durgical.com/en/embryology/) · [Heart and vessels](https://durgical.com/en/embryology/#a-heart) # Coarctation of the aorta - Malformation A narrowing of the aorta near the ductus arteriosus means the arms get more pressure than the legs. Updated 2026-11-01 **See it in 3D:** [Aortic arch](https://durgical.com/en/anatomy/aortic-arch/) · [Thoracic aorta](https://durgical.com/en/anatomy/thoracic-aorta/) · [Ligamentum arteriosum](https://durgical.com/en/anatomy/ligamentum-arteriosum/) · [Subclavian artery](https://durgical.com/en/anatomy/right-subclavian-artery/) · [Left ventricle](https://durgical.com/en/anatomy/left-ventricle/) · [Aortic right coronary cusp](https://durgical.com/en/anatomy/right-coronary-leaflet/) · [Aortic left coronary cusp](https://durgical.com/en/anatomy/left-coronary-leaflet/) · [Aortic non-coronary cusp](https://durgical.com/en/anatomy/non-coronary-leaflet-of-aortic-valve/) ## Key points - Site: aorta next to the ductus arteriosus, beyond the left subclavian (left 4th arch and dorsal aorta segment). - Preductal: infant; the lower body is supplied through the ductus; crisis when it closes. - Postductal: arm hypertension, weak and delayed femoral pulses. - Intercostal collaterals: rib notching and the '3' sign on chest X-ray. - Associations: Turner syndrome (45,X), bicuspid aortic valve, cerebral aneurysms. - Acyanotic (except differential cyanosis in the preductal form). ## What it is Coarctation is a narrowing of the aorta, almost always next to the insertion of the ductus or ligamentum arteriosum, distal to the left subclavian. It can be preductal (the severe infant form, duct-dependent) or postductal (the form of older children and adults, with collateral circulation). It is acyanotic, typical of Turner syndrome and associated with a bicuspid aortic valve. ## Embryological cause - One theory: ductal smooth muscle extends into the aortic wall and narrows it as the ductus constricts at birth. - Another: an abnormality of the aortic tunica media followed by intimal proliferation. - Reduced flow through the fetal aorta (e.g. with left-sided obstruction) favors a hypoplastic isthmus. - The affected segment lies where the left 4th arch, the ductus (6th arch) and the dorsal aorta meet. ## Markers - Turner syndrome (45,X) - Bicuspid aortic valve ## How it presents - Infant: heart failure or shock as the ductus closes; absent femoral pulses. - Older child or adult: upper-limb hypertension, headache, leg claudication. - Pressure and pulse difference between arms and legs. - Interscapular systolic murmur; collateral murmurs. ## Diagnosis - Measure blood pressure and oximetry in the right arm and one leg. - Echocardiography; CT angiography or MRI define the anatomy. - Chest X-ray: rib notching (in older children) and the '3' sign. ## Memory aid Strong arms, weak legs: the aorta wears a tight belt just after it gives off the left arm's branch. ## Test yourself Think of the answer, then tap the question to see it. ## Where is coarctation of the aorta almost always located? Next to the insertion of the ductus or ligamentum arteriosum, distal to the origin of the left subclavian. ## Which chromosomal syndrome is associated with coarctation? Turner syndrome (45,X). ## Why does rib notching appear in postductal coarctation? Intercostal arteries enlarge as collaterals to feed the distal aorta and erode the lower edges of the ribs. ## Why does an infant with preductal coarctation worsen after a few days? Because the lower body depended on the ductus arteriosus, and it closes. [Add to my cards (4)](https://durgical.app/estudiar/?add=/en/embryology/coarctation-of-the-aorta/) ## See it in 3D The structures of Durgical's 3D anatomy where it is found. - [Aortic arch](https://durgical.com/en/anatomy/aortic-arch/) - [Thoracic aorta](https://durgical.com/en/anatomy/thoracic-aorta/) - [Ligamentum arteriosum](https://durgical.com/en/anatomy/ligamentum-arteriosum/) - [Subclavian artery](https://durgical.com/en/anatomy/right-subclavian-artery/) - [Left ventricle](https://durgical.com/en/anatomy/left-ventricle/) - [Aortic right coronary cusp](https://durgical.com/en/anatomy/right-coronary-leaflet/) - [Aortic left coronary cusp](https://durgical.com/en/anatomy/left-coronary-leaflet/) - [Aortic non-coronary cusp](https://durgical.com/en/anatomy/non-coronary-leaflet-of-aortic-valve/) ## Related - [Aortic arch arteries and their derivatives](https://durgical.com/en/embryology/aortic-arch-arteries-and-their-derivatives/) - [Patent ductus arteriosus](https://durgical.com/en/embryology/patent-ductus-arteriosus/) - [Hypoplastic left heart syndrome](https://durgical.com/en/embryology/hypoplastic-left-heart-syndrome/) - [Vascular rings and aberrant right subclavian artery](https://durgical.com/en/embryology/vascular-rings-and-aberrant-right-subclavian-artery/) ## Related conditions - [Coarctation of the aorta](https://durgical.com/en/conditions/coarctation-of-the-aorta/) - [Turner syndrome](https://durgical.com/en/conditions/turner-syndrome/) - [Aortic Valve Stenosis](https://durgical.com/en/conditions/aortic-valve-stenosis/) - [Heart failure](https://durgical.com/en/conditions/heart-failure/) [← All of embryology](https://durgical.com/en/embryology/) Educational content on embryonic development; not a guide to prenatal diagnosis or to medicines in pregnancy and no substitute for a health professional's advice. No doses are given. Sources: Langman's Medical Embryology, 13th ed., ch. 13: Cardiovascular System (Wolters Kluwer, 2015); [Coarctation of the Aorta | Congenital Heart Defects (CHDs) | CDC](https://www.cdc.gov/heart-defects/about/coarctation-of-the-aorta.html) (Centers for Disease Control and Prevention, 2024). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/embryology/coarctation-of-the-aorta/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/embryology/coarctation-of-the-aorta/