Coarctation of the aorta refers to a narrowing of the aorta at, or distal to, the origin of the left subclavian artery (where the ductus arteriosus inserts).
Severe narrowing encourages the formation of collateral arterial circulation using the intercostal and periscapular arteries. There may be renal hypoperfusion, which leads to systemic hypertension via activation of the renin-angiotensin system.
Coarctation is an important cause of heart failure in neonates. It only presents with symptoms if coarctation is severe enough.
Children and adults
Usually asymptomatic for many years.
Possible presentations include:
- Hypertension, which can lead to headaches and nosebleeds
- Cold legs due to poor blood flow
Signs may include:
- Radiofemoral delay (if coarctation distal to subclavian artery)
- Radioradial delay (if presubclavian coarctation)
- Hypertension in upper limbs – >20 mmHg difference between upper and lower limbs
- Mid- or late-systolic murmur
- Chest x-ray: normal in childhood. Later in life, it shows rib notching and dilated/indented aorta
- MRI/CT scan: most important investigations for diagnosing coarctation
- ECG: left ventricular hypertrophy
- Echocardiography: can confirm diagnosis but operator-dependent
Surgical excision of coarctation with end-to-end anastomosis is the definitive treatment for coarctation of the aorta. In early childhood, this usually resolves hypertension. However, in adolescents and adults receiving this surgery, hypertension persists in 70%.
Indications: >30 mmHg pressure gradient across coarctation
- Heart failure: usually in infants
- Hypertension: usually later in life
- Aortic dissection
- Cerebral haemorrhage