Contents
Introduction
Coarctation of the aorta (also sometimes called aortic coarctation) is a congenital heart condition that causes a narrowing of the aorta, which increases strain on the heart.
Many cases are mild and may not be picked up until later in life. More severe cases present in newborn babies, often with difficulty breathing, difficulty feeding (as the baby struggles to breathe and feed simultaneously).
A classical presentation would cause high blood pressure in the arms and low blood pressure in the legs.
Coarctation of the aorta is a L-to-R shunt – which typically presents as an ACYANOTIC presentation
- Accounts for up to 10% of congential heart defects
- Male:female ratio is 2:1
- Affects 10-20% of patients with Turner’s Syndrome
- Almost always affects the thoracic aorta, virtually never the abdominal
Clinical features
- Collapse at 3 days of age when the PDA naturally closes. The closing of the PDA suddenly creates lots of Afterload.
- Grey baby
- Upper body hypertension, lower body hypotension
- If very severe:
- Renal failure – due to hypoperfusion. May result in Acidosis
- Heart failure
- If minor
- May be asymptomatic in young children. Signs may appear as the child grows, such as:
- Headaches, chest pain, fatigue, claudication in the legs (particularly during physical activity)
- Heart failure is unlikely to occur if it has not appeared during the neonatal period
Pathology
Coarctation of the aorta is where there is a narrowing of the aorta in the region of the ductus arteriosus. it can be divided into three types:
Narrowing is proximal to ductus arteriosus
Narrowing is proximal to ductus arteriosus
- A PDA can be life-saving (consider IV prostaglandins)
- Usually the result of abnormally low blood flow in the left side of the heart during fetal life, resulting in hypoplasia of the aorta
Narrowing at the ductus arteriosus
- Occurs when the DA closes
Narrowing distal to the ductus arteriosus
Examination Findings
- Hypertension in the upper limbs
- Reduced / absent femoral pulses
- Low BP in the lower limbs
- Murmur
- Usually grade 2/3
- Left sterna edge
- Murmurs in the intercostals spaces – may be heard due to dilation of the intercostal arteries
Signs of Turner’s syndrome in females:
- Webbed neck
- Lymphoedema in the feet
- Square chest
- Widely spaced nipples
Diagnosis
CXR – the ‘3’ sign in the upper left of the chest. After age 5 there may be rib notching (especially 3rd and 8th ribs) due to intercostal hypertension
BP measurements – upper and lower limbs
Echo – with Doppler flow
ECG
- In neonates – RBBB, RVH
- In older children – LVH
Prognosis
Can result in:
- Left ventricular hypertrophy
- Aortic rupture
- Intracranial haemorrhage
- Hypertensive cardiovascular disease in adult life
Treatment
The sick neonate:
- Correct acidosis
- Fluids + frusemide
- High pressure ventilation
- IV prostaglandins
- Correct hypertension
- ACE inhibitors should be avoided
- Consider beta-blockers
Then consider surgery:
Surgical balloon treatment +stenting
Surgical balloon treatment +stenting
- 80-90% effective
- Further balloon treatment as the child grows can help dilate the stent
Surgical repair
- Less common since advent of balloon treatment
- 5% mortality in symptomatic children
- 1% mortality in asymptomatic children
- Only 65-90% effective
- Rarely can cause paraplegia due to aortic clamping during the surgery
All patients need prophylaxis for infective endocarditis before surgery, e.g.:
- Amoxicillin – PO 1 hr before surgery – 50mg/Kg, or, if allergic to penicillin:
- Clindamycin – 20mg / Kg
References
- Murtagh’s General Practice. 6th Ed. (2015) John Murtagh, Jill Rosenblatt
- Oxford Handbook of General Practice. 3rd Ed. (2010) Simon, C., Everitt, H., van Drop, F.
- Beers, MH., Porter RS., Jones, TV., Kaplan JL., Berkwits, M. The Merck Manual of Diagnosis and Therapy