Coarctation of the aortaL-to-R shunt – ACYANOTIC
  • 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

Co-arctation 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
  • 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

CXRthe ‘3’ sign in the upper left of the chest. After age 5 there may be rib notching (especially 3rd and 8th ribs) due to intercostals hypertension
BP measurements – upper and lower limbs
Echo with Doppler flow
ECG

  • In neonates – RBBB, RVH
  • In older children – LVH

Prognosis

Can result in:

Treatment

The sick neonate:
Then consider surgery:
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

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