Coarctation of the aorta

• Coarctation of the aorta is a type of outflow tract obstruction
• Pathophysiology:

  • Narrowing of the aortic arch - usually around the ductus arteriosus
  • Obstruction to the left ventricles outflow tract leads to increase in left ventricular afterload which causes left ventricular hypertrophy
  • Neonates with severe aortic coarctation can develop heart failure
  • Associated with Turner's syndrome (5-15% of girls with coarctation)
• Time of presentation:

  • Symptoms usually present 3-5 days after birth when the duct begins to close
  • PDA and foramen ovale allows blood to bypass the outflow obstruction
• Clinical exam:

  • Absent/weak femoral pulses (do 4-limb BP measurement) - radio-femoral delay
  • Systolic blood pressure is high when measured with BP cuff
  • Cold extremities (especially feet)
  • Hepatomegaly in heart failure due to severe coarctation
  • Systolic murmur heard at the back between the scapulae/under the left scapula
• Additional signs may develop over time:

  • Left ventricular heave due to left ventricular hypertrophy
  • Underdeveloped left arm where there is reduced flow to the left subclavian artery
  • Underdevelopment of the legs
• Investigations:

  • Echocardiogram and doppler - direct visualisation of defect
  • ECG
  • CXR
• Management:

  • Depends on severity of coarctation
  • In severe cases patients will require emergency surgery shortly after birth
  • In severe cases - continuous IV infusion of prostaglandin E1 to keep the ductus arteriosus open whilst waiting for surgery - allows blood flow through the ductus arteriosus into the systemic circulation distal to the coarctation
  • Surgery then performed to correct defect - can be stent insertion or surgical repair