Brief Summary of Coarctation of Aorta

Critical neonatal coarctation of the aorta is associated with ductal-dependent systemic blood flow provided by the RV.

Age of Presentation: Most often these infants present to a hospital at 2 to 6 weeks of life with a history of feeding and respiratory difficulties as the ductus arteriosus closes.

Clinical Features: The clinical exam suggests neonatal sepsis with gray mottled skin color and poor perfusion, tachypnea, and poor pulses. A murmur may not be apparent and hepatomegaly and gallop rhythm may be more detectable after fluid resuscitation. Oximetry may not reveal significant desaturation. Cardiomegaly is usually present on a chest radiograph.
Older children with coarctation usually have no symptoms but may have hypertension incidentally detected (especially if measured in the right arm). Femoral pulses can be present in the older child with coarctation due to flow through collateral vessels, and foot pulses may seem almost normal. However, palpation of femoral arterial pulse simultaneously with right brachial pulses will reveal the delay in femoral pulse and the relative decrease in amplitude.
A small number of infants will have noncritical but severe coarctation and present in the first 6 months of life with symptoms of congestive heart failure but without the picture of shock seen in the young infant with critical coarctation.

Management
Most infants with critical pulmonic valve stenosis will undergo urgent balloon dilation of the pulmonic valve in the catheterization lab. The infant with critical coarctation or critical aortic stenosis in cardiogenic shock requires stabilization by establishing patency of the ductus arteriosus to allow the RV to provide systemic blood flow below the aortic obstruction. Alprostadil (prostaglandin E1 infusion) can often accomplish this, but inotropic support with dopamine or dobutamine is often needed. This is followed by judicious use of diuretics to establish urine output and relieve pulmonary edema. Ventilator support is usually needed, but attempts to maintain minimal FiO2 (often 21%) are important. High inspired FiO2 acts as a pulmonary vasodilator and can “steal” systemic circulation to the pulmonary vascular bed. Treatment for sepsis is often initiated in these infants before the diagnosis of cardiogenic shock is made. Continuation of antibiotic treatment may be advisable pending culture results, as these infants have an increased incidence of concomitant gram-negative sepsis, perhaps secondary to poor perfusion of the bowel.
The older infant with severe coarctation or aortic stenosis with congestive heart failure without shock requires surgical or catheter treatment. Surgical correction is the most common approach used for infants with coarctation. Catheter dilation has a more established record in the treatment of infants with severe aortic valve stenosis. Aortic valvotomy by catheter dilation or by surgery is palliative and will be followed by more definitive operation in the older child. In most cases the Ross operation is performed, in which the patient’s native pulmonic valve is autotransplanted into the aortic position. A composite homograft pulmonic valve is used to replace the normal native pulmonic valve that has been placed in the aortic position. This approach seems to afford the best chance for long-term correction of aortic valve disease without the need for warfarin anticoagulation mandated by the use of mechanical valve prosthetics.