Coarctation of the Aorta

COARCTATION OF THE AORTA

Coarctation of the aorta comprises 8-10% of all congenital heart disease. In up to 85% of cases, there is an association with a bicuspid aortic valve. Other cardiac anomalies including PDA and VSD may be associated. The incidence in males is twice that of females and 1/3 of Turner's syndrome (XO) patients has a coarctation.

In 98% of cases, the constriction is located at the junction of the ductus arteriosus (juxtaductal) below the origin of the left subclavian artery.

Clinical features:

The severity and location of the coarctation will determine the age and features of the clinical presentation.

1. In utero, the present of the ductus allows blood to bypass the aortic narrowing

2. Severe narrowing will present in infancy with poor perfusion, metabolic acidosis, shock, and congestive heart failure. This may be delayed until a few weeks of life when the ductus arteriosus closes

3. Less severe disease can present later in childhood or even in adulthood with hypertension and headaches. An elevated blood pressure may be the only sign. There is development of extensive collateral vessels to bypass the narrowed segment of the aorta. This may present with rib notching on radiographic exams.

Diagnosis:

1. Discrepancy in UE and LE blood pressure (UE > LE). Normally, the lower extremity pressures are higher.

2. Delayed or weakened femoral pulses compared to brachial or radial pulses. Palpation should be done simultaneously. Normally, the femoral pulse is felt before the radial pulse.

3. A murmur may be present over the precordium or the upper back. Usually systolic but may extend into diastole.

4. Newborns may have a discrepancy in pre- and post-ductual oxygen saturation.

5. Echocardiogram and cardiac catherization: confirm the diagnosis, and are also useful in defining the patient’s cardiac anatomy and defining other anomalies. .

Therapy:

1. Surgery

a. In neonates, definitive surgery when the baby is stabilized

b. If diagnosis is delayed, correction should be done when diagnosis is made.

i. Resection with end-to-end anastomosis

ii. Left subclavian artery flap

iii. Patch aortoplasty

iv .Angioplasty/stent

2. For infants in shock, initial therapy includes the administration of prostaglandin E1 to keep or reopen the ductus to improve systemic blood flow

3. Inotropic agents and/or diuretics.

4. Patients will require long-term follow up to monitor for re-stenosis, hypertension and aneurysm formation. They should also receive SBE prophylaxis.