Coarctation of the Aorta

Key Features

Essentials of Diagnosis

• Absent or diminished femoral pulses

• Upper to lower extremity systolic blood pressure gradient of > 20 mm Hg

• Blowing systolic murmur in the back or left axilla

General Considerations

• Defined as narrowing in the aortic arch that usually occurs in the proximal descending aorta near the takeoff of the left subclavian artery near the ductus arteriosus

• Accounts for about 6% of all congenital heart disease

• Three times as many males as females are affected

• Presents insidiously in 60% of children with no symptoms in infancy

• Many affected females have Turner syndrome

• Incidence of associated bicuspid aortic valve with coarctation is 80–85%

• The abdominal aorta is rarely involved

Clinical Findings

Symptoms and Signs

• Decreased or absent femoral pulses

• Infants with severe coarctation have equal upper and lower extremity pulses from birth until the ductus arteriosus closes

• Heart failure in first month of life may be caused by

  • Coarctation alone

  • Coarctation combination with ventricular septal defect, atrial septal defect, or other congenital cardiac anomalies

• Pulse and blood pressure (> 15 mm Hg) discrepancy between the arms and legs

• Pulses in the legs are diminished or absent

• The left subclavian artery is occasionally involved in the coarctation, in which case the left brachial pulse is also weak

• Pathognomonic murmur is heard in the left axilla and the left back

• Systolic ejection murmur is often heard at the aortic area and the lower left sternal border along with an apical ejection click if there is an associated bicuspid aortic valve

Diagnosis

Imaging

• Chest radiography

  • May show a normal-sized heart or more often some degree of left ventricular (LV) enlargement

  • Aorta proximal to the coarctation is prominent

  • Aortic outline may indent at the level of the coarctation

  • Poststenotic segment is often dilated

  • This combination of abnormalities results in the "figure 3" sign

  • Notching of the ribs caused by marked enlargement of the intercostal collaterals

  • Marked cardiac enlargement and pulmonary venous congestion occur in patients with severe coarctation and associated heart failure

• Echocardiography

  • Two-dimensional echocardiography and color-flow Doppler are used to visualize the coarctation directly

  • Continuous-wave Doppler estimates the degree of obstruction

Diagnostic Procedures

• Electrocardiography

  • May be normal or may show LV hypertrophy in older children

  • Usually shows right ventricular hypertrophy in infants with severe coarctation because the right ventricle serves as the systemic ventricle during fetal life

• Cardiac catheterization and angiocardiography

  • Rarely performed for diagnosis in infants or children with coarctation

  • Used, however, when transcatheter intervention is planned

Treatment

• Resuscitative measures include PGE₂ infusion (0.05–0.1 μg/kg/min) to reopen the ductus arteriosus

• Inotropic support is frequently needed for end-organ damage distal to the coarctation

• Once stabilized, the infant should ...