Aortic Coarctation Clinical Presentation

The history of those with coarctation of the aorta includes the following.

• Early life: Depending on severity of obstruction and associated cardiac lesions, patients may present with congestive heart failure, severe acidosis, or poor perfusion to the lower body.
• Beyond infancy: Patients are usually asymptomatic. They may present with hypertension, headache, nosebleed, leg cramps, muscle weakness, cold feet, or neurologic changes.

The diagnosis of coarctation generally can be made on physical examination. Blood pressure differential and pulse delay are pathognomonic.

• Physical appearance

  • Patients may appear healthy. If coarctation compromises the origin of the left subclavian artery, the left arm is smaller than normal. Otherwise, general development is normal.
  • In XO Turner syndrome, a condition frequently associated with coarctation, a phenotypic female has the following features: short stature, webbed neck, absent or scanty axillary and pubic hair, broad chest and widely spaced hypoplastic or inverted nipples, low posterior hairline, small chin, prominent ears, cubitus valgus, short fourth metacarpals and metatarsals, distal palmar triaxial radii, narrow hyperconvex nails, and extensive pigmented cutaneous nevi.
• Arterial pulse: Abnormal differences in upper and lower extremity arterial pulses and blood pressures are clinical hallmarks of coarctation of the aorta. Pulses distal to the obstruction are diminished and delayed. This may be appreciated best by simultaneous arm and leg pulse palpation.
• Auscultation

  • A continuous and/or late systolic murmur is best heard posteriorly over the thoracic spine. Collateral arterial murmurs are crescendo-decrescendo in shape and delayed in onset and termination because of their origins in vessels some distance from the heart. The collateral murmurs are present bilaterally.
  • If the patient has associated bicuspid aortic valve, an aortic ejection sound, a short midsystolic murmur, and/or early diastolic murmur of aortic regurgitation may be audible.
• Associated cardiac defects

  • These are observed in approximately 50% of patients with coarctation.
  • The most commonly reported defects are left-sided obstructive or hypoplastic defects and ventricular septal defects. Bicuspid aortic valve is observed in 85% of patients. Also, aortic arch hypoplasia is commonly found in coarctation associated with intracardiac defects.^[1]
  • Right-sided cardiac obstructive lesions, such as pulmonary stenosis, pulmonary atresia, or tetralogy of Fallot, are observed rarely.
• Extracardiac vascular anomalies

  • These commonly occur in patients with coarctation. A right subclavian artery that arises aberrantly from the descending aorta distal to the coarctation occurs in 5% of patients. Rarely, both subclavian arteries originate distal to the coarctation.
  • Berry aneurysms of the circle of Willis occur in 3-5% of patients and may result in subarachnoid bleed.
  • After years of coarctation, large collateral arteries develop from the upper to lower body (ie, internal mammaries connecting to external iliac arteries and spinal and intercostal arteries connecting to the descending aorta).
  • Hemangiomas also have been reported with coarctation.
• Extracardiac nonvascular anomalies

  • Extracardiac nonvascular anomalies occur in 25% of patients with coarctation of the aorta. Coarctation of the aorta occurs in 35% of patients with Turner syndrome.
  • Abnormalities of the musculoskeletal system, genitourinary system, gastrointestinal system, or respiratory system may be observed in as many as 25% of children with coarctation. In addition, an increasing number of children have head and neck abnormalities observed by ultrasonography.

The exact etiology of coarctation of the aorta is not known.

• Genetics: Coarctation is 7 times more common in white persons than Asian persons. It has a lower incidence among Native Americans than other population groups in Minnesota.
• Environment: Environmental variation and seasonal variation have been suggested to influence the development of coarctation. A study has shown increased incidence of coarctation in late fall and winter births.
• Gridlock mutation: In 1995, Weinstein et al discovered a recessive mutation in zebrafish that causes a focal malformation resembling coarctation in humans.^[2] The mutation, named gridlock, results in failure of vascular channel formation at the site where bilaterally paired dorsal aortas join together and continue posteriorly as a dorsal midline channel, the medial dorsal aorta.