Aortic coarctation

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-In-Chief: Priyamvada Singh, M.B.B.S.[2], Cafer Zorkun, M.D., Ph.D. [3]; Assistant Editor(s)-In-Chief: Kristin Feeney, B.S.[4]

Aortic coarctation was first described as early as 1760. In the 1900s Bonnett and Johnson further classified the anatomical variants associated with aortic coarctation.

• Johann Friederich Meckel, Prussian anatomist, introduced the description of coarctation of aorta in 1760.

• In 1903, Bonnett was the first in classify the aortic coarctation into infantile type (diffuse narrowing of the aorta in the region proximal to the ductus arteriosus) and adult type or more abrupt constriction of the aorta just distal to the origin of the left subclavian artery, close to the ductus insertion.

• In 1951, Johnson et al, classified the coarctation based upon the position of the ductus arteriosus and its relation to the coarctation as preductal aortic coarctation and postductal aortic coarctation.

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-In-Chief: Priyamvada Singh, M.B.B.S.[2], Cafer Zorkun, M.D., Ph.D. [3]; Assistant Editor(s)-In-Chief: Kristin Feeney, B.S.[4]

Aortic coarctation can be classified as preductal coarctation, ductal coarctation, and postductal coarctation depending upon the coarctation’s anatomic relationship to the ductus arteriosus. All classifications involve narrowings of the aorta that directly impact the aortic hemodynamics.

Schematic drawing of alternative locations of a coarctation of the aorta, relative to the ductus arteriosus. A: Ductal coarctation, B: Preductal coarctation, C: Postductal coarctation. 1: Aorta ascendens, 2: Arteria pulmonalis, 3: Ductus arteriosus, 4: Aorta descendens, 5: Truncus brachiocephalicus, 6: Arteria carotis communis sinistra, 7: Arteria subclavia sinistra^[1]

There are three variations of coarctation of the aorta:

The narrowing is proximal to the ductus arteriosus. If severe, blood flow to the aorta distal (to lower body) to the narrowing is dependent on a patent ductus arteriosus, and hence its closure can be life-threatening. Preductal coarctation results when an intracardiac anomaly during fetal life decreases blood flow through the left side of the heart, leading to hypoplastic development of the aorta.

The narrowing occurs at the insertion of the ductus arteriosus. This kind usually appears when the ductus arteriosus closes.

The narrowing is distal to the insertion of the ductus arteriosus. Even with an open ductus arteriosus blood flow to the lower body can be impaired. Newborns with this type of coarctation may be critically sick from birth. This type is most common in adults. It is associated with notching of the ribs, hypertension in the upper extremities, and weak pulses in the lower extremities. Postductal coarctation is most likely the result of muscular ductal (ductus arteriosis) extension into the aorta during fetal life.

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-In-Chief: Priyamvada Singh, M.B.B.S.[2], Cafer Zorkun, M.D., Ph.D. [3]; Assistant Editor(s)-In-Chief: Kristin Feeney, B.S.[4]

Like many congenital heart diseases, the cause of aortic coarctation is not clear. The etiology of coarctation of the aorta may be explained by multifactorial inheritance hypothesis. Clinical studies suggest that genetic, familial influence and environmental factors both play an important role during pregnancy. It has been found to be associated more with patients with Turner syndrome. Additional research suggests a possible link between other congenital heart diseases and an aortic coarctation, indicating that those with congenital heart disease are more likely to have an accompanying secondary defect.

• The etiology of coarctation of the aorta may be explained by multifactorial inheritance hypothesis.
• Aortic coarctation is more common in persons with certain genetic disorders, such as Turner syndrome.
• It can also be due to birth defects of the aortic valves. Aortic coarctation is one of the more common heart conditions that are present at birth (congenital heart conditions). It is usually diagnosed in children or adults under age 40. Coarctation of the aorta may be seen with other congenital heart defects, such as: bicuspid aortic valve, defects in which only one ventricle is present, ventricular septal defect
• It has been found to have increased incidences in some families.
• Maternal drug use – Clomifene

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-In-Chief: Priyamvada Singh, M.B.B.S.[2], Cafer Zorkun, M.D., Ph.D. [3]; Assistant Editor(s)-In-Chief: Kristin Feeney, B.S.[4]

A thorough examination is necessary to truly diagnose an aortic coarctation. Conditions with similar symptoms to an aortic coarctation include: aortic stenosis, cardiomyopathies (dilated cardiomyopathy and hypertrophic cardiomyopathy), endocardial fibroelastosis, primary hypertension, hypoplastic left heart syndrome, viral myocarditis, congenital adrenal hyperplasia, patent ductus arteriosus, polyarteritis, sepsis and shock

A number of conditions are associated with the aortic coarctation. During an examination, it is important to be cognizant that the following conditions need to be differentiated from an aortic coarctation:

• Aortic stenosis
• Cardiomyopathies (dilated cardiomyopathy and hypertrophic cardiomyopathy)
• Endocardial fibroelastosis
• Essential hypertension
• Hypoplastic left heart syndrome
• Viral myocarditis
• Circulatory collapse due to hypoadrenalism, congenital adrenal hyperplasia
• Patent ductus arteriosus
• Hypertension
• Polyarteritis
• Sepsis
• Shock

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-In-Chief: Cafer Zorkun, M.D., Ph.D. [2], Priyamvada Singh, M.B.B.S.[3]

Coarctation of the aorta is a common congenital malformation. It occurs in about 7% of patients with congenital heart defects. It is more common in males than females with a ratio of 2:1. Up to 25% of patients with Turner syndrome have coarctation of the aorta. It is 7 times more common among caucasians than asians.

• The diagnosis is often missed in first year of life.
• Generally, patients with coarctation of the aorta present early in life with congestive heart failure or later in life with hypertension.

• It is 2 times more common in males than females.

• Coarctation is 7 times more common among Caucasians than Asians.
• The incidence is lower in Native Americans than Caucasians.

• Aortic coarctation is a common heart defect.
• It forms approximately 6-10% of all congenital heart disease cases.
• In live births, it accounts for approximately 5-7% of congenital heart disease in severely ill infants.

• The prevalence is lower in Asian countries compared to American and European countries.

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-In-Chief: Priyamvada Singh, M.B.B.S.[2], Cafer Zorkun, M.D., Ph.D. [3]; Assistant Editor(s)-In-Chief: Kristin Feeney, B.S.[4]

Risk factors associated with an increased risk of coarctation include genetic anomalies, familial history, environmental factors, and neonatal care.

Like many congenital heart disease, the cause of aortic coarctation is not well defined. Clinical studies suggest that genetic and environmental factors both play an important role during pregnancy. These include:

• Genetic disorders, such as Turner syndrome. As many as 10-25% of patients with Turner syndrome have an accompanying coarctation of the aorta.
• Gender, more common in males than females (2:1 ratio).
• Viral infections during pregnancy.
• Presence of another congenital heart disease, such as:

• Ventricular septal defect
• Patent ductus arteriosus
• Mitral valve stenosis
• Aortic valve stenosis
• Bicuspid aortic valve

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1], Associate Editor-in-Chief: Cafer Zorkun, M.D., Ph.D. [2]

Arterial hypertension in the right arm with normal to low blood pressure in the lower extremities should prompt consideration of the diagnosis of aortic coarctation.

Following findings may be observed during screening of aortic coarctation;

• Blood pressure: Arterial hypertension in the right arm with normal to low blood pressure in the lower extremities is classic. The blood pressure is higher in the upper extremities than in the lower extremities. The patient may complain of a headache due to hypertension.

• Pulses: Femoral pulses are often diminished in strength. Exercise exacerbates this gradient. If the coarctation is situated before the left subclavian artery, the left pulse will be diminished in strength and asynchronous radial pulses will be detected in the right and left arms. A radial-femoral delay between the right arm and the femoral artery may be apparent, while no such delay may be observed with left arm radial-femoral palpation. A coarctation occurring after the left subclavian artery will produce synchronous radial pulses, but radial-femoral delay will be present under palpation in either arm.

• Neck: There may be webbing of the neck in patients with Turner syndrome, 10% of whom have aortic coarctation.

• Heart
  • A systolic ejection click is present when there is an associated bicuspid aortic valve.
  • The S2 is loud secondary to hypertension.
  • An S4 may be present secondary to LVH.
  • There are 3 potential sources of a murmur: arterial collaterals, an associated bicuspid aortic valve, and the coarctation itself which can be heard over the spine.
  • A prominent P2 may be present if there is associated pulmonary hypertension.

• Extremities
  • Cyanosis of the lower extremities may be present.
  • Occasionally adults may have narrow hips and thin legs or have an undeveloped left arm (in those patients in which the coarctation compromises the origin of the subclavian artery).

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-In-Chief: Priyamvada Singh, M.B.B.S.[2], Cafer Zorkun, M.D., Ph.D. [3]; Assistant Editor(s)-In-Chief: Kristin Feeney, B.S.[4]

80% of patients are diagnosed during childhood. In the remaining 20% of cases, the symptoms are often less severe, but the coarctation will ultimately require correction in order to prevent irreversible organ damage. Common complications among patients who go untreated include: aortic rupture, infective endocarditis, congestive heart failure, and calcification of the aorta.

In infants with a preductal coarct, the LV output goes to the upper extremities, and the RV output goes to the lower extremities through the patent ductus.

• Childhood:

• 80% of cases are diagnosed in childhood.
• The preductal form is usually discovered in early infancy because it is usually severe.
• Childhood coarctation is associated with a ventricular septal defect (VSD), tubular hypoplasia of the aortic arch, transposition of the great vessels, and mitral valve disease.

• Adolescence:

• When first recognized in adolescents, coarctation of the aorta is generally asymptomatic.

• Adulthood:

• The postductal form is often less severe and discovered in adulthood.
• Infrequently coarctation of the aorta is associated with other congenital abnormalities.
• In patients over the age of 30, major complications leading to death are not uncommon. ^[1][2]

• 75% of patients with coarctation will have hypertension at 30 years of their age.

• If the coarctation is left untreated, arterial hypertension may become permanent due to irreversible changes in some organs (such as the kidney).

About 50% of patients with coarctation of the aorta die within the first three decades of life, and more than 75% are dead by age 50 due to:

• Rupture of the aorta or aortic dissection
  • Most frequently in the third or fourth decade.
  • Dissections originate either proximally (secondary to hypertension and local stress)or distally (where the jet erodes the intima).
  • Ruptures may bleed into the esophagus, and hematemesis or melena may portend disaster.

• Infective endocarditis or endarteritis
  • Most frequently in the second to fourth decade of life.

• Rupture of the circle of Willis
  • Most frequently in the second or third decade of life.
  • Secondary to the increased incidence of aneurysms in this population and the presence of proximal hypertension.

• Congestive heart failure
  • Common in infants, often occurs with associated abnormalities such as VSD or mitral valve disease.
  • In the adult is secondary to hypertension associated with coronary artery disease or aortic valve disease.

• Calcified aortic stenosis
  • Result of associated bicuspid aortic valve disease that over time becomes calcified.

• Premature death occurs due to
  • Coronary artery disease
  • Heart failure
  • Stroke
  • Aortic dissection or rupture

Prognosis is variable. The prognosis of aortic coarctation depends on whether balloon angioplasty and stenting or the surgery has been done or not.

• The mortality rate of aortic coarctation depends largely on the age of surgical repair. Left untreated, less than 20% of untreated patients live to the age of 50. However, with surgical repair, mortality rates are far lower and survival is prolonged.
• If repaired by the age of 14, the mortality rate during the 20 years following is only 9% (a 91% survival rate).
• If repaired later than age 14, the mortality rate is 11% (a 79% survival rate).
• Among expectant mothers with a coarctation of the aorta, the maternal mortality rate ranges between 3-8%. Even with repair, there is a risk of developing complications during pregnancy.

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