Coarctation of the Aorta


Albert P. Rocchini, M.D.
Professor of Pediatrics
University of Michigan

What is coarctation of the aorta?

Coarctation of the aorta is a narrowing of the aorta that causes a blockage to blood
flow. Most coarctations are congenital (meaning they are present at birth) and usually
are discovered in infancy; however, some coarctations can develop over time. The
narrowing may be discrete or may extend over a long segment. Most coarctations are
located in the chest, and rarely they can occur in the abdomen. “Simple” is the
term used to describe coarctations that are isolated; “complex” is the term used
to describe coarctations that are associated with other congenital heart disease.
Types of congenital heart disease associated with coarctation include ventricular
septal defect (an abnormal hole between the two ventricles), atrioventricular canal
(an abnormal connection between the atrium and the ventricle), and double outlet
right ventricle (two exit vessels from the ventricle, rather than one).

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Who gets coarctation of the aorta?

Coarctation of the aorta is one of the more common forms of congenital heart disease.
It is twice as common in boy as in girls. Coarctation rarely runs in families. The
only syndrome that has a strong association with coarctation is Turner’s syndrome,
a condition in which a girl has only one instead of two X chromosomes.

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What are the effects of this defect on my child’s health?

Infants with coarctation frequently have congestive heart failure (the heart cannot
keep up with its workload, so it starts to fail). A narrowing of the aorta results
in a selective elevation in blood pressure in the upper extremity blood vessels
and, ultimately, in an increase in heart work. In some newborns with coarctation,
closure of the ductus arteriosus results in an acute increase in heart work. If
the coarctation is severe, the increased heart work results in the development of
congestive heart failure. In infants with milder degrees of coarctation, the heart
adapts to the increase in work, and heart failure does not occur.

The cardiovascular system has two ways to respond to the increased work produced
by coarctation of the aorta. The first way the body compensates for the increased
cardiac workload is to develop extra heart muscle (myocardial hypertrophy). The
second way is to develop collateral vessels to bypass the aortic obstruction. As
the child develops these alternate blood channels, the blood pressure and the cardiac
work are reduced, and there is an improvement in blood supply to the abdominal organs,
such as the liver, the gastrointestinal tract, and the kidneys.

Cardiovascular lesions can aggravate the heart’s burden associated with coarctation.
The presence of a coarctation will increase the amount of blood flow across a ventricular
septal defect, making a small hole act (as far as the heart is concerned) as if
it were a large hole.

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How is this problem diagnosed?

Clinical features of coarctation

Most children with coarctation have no symptoms. In older children, if symptoms
are present, they are usually nonspecific and relate either to high blood pressure
(hypertension) in the upper part of the body, causing headaches or frequent nose
bleeds, or to reduced blood supply to the lower extremities (e.g., exercise-induced
leg pain, claudication).

In infancy, coarctation can be associated with congestive heart failure. Although
heart failure can develop in an infant at any time during the first six months,
it typically develops during the first six weeks. The major features associated
with heart failure are a rapid heart and respiratory rate and poor weight gain.
The infant in heart failure needs to be diagnosed and treated immediately, since
the infant rapidly can develop shock that can result in death.

Physical findings in coarctation

The hallmarks of coarctation of the aorta are absent leg pulses and a difference
in blood pressure between the arms and the legs (i.e., high blood pressure in the
arms and low to normal blood pressure in the legs). The typical heart murmur associated
with a coarctation is a systolic murmur that is loudest in the back below the left
shoulder blade (scapula). If a prominent back murmur is not heard and the child
has a blood pressure difference between the arms and the legs, a coarctation located
in the abdomen should be considered.

Laboratory findings in coarctation

The chest x-ray can be very helpful in suggesting the presence of coarctation of
the aorta. However, the diagnosis usually is confirmed by an echocardiogram (a specialized
ultrasound of the heart). A heart catheterization is performed only if the coarctation
cannot be adequately documented by the echocardiogram or to treat the coarctation
with the use of a balloon angioplasty.

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How is coarctation of the aorta treated?

Management of a patient with coarctation of the aorta must be individualized. In
children without symptoms, in whom a coarctation is diagnosed on routine examination,
repair of the coarctation-either surgically or using balloon angioplasty at a cardiac
catheterization-is not recommended before 18 to 24 months of age.

In the newborn or infant with coarctation who presents in congestive heart failure,
initial treatment consists of stabilizing the infant with medications. These medications
include agents that increase the strength of the heartbeat, inotropic agents, and
agents that help the body remove excess fluids, diuretics. If the infant is less
than two weeks of age, a medicine (prostaglandin E1) will be administered to keep
open the ductus arteriosus. The most critically ill babies will require the use
of a ventilator to assist with breathing. After a brief period of stabilization,
all infants with coarctation and congestive heart failure require surgical repair.

Surgical repair involves removal of the narrowed segment of aorta. In some children,
it is necessary to place a piece of artifical material (e.g., Dacron, Gore-Tex)
to enlarge the area of narrowing or to bypass the area of narrowing. A balloon angioplasty
is performed at the time of a heart catheterization. The angioplasty involves the
placement of a special balloon catheter across the narrowed area and then inflating
the balloon, thereby stretching open the aorta.

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Why treat children with coarctation of the aorta?

Untreated coarctation of the aorta significantly reduces life expectancy, with death
frequently occurring within a patient’s fourth to fifth decade. Causes of death
in individuals with unoperated coarctation of the aorta include congestive heart
failure, aortic rupture (the aorta bursts), bacterial endocarditis (an infection
of the heart), and stroke.

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What is the outlook for children with coarctation of the aorta?

The long-term outlook for children who have had their coarctation repaired, either
with surgery or angioplasty, is excellent. Children who have successful repair of
coarctation usually can live full and productive lives. Women usually can become
pregnant safely. However, medical problems can occur after repair.

Recoarctation

Recoarctation is the redevelopment of a narrowing in the aorta. This problem occurs
more commonly in children who have had their coarctation repaired during the first
year of life. Recoarctation occurs in approximately 10% to 20% of children who have
had their repair in infancy, and in less than 3% of children who have had their
repair after 3 years of age. Treatment of recoarctation of the aorta usually is
with a balloon angioplasty.

High blood pressure

High blood pressure is one of the most common medical problems seen in patients
after successful repair of coarctation. Approximately 60% of people who have had
their coarctation repaired will require medication to treat high blood pressure
in adulthood.

Other medical problems

Other medical problems, which are seen rarely in people after successful repair
of coarctation, include the development of aneurysms in the aorta, the early development
of coronary artery disease, the development of disease to the aortic valve, and
the development of a stroke.

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References

Beekman R, Rocchini A. Coarctation of the aorta and interruption of the aortic arch.
In: Moller J, Neal W, eds. Fetal, neonatal, and infant cardiac disease. Norwalk,
CT: Appleton and Lange, 1990:497-521.

Keith J. Coarctation of the aorta. In: Keith J, Rowe R, Valad P, eds. Heart disease
in infancy and children.
New York: MacMillan, 1978.

About the Author

Dr. Rocchini received both his bachelor of science degree in chemical engineering
and his medical degree from the University of Pittsburgh. He completed his pediatric
residency at the University of Minnesota and his pediatric cardiology fellowship
at the Children’s Hospital of Boston. Dr. Rocchini is currently a professor of pediatrics
and serves as director of pediatric cardiology at the University of Michigan. His
research interests include interventional cardiac catheterization and obesity-induced
hypertension.

Copyright 2012 Albert P. Rocchini, M.D., All Rights Reserved