Coarctation of the aorta (COA) is a congenital heart defect that develops
in the fetus. It involves a constricture of the aorta, the main artery
that delivers blood from the
left ventricle of the heart to the rest of the body. In a constricture or
coarctation, the sides (walls) of the aorta press together abnormally,
impeding the flow of blood. COA can produce symptoms of congestive heart
failure or high blood pressure (
) as early as the first week of life or may produce no symptoms until
later in life.
In the fetus, blood from the heart to the lungs is delivered into the
aorta through a short blood vessel called the ductus arteriosis. This duct
or shunt normally closes at birth or shortly after. In symptomatic
children with COA, the descending aorta receives blood from the right side
of the heart through the ductus arteriosus, an abnormal condition often
accompanying other heart abnormalities such as a duct that does not close
patent ductus arteriosus
or PDA), mitral valve defects, and other types of
congenital heart disease
. In asymptomatic children with COA, the descending aorta receives left
ventricle blood through the ascending aorta; these children have fewer, if
any, associated cardiac abnormalities. Approximately 10 percent of
newborns with congenital heart disease have symptomatic coarctation of the
aorta. About 85 percent of all children and adults with COA have a double
aortic valve (bicuspid aortic valve) in the heart.
Blood normally leaves the heart by way of the left ventricle and is
distributed to the body through the arteries. The aortic arch is the first
artery to carry blood as it leaves the heart. Other arteries to the head
and arms branch off the aortic arch. Constriction of the aorta, as in COA,
produces resistance to the flow of blood, resulting in raising the blood
pressure above the narrowing and reducing blood pressure below or
downstream from the narrowing. High blood pressure (hypertension) affects
parts of the body supplied by arteries that branch off the aortic arch
above the narrowing. By contrast, most of the lower body does not receive
enough blood supply. To compensate for this, the heart works harder, and
blood pressure rises.
About half of all infants with COA are diagnosed within the first three
months of life. Frequently, other congenital cardiac complications are
also present. Thirty percent of infants with
, for example, also have coarctation. Evidence exists that at least some
cases of coarctation may be inherited.
Coarctation of the aorta is present in about 8 to 10 percent of infants
born with other congenital heart defects, occurring approximately twice as
many males as females.
Causes and symptoms
COA is congenital, that is it develops while the baby is in the womb and
may appear in newborns along with other signs of congenital heart disease.
Among the consequences of COA is an enlargement of the left ventricle
(ventricular hypertrophy) in response to increased back-pressure of the
blood and the demand for more blood by the lower body. Symptoms in infants
may include shortness of breath (dyspnea), difficulty in feeding, and poor
weight gain. Children can also have no symptoms at all at birth
(asymptomatic) and develop mild symptoms as older children. The older
child with COA may display fatigue, shortness of breath, or a feeling of
weakness or lameness in the legs.
COA is typically diagnosed within the first three months of life because
of circulatory problems that produce symptoms. Some children have surgery,
and some children are managed with drug therapy alone. Parents learn to
recognize symptoms of high blood pressure or insufficient blood supply to
the lower extremities. Medical attention is needed at the first sign of
shortness of breath. Even when a child has had surgery or is on
medication, the doctor should be contacted when any abnormal symptoms
arise, such as shortness of breath, difficulty in feeding (with infants),
and poor weight gain. Older children generally have fewer symptoms but may
appear to be easily fatigued or to experience shortness of breath or
weakness or lameness in their legs.
Physical examination may reveal a pale child with some degree of dyspnea.
On examination of the heart rhythm using a stethoscope, infants with
coarctation of the aorta usually have an abnormal "gallop"
heart rhythm, and 50 percent of children also have
. Sometimes excessive arterial pulses can be seen in the arteries of the
neck (carotid and suprasternal notch arteries), indicating increased
pressure in these arteries, while the major artery of the legs (femoral
artery) may have a weak pulse or none can be detected. The systolic
pressure is higher in the arms than in the legs. Enlargement of the heart
can be seen in x rays and congestion of the blood vessels in the lungs.
Similar symptoms may be seen in older children and adults. A 10 mm Hg
(mercury) pressure difference between the upper and lower extremities is
diagnostic for coarctation of the aorta. For some individuals, the
systolic pressure difference is observed only during
. Infants frequently have an abnormal electrocardiogram (ECG) that
indicates that the right or both ventricles are enlarged, while in older
the ECG may be normal or show that the left ventricle is enlarged. The
site and the extent of coarctation may also be detected using color-flow
Doppler ultrasonography (echocardiology).
Asymptomatic children may have a normal heart size or only slight
enlargement. Differences in blood pressure between the arms and legs may
be noted. Hypertension is less likely and, if noted, may be less marked
than in symptomatic children with other heart defects. The bicuspid aortic
valve is usually present. Color-flow Doppler studies may show a reduced
blood flow below the coarctation.
The goal of treatment in children is to reopen the ductus arteriosus and
restore blood flow to the descending aorta. Congestive heart failure may
be treated simultaneously with anticongestive medications. Drug therapy is
used first to treat hypertension and heart failure in children and adults
who have coarctation of the aorta. Surgery may be required for infants who
have severe coarctation of the aorta and is usually recommended for those
who have associated cardiac defects or those infants who do not respond to
drug therapy. Surgery may also be indicated for infants whose early
symptoms do not indicate immediate surgery but who develop severe
hypertension during the first several months of life. Older children and
adults are advised to avoid vigorous exercise prior to surgical correction
of the coarctation. Surgery may involve resection of the coarctation
segment or opening and patching the aorta where the coarctation occurred.
Balloon angioplasty is sometimes performed on infants who are not ideal
candidates for repair surgery because of higher risk; this procedure
involves passing a catheter with an attached deflated balloon through the
femoral artery in the groin and inflating the balloon to open the
coarctation segment of the aorta. Recoarctation can occur in some
individuals, even after corrective surgery. Recurrence is higher with
balloon angioplasty than with repair surgery.
Approximately half of all infants diagnosed with coarctation of the aorta
have no other cardiac defects and respond well to medical management,
growing and developing normally. These infants are generally asymptomatic
and will eventually outgrow the condition after several years of life.
Although hypertension may increase for several months early in life, it
eventually decreases as the circulatory system develops and vessels become
Symptomatic children who have other heart defects generally respond well
to repair surgery, and COA symptoms are reduced. The mortality rate for
COA infants is about 5 percent. The average life span of children who have
coarctation of the aorta is 34 years of age, reduced primarily due to
complications and to the presence of other heart problems. The most common
complications following repair surgery are postoperative renal failure and
recoarctation. Complications in children who have not had surgery are
hypertension, aortic rupture, intracranial bleeding, and congestive heart
failure. Undetected or untreated COA can also lead to early adulthood
death due to congestive heart failure, systemic hypertension, coronary
artery disease, and aortic aneurysm. Women who have an uncorrected
coarctation of the aorta have a mortality rate of 10 percent during
pregnancy and a 90 percent rate of complications.
Because congenital coarctation of the aorta is unpredicted, parents may be
unprepared for the diagnosis and need careful, sensitive medical
explanation by the pediatrician or surgeon. The birth of a child with this
condition may raise parents' concerns about their child's
ability to lead a normal life. If COA is detected, with or without the
child's presenting symptoms, medical and surgical treatment usually
corrects the condition and reduces symptoms. Over half of children
overcome the condition and grow and develop normally without severe
restrictions. Children who have other heart problems may have the repair
surgery and other procedures to reduce symptoms and improve blood flow and
with continued drug therapy and some restrictions on activity can lead
relatively normal lives into adulthood.
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L. Lee Culvert John T. Lohr, PhD