Coarctation
of the Aorta
Coarctation
of the aorta is a congenital (present at birth)
heart
defect involving a narrowing of the aorta. The
aorta is the large artery that carries oxygen-rich
(red) blood from the left ventricle to the body.
It is shaped like a candy cane, with the first
section moving up towards the head (ascending
aorta), then curving in a C-shape as smaller arteries
that are attached to it carry blood to the head
and arms (aortic arch). After the curve, the aorta
becomes straight again, and moves downward towards
the abdomen, carrying blood to the lower part
of the body (descending aorta).
The
narrowed segment called coarctation can occur
anywhere in the aorta, but is most likely to happen
in the segment just after the aortic arch. This
narrowing restricts the amount of oxygen-rich
(red) blood that can travel to the lower part
of the body. Varying degrees of narrowing can
occur.
The
more severe the narrowing, the more symptomatic
a child will be, and the earlier the problem will
be noticed. In some cases, coarctation is noted
in infancy. In others, however, it may not be
noted until school-age or adolescence.
Seventy-five
percent of children with coarctation of the aorta
also have a bicuspid aortic valve - a valve that
has two leaflets instead of the usual three.
Coarctation
of the aorta occurs in about 8 percent to 11 percent
of all children with congenital heart disease.
Boys have the defect twice as often as girls do.
Some
congenital heart defects may have a genetic link,
either occurring due to a defect in a gene, a
chromosome abnormality, or environmental exposure,
causing heart problems to occur more often in
certain families. Most of the time this heart
defect occurs sporadically (by chance), with no
clear reason for its development.
Coarctation
of the aorta causes several problems, including
the following:
- The left ventricle
has to work harder to try to move blood through
the narrowing in the aorta. Eventually, the
left ventricle is no longer able to handle the
extra workload, and it fails to pump blood to
the body efficiently.
- Blood pressure is higher
above the narrowing, and lower below the narrowing.
Older children may have headaches from too much
pressure in the vessels in the head, or cramps
in the legs or abdomen from too little blood
flow in that region. Also, the kidneys may not
make enough urine since they require a certain
amount of blood flow and a certain blood pressure
to perform this task.
- The walls of the ascending
aorta, the aortic arch, or any of the arteries
in the head and arms may become weakened by
high pressure. Spontaneous tears in any of these
arteries can occur, which can cause a stroke
or uncontrollable bleeding.
- There is a higher than
average chance of developing an infection in
the lining of the heart or aorta known as bacterial
endocarditis.
- The coronary arteries,
which supply oxygen-rich (red) blood to the
heart muscle, may narrow in response to elevated
pressure.
Symptoms
noted in early infancy are caused by moderate
to severe aortic narrowing. The following are
the most common symptoms of coarctation of the
aorta. However, each child may experience symptoms
differently. Symptoms may include:
- irritability
- pale skin
- sweating
- heavy and/or rapid
breathing
- poor feeding
- poor weight gain
- cold feet and/or legs
- diminished or absent
pulses in the feet
- blood pressure in the
arms significantly greater than the blood pressure
in the legs
Mild
narrowing may not cause symptoms at all. Often,
a school-aged child or adolescent is simply noted
to have high blood pressure or a heart murmur
on a physical examination. Some may complain of
headaches or cramps in the lower sections of the
body.
The
symptoms of coarctation of the aorta may resemble
other medical conditions or heart problems. Always
consult your child's physician for a diagnosis.
Your
child's physician may have heard a heart murmur
during a physical examination, and referred your
child to a pediatric cardiologist for a diagnosis.
A heart murmur is simply a noise caused by the
turbulence of blood flowing through the obstruction
from the right ventricle to the pulmonary artery.
Symptoms your child exhibits will also help with
the diagnosis.
A pediatric
cardiologist specializes in the diagnosis and
medical management of congenital heart defects,
as well as heart problems that may develop later
in childhood. The cardiologist will perform a
physical examination, listening to your child's
heart and lungs, and make other observations that
help in the diagnosis. The location within the
chest that the murmur is heard best, as well as
the loudness and quality of the murmur (harsh,
blowing, etc.) will give the cardiologist an initial
idea of which heart problem your child may have.
However, other tests are needed to help with the
diagnosis, and may include the following:
- chest x-ray -
diagnostic test which uses invisible electromagnetic
energy beams to produce images of internal tissues,
bones, and organs onto film.
- electrocardiogram
(ECG or EKG) - a test that records
the electrical activity of the heart, shows
abnormal rhythms (arrhythmias or dysrhythmias),
and detects heart muscle damage.
- echocardiogram (echo)
- a procedure that evaluates the
structure and function of the heart by using
sound waves recorded on an electronic sensor
that produce a moving picture of the heart and
heart valves.
- magnetic resonance
imaging (MRI) - a diagnostic procedure
that uses a combination of large magnets, radiofrequencies,
and a computer to produce detailed images of
organs and structures within the body.
Specific
treatment for coarctation of the aorta will be
determined by your child's physician based on:
- your child's age, overall
health, and medical history
- extent of the disease
- your child's tolerance
for specific medications, procedures, or therapies
- expectations for the
course of the defect
- your opinion or preference
Coarctation
of the aorta is treated with repair of the narrowed
vessel. Several options are currently available.
- interventional cardiac
catheterization
The cardiac catheterization procedure may also
be an option for treatment. During the procedure,
the child is sedated and a small, thin, flexible
tube (catheter) is inserted into a blood vessel
in the groin and guided to the inside of the
heart. Once the catheter is in the heart, the
cardiologist will pass an inflated balloon through
the narrowed section of the aorta to stretch
the area open. A small device, called a stent,
may also be placed in the narrowed area after
the balloon dilation to keep the aorta open.
Overnight observation in the hospital is generally
required.
- surgical repair
Your child's coarctation of the aorta may be
repaired surgically in an operating room. The
surgical repair is performed under general anesthesia.
The narrowed area is either surgically removed,
or made larger with the help of surrounding
structures or a patch.
Some
infants will be very sick, requiring care in the
intensive care unit (ICU) prior to the procedure,
and could possibly even need emergency repair
of the coarctation. Others, who are exhibiting
few symptoms, will have the repair scheduled on
a less urgent basis.
After
surgery, infants will return to the intensive
care unit (ICU) to be closely monitored during
recovery.
While
your child is in the ICU, special equipment will
be used to help him/her recover, and may include
the following:
- ventilator -
a machine that helps your child breathe while
he/she is under anesthesia during the operation.
A small, plastic tube is guided into the windpipe
and attached to the ventilator, which breathes
for your child while he/she is too sleepy to
breathe effectively on his/her own. Many children
remain on the ventilator for a while after surgery
so they can rest.
- intravenous (IV) catheters
- small, plastic tubes inserted
through the skin into blood vessels to provide
IV fluids and important medicines that help
your child recover from the operation.
- arterial line -
a specialized IV placed in the wrist, or other
area of the body where a pulse can be felt,
that measures blood pressure continuously during
surgery and while your child is in the ICU.
- nasogastric (NG) tube
- a small, flexible tube that keeps
the stomach drained of acid and gas bubbles
that may build up during surgery.
- urinary catheter -
a small, flexible tube that allows urine to
drain out of the bladder and accurately measures
how much urine the body makes, which helps determine
how well the heart is functioning. After surgery,
the heart will be a little weaker than it was
before, and, therefore, the body may start to
hold onto fluid, causing swelling and puffiness.
Diuretics may be given to help the kidneys to
remove excess fluid from the body.
- chest tube -
a drainage tube will be inserted to keep the
chest free of blood that would otherwise accumulate
after the incision is closed. Bleeding may occur
for several hours, or even a few days after
surgery.
- heart monitor -
a machine that constantly displays a picture
of your child's heart rhythm, and monitors heart
rate, arterial blood pressure, and other values.
Your
child may need other equipment not mentioned here
to provide support while in the ICU, or afterwards.
The hospital staff will explain all of the necessary
equipment to you.
Your
child will be kept as comfortable as possible
with several different medications; some which
relieve pain, and some which relieve anxiety.
The staff will also be asking for your input as
to how best to soothe and comfort your child.
After
discharged from the ICU, your child will recuperate
on another hospital unit for a few days before
going home. You will learn how to care for your
child at home before your child is discharged.
Your child may need to take medications for a
while, and these will be explained to you. The
staff will give you instructions regarding medications,
activity limitations, and follow-up appointments
before your child is discharged.
Most
children who have had a coarctation of the aorta
surgical repair will live healthy lives. Activity
levels, appetite, and growth should eventually
return to normal.
Your
child's cardiologist may recommend that antibiotics
be given to prevent bacterial endocarditis after
discharge from the hospital.
As the
child grows, the aorta may once again become narrow
on occasion. If this happens, a balloon procedure
or operation may be necessary to repair the coarctation.
Evaluation with magnetic resonance imaging (MRI)
and/or magnetic resonance angiography (MRA) is
generally recommended. If an aortic aneurysm or
dissection is suspected, computed tomography (CT
scan) may be performed.
Blood
pressure management is very important, and medications
may be prescribed to help with blood pressure
control.
Regular
follow-up care at a center offering pediatric
or adult congenital cardiac care should continue
throughout the individual’s lifespan.
Consult
your child's physician regarding the specific
outlook for your child.
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