Coarctation of the aorta

Coarctation of the aorta

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Coarctation of the Aorta
What is Coarctation of the aorta?

When the heart is functioning normally, a large artery called the aorta 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 toward 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 toward the abdomen, carrying blood to the lower part of the body (descending aorta).

Coarctation of the aorta, a congenital (present at birth) defect, occurs when the aorta narrows or becomes pinched. 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 symptoms a child will experience, 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 6 to 8 percent of all children with congenital heart disease. Boys have the defect twice as often as girls do.

What causes coarctation of the aorta?

Coarctation of the aorta occurs due to improper development of the aorta in the first eight weeks of fetal growth.

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 by chance, with no clear reason for its development.

Why is coarctation a concern?

Coarctation of the aorta causes several problems, including the following:

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  The left ventricle has to work harder 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. This could lead to a serious condition called congestive heart failure.
  
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  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.
  
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  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.
  
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  There is a higher than average chance of developing an infection in the lining of the heart or aorta known as bacterial endocarditis.
  
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  The coronary arteries, which supply oxygen-rich (red) blood to the heart muscle, may narrow in response to elevated pressure.
  
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  The blood pressure in the pulmonary artery may rise above normal levels, a condition called pulmonary hypertension.
  

What are the symptoms of coarctation of the aorta? 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. Each child may experience symptoms differently. Symptoms may include:

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  irritability
  
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  pale skin
  
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  sweating
  
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  heavy and/or rapid breathing
  
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  poor feeding
  
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  poor weight gain
  

Mild narrowing may not cause symptoms. 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.
What are the treatments for coarctation of the aorta?

Specific treatment for coarctation of the aorta will be determined by your child's physician based on:

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  your child's age, overall health and medical history
  
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  extent of the disease
  
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  your child's tolerance for specific medications, procedures or therapies
  
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  how your child's doctor expects the condition to progress
  
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  your opinion or preference
  

Coarctation of the aorta is treated with repair of the narrowed vessel. Your child's coarctation of the aorta may be repaired through a cardiac catheterization procedure or through surgery in an operating room:

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  Cardiac Catheterization — 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.
  

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  Surgical Repair — The surgical repair of aortic coarctation is done through an incision on the left chest below the armpit. The ribs are spread, the lung pushed aside, and the aorta exposed near the heart. The aorta is clamped on either side of the narrowing and the narrow segment with the adjacent ductus arteriosus is cut out. The two ends of aorta are then sewn together, clamps are removed, and flow through the aorta is reestablished.
  

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.

What is the long-term outlook after coarctation of the aorta surgical repair? 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.

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.

Your child's cardiologist may recommend that antibiotics be given to prevent bacterial endocarditis after discharge from the hospital.


Source: Children’s Hospital, Boston Cardiology Website, Accessible at:

http://www.childrenshospital.org/az/Site520/printerfriendlypageS520P0.html