Coarctation of the Aorta (page 3)

What Is Coarctation?

The aorta is the major blood vessel that carries blood away from the heart to the body. When someone has coarctation of the aorta, the aorta is narrowed at some point.

Here's how a healthy heart and aorta work: Blood that needs oxygen comes from all over the body and enters the right side of the heart, which pumps it to the lungs. The lungs fill the blood with oxygen, and this oxygen-rich blood returns from the lungs to the left side of the heart. The left side of the heart finishes up by pumping the blood out through the aorta. From the aorta, the blood travels through arteries that reach all of the body's organs and tissues, bringing them oxygen. Then the blood returns to the heart through veins and begins the cycle once again.

When part of the aorta is narrowed (this is a coarctation), that defect can affect the body's blood circulation because the left side of the heart has to work harder to pump blood through the narrowed aorta.

Sometimes the narrowing is minor and might not even cause symptoms. In other cases, the aorta is more constricted, placing a strain on the heart's left ventricle (the chamber that pumps blood to the aorta and out to the body).

A coarctation can occur anywhere in the aorta, but most often is found after the point where the arteries that carry blood to the upper body and head branch off from the aorta.

Causes

Coarctation of the aorta (or COA) is a congenital defect, meaning that someone is born with it. About 1 in 100 children is born with a heart problem, and coarctation represents about 8% of those cases. Doctors don't know for sure why certain people are born with this narrowing of the aorta.

Coarctation occurs more commonly in boys, but is often seen in girls with Turner syndrome, in which one of two X chromosomes is incomplete or missing. COA may occur with other birth defects or congenital heart conditions, such as a ventricular septal defect (a hole in the wall between the heart's left and right ventricles).

Coarctation also can be associated with other structures abnormalities of the left side of the heart. A common association is a bicuspid aortic valve, in which the aortic valve between the left ventricle and aorta has two leaflets instead of the normal three.

Most people with COA are diagnosed as babies or young children, although some aren't diagnosed until they're teens or even adults. Usually, in this case, the narrowing in the aorta is not severe enough to cause serious symptoms while the person is very young. But even those who do not have major symptoms usually need to be treated because the coarctation can eventually cause problems. COA will not go away on its own.

Signs and Symptoms

Often an abnormal blood pressure test is the first detected sign of COA. During a physical exam, a doctor may find that a child with a coarctation has a higher blood pressure in the arms than in the legs, and also might hear a heart murmur or notice that the pulse in the groin is weak or difficult to feel. Any person diagnosed with high blood pressure should be checked for coarctation of the aorta.

Kids who have COA often do not have any symptoms and have only mild signs that are discovered by accident during a regular visit to the doctor. A child who does have symptoms may experience some or all of these:

• cold legs and feet
• shortness of breath, especially when exercising
• chest pain

Diagnosis and Treatment

Doctors may refer a child with the signs or symptoms of COA to a pediatric cardiologist (a doctor who specializes in diagnosing and treating heart disease in kids and teens). The cardiologist will listen to the heart, feel the pulses, and check blood pressure.

The doctor probably will order an echocardiogram, a test that uses sound waves to create a picture of the heart and its circulation. Other tests that produce images of the heart, such as a chest X-ray, a magnetic resonance imaging (MRI) test, or a computerized tomography (CT) scan, also may be used to help the cardiologist look for a narrowing of the aorta.

A severe coarctation is usually diagnosed shortly after birth and repaired by surgery immediately. In an older patient, doctors often recommend that COA be treated quickly, since it can cause persistent high blood pressure and cause heart enlargement. The defect can also cause dissection or rupture of the aorta, which can be fatal in many people by the age of 40.

Coarctation of the aorta can be repaired either by surgery or other procedures. Different types of surgery can repair a narrowing of the aorta, but one of the most common ways to fix COA is to remove the narrow section and reconnect the two ends of the aorta.

In some cases, doctors may do a procedure known as balloon dilation or balloon angioplasty. They insert a tiny balloon into a blood vessel in the leg and use a very thin wire to thread it up to the aorta, across the narrow area. When the doctor inflates the balloon, the narrow area is expanded. After the area has been widened, the balloon is removed. The cardiologist also may implant a device called a stent to keep the area open after the procedure.