Coarctation of the Aorta (CoA)

In the coarctation of the aorta, the large artery carrying blood to the body (the aorta) narrows close to where it emerges from the heart, usually just after the arch. Coarctation of the aorta (CoA) affects 3 of every 10,000 births and accounts for 5% to 7% of all congenital heart defects, making it relatively common.

This congenital heart defect can cause heart damage, high blood pressure in your arms and head, and low blood pressure in your legs. In some cases, the coarctation is so severe it completely blocks blood flow to the lower part of the body and is called an “interrupted aortic arch.”

Healthy heart function

In a healthy heart, the left side of the heart pumps oxygenated blood from the lungs into a large artery called the aorta. The aorta branches out throughout the body to supply blood to the entire body.

The defect

In coarctation of the heart, the aorta narrows close to where it emerges from the heart. It usually constricts on the downward side of the aortic arch, after the branches that supply blood to the head and arms.

The left side of the heart must pump harder to get blood past the constricted part of the artery. The head and arms generally get adequate or high blood flow, while the lower body does not receive enough blood flow.

CoA symptoms

Symptoms are not usually present in a newborn, but they can appear within a week or at any age after that. If the obstruction is small enough, it may never cause symptoms.

Early symptoms of a CoA in infants include:

• Pale skin.
• Irritability.
• Acidosis.
• Excessive sweating.
• High blood pressure.
• Breathing difficulties.

An infant with severe coarctation of the aorta may go into shock and die without prompt medical care. In children and teenagers, high blood pressure is usually the first symptom.

In adults, high blood pressure in the heart is the primary symptom, leading to thickening of the muscle on the left side of the heart and possibly causing damage to the heart over time.

Adults may also have:

• Headaches.
• Kidney problems.
• Weakness in the legs.
• Frequent miscarriages.

CoA Causes

Although the exact reason coarctation of the aorta develops is not known, there is a higher incidence in children with chromosomal defects, such as Jacobsen syndrome or Turner syndrome. It may also be associated with other congenital heart defects, especially aortic valve abnormalities.

CoA might occur shortly after birth if tissue builds up in the aorta as the ductus arteriosus closes.

A fetus does not need its lungs to get oxygen into the blood. The ductus arteriosus is a small hole between the aorta and the artery leading to the lungs that allows blood to skip the lungs in a fetus. This hole closes within the first week after birth to allow normal blood flow to the lungs. If tissue builds up in this area while it is closing, this may cause a narrowing – a coarctation of the aorta.

CoA diagnosis

If diagnosed before birth, your doctor may be able to intervene before the ductus arteriosus can close, possibly preventing the coarctation. However, due to the differences in blood flow before birth, doctors diagnose CoA in fewer than 1 in 4 babies before birth.

About 30% of newborns are discharged from the hospital without a diagnosis. Because collateral circulation can develop from surrounding arteries to help the aorta supply blood to the lower extremities, an infant can live with coarctation of the aorta for a while without showing any symptoms.

Your doctor may suspect a CoA only after hearing a heart murmur or measuring high blood pressure in your child.

Sometimes CoA is not diagnosed until adulthood. High blood pressure is usually the first symptom. Adults may also complain of headaches or pain in their legs during strenuous activities. Your doctor may notice a decreased pulse in the legs and feet or differences in blood pressure between the arms and legs.

If a coarctation of the aorta is suspected, your doctor may order tests to confirm the diagnosis, including:

• A chest x-ray is helpful for adults.
• Transthoracic echocardiology is the gold standard diagnostic tool for infants and children.
• A CT scan can present a better view of the coarctation.
• An MRI can visualize any collateral blood flow.

CoA treatment

Treatment depends on the person’s age, size, and the specific anatomy of the heart and aorta.

An interventional procedure or surgery to dilate (expand) the artery may be necessary at any age, especially if the blood pressure in the upper and lower extremities is unequal and abnormal. If you or your child need surgery, your doctor can help you decide which is best for you.

Sometimes surgery is unnecessary, and a doctor can repair a coarctation with transcatheter balloon angioplasty. A doctor inserts a catheter with an attached balloon into their patient’s bloodstream and through the narrowed portion of the aorta. Once at the site, the doctor inflates the balloon to open the artery, and removes the catheter and balloon. More than one of these procedures may be necessary if recoarctation occurs (the artery becomes narrow again) or an aneurysm forms.

The doctor might recommend an endovascular stent placement. Here, the doctor inserts a tiny tube called a stent into the narrowed aorta during a procedure performed like transcatheter balloon angioplasty.

Talk to your doctor about which treatment is right for you or your child.

Your doctor will probably prescribe medicine to control high blood pressure even after the procedure. You will need to see your doctor at least once a year to be monitored for high blood pressure, recoarctation, aneurysms, or other complications.

Complications

Without treatment, an adult may develop complications such as:

• Congestive heart failure, where a weakness in the heart leads to a buildup of fluid in the lungs and surrounding tissue.
• Aortic rupture, where the main artery in the body suffers a breakage.
• Bacterial endocarditis, which is a bacterial infection of the lining of the heart.
• Intracranial hemorrhage, which is bleeding from a ruptured blood vessel inside the skull (cranium).

After a medical procedure or surgery to open the constricted artery, you should still see a cardiologist regularly to check for complications, including:

• Aneurysms.
• Recoarctation.
• High blood pressure.
• Coronary artery disease.
• Enlarged left side of the heart.

CoA management

Symptoms of recoarctation are not always apparent after a repair, so frequent cardiovascular checkups are crucial to check for recoarctation, aneurysms, coronary artery disease, or high blood pressure.

If you or your child do not have high blood pressure or other symptoms after coarctation repair, you may be able to participate in any activity you choose. Talk to your child’s pediatric cardiologist about what activities you or your child can participate in safely.

Most activities are allowed and even encouraged, but your doctor might recommend that you avoid activities that involve heavy weightlifting (isometric exercises).

You or your child may need antibiotics before some dental procedures or surgeries to prevent endocarditis (a heart infection).

Talk to your doctor if you have CoA and are pregnant or plan to become pregnant.