Aortic Coarctation

What is coarctation of the aorta? Coarctation of the aorta is a congenital (present at birth) heart defect. It’s also called aortic coarctation (pronounced “ay-or-tuhk” “koh-ark-TEY-shun”). This defect affects your baby’s aorta, which is the largest artery in their body. It carries oxygen-rich blood from your baby’s heart to the rest of their body. If your baby has aortic coarctation, one part of their aorta is narrower than it should be. Picture a long balloon that’s used to make balloon animals for kids. You twist the balloon at one point to begin forming a shape. This causes the balloon to be pinched inward at that point. The pinch in the middle of the balloon is similar to what an aortic coarctation looks like. That pinched point might be very narrow and cause severe symptoms soon after birth. Or it might be narrower than normal but wide enough to let blood pass through. In that case, symptoms might not appear until later in childhood or adolescence. Symptoms such as hypertension (high blood pressure) may lead to detection of aortic coarctation. Babies who have coarctation of the aorta may also have other heart problems, including: Aortic valve stenosis. Aortic arch hypoplasia (narrowing). Atrial septal defect (ASD). Bicuspid aortic valve. Hypoplastic left heart syndrome. Mitral valve stenosis. Ventricular septal defect (VSD). Aortic coarctation needs treatment to prevent serious complications. Once a diagnosis of aortic coarctation is made, either surgical repair or balloon angioplasty should be performed.

How common is coarctation of the aorta? About 4 in 10,000 babies in the U.S. have coarctation of the aorta. Each year, about 2,200 babies are born with the condition. Of all babies born with some form of congenital heart disease, about 7 in 100 have aortic coarctation.

How does coarctation of the aorta affect my baby’s body? Coarctation of the aorta prevents blood from flowing normally throughout your baby’s body. The narrowing causes the main pumping chamber of your baby’s heart (left ventricle) to pump harder than normal. This puts a lot of stress and strain on their left ventricle. In cases where the narrowing is severe, not enough blood will get to their body and their brain, which can cause shock and even death. In milder cases, this extra strain can cause your baby’s heart muscle to get thicker (hypertrophy). Coarctation also causes higher blood pressure in your baby’s upper body, and lower blood pressure in their lower body. Your baby may have reduced blood flow to their kidneys, liver and other organs in their belly.

What are the symptoms of coarctation of the aorta?

The symptoms of aortic coarctation depend on how narrow the aorta has become. Some infants have no symptoms because the coarctation (narrowing) is very mild. But symptoms can appear within the first two weeks of birth if the coarctation is moderate or severe and the ductus arteriosus (a special fetal blood vessel) closes.

Symptoms of aortic coarctation in infants

Symptoms in infants include:

- Fast pulse.

- Fatigue.

- Gray or pale skin.

- Heavy sweating.

- Irritability.

- Rapid or labored breathing.

- Trouble breathing.

- Trouble with feeding.

- Severe coarctation in infants can lead to shock and even death if not recognized and treated promptly.

Symptoms of aortic coarctation in children

Most children don’t have any symptoms. They’re usually diagnosed after their provider notices they have high blood pressure.

Some children may have symptoms if their blood pressure is too high in their upper body or too low in their lower body. These include:

- Headaches.

- Nosebleeds.

- Leg pain during exercise.

- Symptoms of aortic coarctation in adults

Symptoms in adults are usually due to recoarctation of the aorta. This is aortic narrowing that returns sometime after a previous repair. Symptoms may include:

- Headaches.

- Kidney problems.

- Frequent miscarriages.

- Lack of energy when using your legs.

But these symptoms are linked with many other health issues in adults. So, having these symptoms doesn’t mean you have aortic coarctation. Call a healthcare provider to discuss any symptoms you have. They’ll give you a physical exam and run tests to diagnose what’s wrong.

What causes coarctation of the aorta?

The exact cause of coarctation of the aorta isn’t fully known. However, congenital heart defects are often caused by genetic changes that happen before birth. Babies with Turner syndrome have a higher risk of aortic coarctation and other defects that affect the left side of their heart.

Sometimes, environmental factors play a role in causing heart defects, too. These are factors related to the birthing parent. They include:

- Having diabetes.

- Being infected with rubella while pregnant.

- Using recreational drugs, especially cocaine.

- Using certain prescription medications, including anti-seizure drugs.

- Being over age 35.

- The role of the ductus arteriosus

The ductus arteriosus may cause coarctation of the aorta. The ductus arteriosus is a small artery that connects the fetal aorta and pulmonary artery. It helps your fetus get enough oxygen-rich blood during gestation when their lungs aren’t working yet.

Once your baby is born, their lungs start working. That means they don’t need the ductus arteriosus anymore. So, it usually closes up within a few days of birth. But when it closes, something may go wrong. Some tissue from the ductus arteriosus may blend in with tissue from their aorta. When this tissue tightens to close up the ductus arteriosus, it may narrow their aorta as well and lead to coarctation.

What is the most common site of coarctation of the aorta?

Coarctation of the aorta usually occurs in your baby’s descending aorta near their ductus arteriosus. But it can also happen in other parts of their aorta. These include other areas of the aortic arch or further down in your baby’s chest or belly.

Your baby’s aorta is a long, curved blood vessel that arches upward from the top of their heart and then curves down through their chest and belly. It’s shaped like a walking cane with a round handle. The “handle” curves upward (ascending aorta) and then downward (descending aorta). The top of that curve is called the aortic arch.

The location of aortic coarctation matters because it affects your baby’s symptoms. You can think of your baby’s aorta like a main road that has lots of intersections. At each intersection, another artery or group of arteries connects with the aorta and carries blood in a different direction.

Aortic coarctation often occurs between two major intersections. The first is where arteries branch off to the upper body. The second is where arteries branch off to the lower body. So, blood leaves your baby’s heart and travels along just fine. It reaches the first intersection and easily flows into the arteries that lead to your baby’s upper body. Meanwhile, some blood keeps moving along in their aorta. And soon it runs into trouble.

It’s like when construction forces a five-lane highway down to one lane. Only so many cars can pass through. It's the same with your baby’s aorta. That pinched, narrowed part can only let a little blood pass through. So, it’s harder for blood to reach the second intersection, where arteries carry blood to your baby’s lower body. The coarctation slows down blood flow in those arteries.

This is why the blood pressure in your baby’s arms and upper body will be high. But the blood pressure in their lower body and legs will be low. This blood pressure difference is a red flag that leads to an aortic coarctation diagnosis.