Overriding Aorta

What is an overriding aorta?

An overriding aorta is a heart condition you’re born with in which your aorta is in the wrong place. Instead of sitting over your heart’s left side, your aorta is above a ventricular septal defect or damaged wall between the left and right ventricles.

Overriding aorta is one of the four features that make up the congenital (from birth) heart problem called tetralogy of Fallot. Your aorta is supposed to be above the left side of your heart so it can take oxygen-rich blood to your body. Instead, an overriding aorta is above where a dividing wall between your left and right ventricles should be. The hole in that wall, or ventricular septal defect, is another problem of tetralogy of Fallot. When the aorta is above the ventricular septal defect, blood without oxygen can get into the aorta. This means that oxygen is missing from some of the blood your aorta is sending to your body.

In tetralogy of Fallot, blood without oxygen is able to get to the part of the heart that’s only supposed to handle oxygen-rich blood. It would be like not having a wall between the smoking and nonsmoking sections of a restaurant. Without a wall, the smoke freely goes from one section to another.

The other two abnormalities in tetralogy of Fallot are pulmonary artery and valve narrowing and right ventricular hypertrophy (thickened muscle).

Who does an overriding aorta affect?

Infants who are born male tend to have tetralogy of Fallot more often than infants who are born female. Also, those with a chromosome problem (like Down syndrome) sometimes have tetralogy of Fallot.

An overriding aorta can also happen in babies with other rare conditions, such as Apert syndrome, Irons Bhan syndrome, Steinfeld syndrome, Williams syndrome, Aortic arch anomaly-peculiar facies-intellectual disability syndrome and Fallot complex with severe mental and growth retardation.

How common is an overriding aorta?

About 1% of babies have a heart abnormality at birth. Out of that number, 10% (or an estimated one in 3,000 babies) have tetralogy of Fallot, which includes an overriding aorta.

What are the symptoms?

Some people with tetralogy of Fallot can have bad symptoms while others have mild symptoms, depending on how well blood can flow through their heart. Without treatment, symptoms can get worse.

Mild symptoms include:

• Having blue-tinted skin.
• Tiring easily.
• Having difficulty breathing.
• Having a minimal appetite.

When their oxygen level drops quickly, a baby with tetralogy of Fallot can have “tet spells” that last minutes or hours.

Severe symptoms from tet spells include:

• Having skin that looks blue.
• Feeling very tired.
• Losing consciousness.
• Having convulsions.
• Having a hard time breathing.
• Going limp.

After a tet spell, a baby might sleep for a long time.

Babies with tetralogy of Fallot may also have trouble eating, gaining weight or developing.

What causes an overriding aorta?

Sometimes, for unknown reasons, a baby’s heart doesn’t develop correctly before birth. About 25% of babies who have tetralogy of Fallot (which includes overriding aorta) are born with problems that affect other parts of their bodies as well.

How is an overriding aorta diagnosed?

Your provider will check your newborn baby for heart abnormalities. They can put sensors on your baby’s feet or hands to see if enough oxygen is present in their blood. A shortage of oxygen can be a sign of a heart problem.

When your provider listens to your baby’s heart, they’ll probably hear a murmur if overriding aorta is present.

What tests will be done to diagnose an overriding aorta?

Tests to check for an overriding aorta include:

• Echocardiogram.
• Electrocardiogram (EKG).
• Chest X-ray.
• Heart computed tomography (CT).
• Cardiac catheterization.
• Blood test.

How is an overriding aorta treated?

Your provider can fix tetralogy of Fallot with surgery before your baby is 6 months old. Fixing the ventricular septal defect and pulmonary valve issue takes care of the other two problems, including the overriding aorta. Providers have been doing open-heart surgery to fix tetralogy of Fallot since the 1950s.

In some cases, a surgeon will put in a temporary shunt between a baby’s aorta (or other artery) and pulmonary artery. This improves blood flow to the lungs until a surgeon can do a complete repair.

What medications are used?

A beta-blocker can help prevent tet spells and make them milder.

Diuretics pull excess fluids out of the body to help with heart failure.

Antibiotics can prevent endocarditis, a bacterial infection in your heart.

Complications of the treatment

Because surgeons stretch the pulmonary valve when repairing tetralogy of Fallot, the valve can leak in many cases. This puts you more at risk for heart rhythm problems. The leak can get worse with time, putting more strain on your heart and causing heart failure. Years after your surgery, you could also get an enlarged aorta or a leaky tricuspid valve, both of which would require another surgery.

How to manage symptoms

Until a provider makes a surgical repair, they can help a baby’s symptoms in these ways:

• Giving heart medicines, if needed.
• Making sure your baby is taking in enough fluids.
• Keeping track of hemoglobin levels.
• Not allowing demanding exercise.

How can I reduce my risk?

While providers aren’t sure what causes heart abnormalities in newborns, researchers believe the factors below increase your risk of having a child with a heart irregularity. These risk factors include:

• You or the baby’s other parent or one of your other children has a heart problem.
• You smoke while pregnant.
• You have rubella or diabetes.
• You take certain medications in the first three months of pregnancy.

To reduce the risk of heart abnormalities, be sure to keep your medical conditions under control, avoid smoke and don’t take medicine unless it’s ok with your provider. A genetic counselor can provide guidance if you have heart irregularities in your family.

Risk factors specific to tetralogy of Fallot (including overriding aorta) include alcoholism, diabetes, rubella, a lack of nutrition or advanced age (over 40) of the person who is pregnant.

What can I expect if I have an overriding aorta?

Complications of tetralogy of Fallot (including overriding aorta) include:

• Seizures.
• Abnormal heart rhythms.
• Anemia.
• Late development.
• Blood clotting defects.
• Cardiac arrest that can be fatal.

How long does an overriding aorta last?

Since an overriding aorta is a problem you’re born with, it will be there until a surgeon fixes it. Fortunately, the surgery to repair it is successful in most people.

Outlook for an overriding aorta

More than 90% of babies who have surgery to fix tetralogy of Fallot, which includes an overriding aorta, grow to be adults with normal lives. They are living into their 70s and 80s. If they don’t have surgery, they may not live to be 20 years old. Without treatment, symptoms get worse with time.

How do I take care of myself?

Your baby will need to have regular checkups with a provider who specializes in heart care. Children with tetralogy of Fallot need quick treatment for respiratory infections. They also need antibiotics before having surgery.

As you age, new heart problems can happen, so it’s important to keep getting checkups into adulthood.

When should I see my healthcare provider?

Contact your provider if your baby has new symptoms or has skin that looks blue.

When should I go to the ER?

Call 911 if your baby is having a severe tet spell. They can give your baby oxygen and/or morphine.

What questions should I ask my doctor?

• Will I need to limit my child’s sports activity?
• How often will my baby need checkups?
• How many surgeries will my baby need?

A note from Cleveland Clinic

Surgeons have been fixing tetralogy of Fallot ― which includes the feature of an overriding aorta ― for decades, and they have great success rates. With the surgery, your baby can have a normal life. However, it’s important to keep going to regular checkups to make sure new heart problems don’t develop. If you’re waiting for your newborn to have surgery, check with your provider to be informed about any help they can provide while you’re waiting.