A congenital (present at birth) heart defect in which the aorta sits above a ventricular septal defect is called an overriding aorta. In normal circumstances, the aorta is located above the left side of the heart. Furthermore, there is a vital wall between the ventricles, but it has a hole in it. As a result, the blood with and without oxygen can mix.
In other words, an overriding aorta occurs when the aorta is located in the wrong place. Moreover, this is one of the 4 features that a congenital heart disease consists of. It is called the tetralogy of Fallot, and it also causes a hole in the wall that separates the left and right ventricles (also known as a ventricular septal defect). In people with an overriding aorta, the blood without oxygen may enter the aorta. It means the oxygen is missing from some of the blood that goes throughout the body.
Generally, this congenital heart defect causes blood without oxygen to mix with oxygen-rich blood. It is very similar to a restaurant that does not have a wall between smoking and nonsmoking areas. In this case, the smoke can travel from one section to another. In addition, the tetralogy of Fallot also causes the pulmonary artery and valve to become narrower and right ventricular hypertrophy (thickened muscle).
Approximately 1% of babies are born with heart abnormalities. According to some research, about 3,000 babies have tetralogy of Fallot (including an overriding aorta).
Symptoms
The symptoms caused by tetralogy of Fallot range from mild to severe. Check some of them below:
Mild Symptoms
- Bluish skin
- Tiredness
- Breathing problems
- Appetite changes
Severe Symptoms
Usually, the following symptoms appear in a baby with tetralogy of Fallot when oxygen levels in the blood suddenly drop. These include:
- Skin color changes
- Fatigue (extreme tiredness)
- Convulsions
- Loss of consciousness
- Dyspnea (shortness of breath)
Those who are born with tetralogy of Fallot may also have problems with eating, gaining weight, or developing.
Causes and Risk Factors
In some cases, tetralogy of Fallot occurs without a known reason, in which the baby’s heart does not develop properly during pregnancy. However, approximately 25% of babies who are born with tetralogy of Fallot also have other problems that negatively affect other parts of the body.
While it is not possible to determine what causes tetralogy of Fallot, physicians have identified some factors that could increase your risk of developing it. Examples include:
- Drinking alcohol or smoking during pregnancy
- Down syndrome
- DiGeorge syndrome
- You become pregnant after 35 years old
- Poor diet during pregnancy
- A family history of tetralogy of Fallot
- Certain infections (such as rubella, also called German measles)
What Are The Potential Complications of Overriding Aorta?
Babies who are born with this congenital heart defect (including an overriding aorta) may also experience some complications, especially if they do not get treatment. For example:
- Blood clotting defects
- Cardiac arrest (this is a medical emergency and without immediate treatment can be fatal)
- Anemia (low red blood cell count)
- Arrhythmia (irregular heart rhythm)
- Delayed development
- Seizures
- Bacterial endocarditis
- Right or left ventricular dysfunction
- Chronic pulmonary regurgitation
The previous list does not contain a full list of overriding aorta complications. In any case, doctors may recommend some tips that will reduce the risk of developing them.
How to Prevent Overriding Aorta?
In general, there is no way to prevent congenital heart defects (including an overriding aorta present in babies with tetralogy of Fallot). However, doctors may recommend some tips for the biological mother to reduce the risk. These include:
- Discuss with your doctor about taking medicines to prevent rubella (German measles) in the first 3 months of pregnancy
- Quit smoking – If you have problems with smoking cessation, it is advised to discuss it with your doctor.
- Avoid alcoholic beverages during pregnancy, especially if you have a family history of tetralogy of Fallot
- Manage existing health problems
- Dietary changes – It is very important to get enough nutrients and vitamins during pregnancy. Otherwise, some parts of the baby’s body may not develop properly.
Diagnosis
When this congenital heart defect is suspected, doctors will check the baby’s heart for abnormalities. They may put sensors on the feet or hands to determine if the baby has enough oxygen in the blood. Reduced oxygen levels may indicate a heart problem. Check below some tests often done to confirm or rule out an overriding aorta:
- Electrocardiogram (ECG or EKG) – This is a quick and painless test used to measure the electrical activity of the heart.
- Chest X-ray
- Heart CT (computed tomography)
- Echocardiogram
- Cardiac catheterization
- Blood tests
Treatment
Usually, healthcare professionals are able to fix the tetralogy of Fallot in the first 6 months of life. They often perform surgery to fix the ventricular septal defect and pulmonary valve problems, which thus takes care of the other 2 problems (including the overriding aorta). The interventions that are used to treat this congenital heart defect have been used since the 1950s. Sometimes, surgeons may place a shunt between the aorta or other artery and the pulmonary artery, which helps improve blood flow to the lungs until the repair is done. Moreover, physicians may also prescribe some medications to prevent tet spells or make them milder. These include:
- Beta-blockers
- Diuretics (to remove excess fluid from the body)
- Antibiotics (to prevent bacterial infections such as endocarditis)
Furthermore, the previous treatment options may cause some adverse reactions. These include valve leaks, an increased risk of arrhythmia, heart failure, enlarged aorta, tricuspid valve leakage, and others.
How to Manage Symptoms?
The following tips may help take care of the baby while the surgeon repairs heart problems. For example:
- Heart medications
- Avoid demanding exercise
- Monitor hemoglobin levels
- Make sure your baby is drinking enough fluids
Frequently Asked Questions
How long does an overriding aorta last?
This congenital heart defect is present until the surgeons fix it. However, most people are successfully treated with surgery.
When should I go to the ER?
Call 911 or go to the nearest emergency room (ER) if your child has a severe tet spell and experiences severe symptoms (such as shortness of breath).
Who does an overriding aorta affect?
In general, tetralogy of Fallot affects males more commonly than females. Those who have problems with chromosomes (such as Down syndrome) also develop this congenital heart defect. Furthermore, there are other rare health conditions that also increase the risk of developing an overriding aorta. These include Irons Bhan syndrome, Apert syndrome, Steinfeld syndrome, Williams syndrome, and Aortic arch anomaly-peculiar facies-intellectual disability syndrome. If you have additional questions, ask your healthcare provider.
