What is tetralogy of Fallot?
Tetralogy of Fallot is a rare condition caused by a combination of four heart defects that are present at birth. These defects, which affect the structure of the heart, cause oxygen-poor blood to flow out of the heart and to the rest of the body. Infants and children with tetralogy of Fallot usually have blue-tinged skin because their blood doesn’t carry enough oxygen.
Tetralogy of Fallot is often diagnosed during infancy or soon after. However, tetralogy of Fallot might not be detected until later in life, depending on the severity of the defects and symptoms. With early diagnosis followed by appropriate surgical treatment, most children who have tetralogy of Fallot live relatively normal lives, though they’ll need regular medical care and might have restrictions on exercise.
How common is tetralogy of Fallot?
Tetralogy of Fallot is relatively rare, occurring in about 5 of every 10,000 births. Please discuss with your doctor for further information.
What are the symptoms of tetralogy of Fallot?
The common symptoms of tetralogy of Fallot are:
- A bluish coloration of the skin caused by blood low in oxygen (cyanosis)
- Shortness of breath and rapid breathing, especially during feeding or exercise
- Loss of consciousness (fainting)
- Clubbing of fingers and toes — an abnormal, rounded shape of the nail bed
- Poor weight gain
- Tiring easily during play or exercise
- Prolonged crying
- A heart murmur
Tetralogy of Fallot symptoms vary, depending on the extent of obstruction of blood flow out of the right ventricle and into the lungs.
Sometimes, babies who have tetralogy of Fallot will suddenly develop deep blue skin, nails and lips after crying or feeding, or when agitated. These episodes are called tet spells and are caused by a rapid drop in the amount of oxygen in the blood. Tet spells are most common in young infants, around 2 to 4 months old. Toddlers or older children might instinctively squat when they’re short of breath. Squatting increases blood flow to the lungs.
There may be some symptoms not listed above. If you have any concerns about a symptom, please consult your doctor.
When should I see my doctor?
You should contact your doctor if you have any of the following:
- Difficulty breathing
- Bluish discoloration of the skin
- Passing out or seizures
- Unusual irritability
If you have any signs or symptoms listed above or have any questions, please consult with your doctor. Everyone’s body acts differently. It is always best to discuss with your doctor what is best for your situation.
What causes tetralogy of Fallot?
Tetralogy of Fallot occurs during fetal growth, when the baby’s heart is developing. While factors such as poor maternal nutrition, viral illness or genetic disorders might increase the risk of this condition, in most cases the cause of tetralogy of Fallot is unknown.
The four abnormalities that make up the tetralogy of Fallot include:
- Pulmonary valve stenosis. Pulmonary valve stenosis is a narrowing of the pulmonary valve — the valve that separates the lower right chamber of the heart (right ventricle) from the main blood vessel leading to the lungs (pulmonary artery). Narrowing (constriction) of the pulmonary valve reduces blood flow to the lungs. The narrowing might also affect the muscle beneath the pulmonary valve.
- Ventricular septal defect. A ventricular septal defect is a hole in the wall that separates the two lower chambers of the heart — the left and right ventricle. The hole allows deoxygenated blood in the right ventricle — blood that has circulated through the body and is returning to the lungs to replenish its oxygen supply — to flow into the left ventricle and mix with oxygenated blood fresh from the lungs. Blood from the left ventricle also flows back to the right ventricle in an inefficient manner. This ability for blood to flow through the ventricular septal defect reduces the supply of oxygenated blood to the body and eventually can weaken the heart.
- Overriding aorta. Normally the aorta — the main artery leading out to the body — branches off the left ventricle. In tetralogy of Fallot, the aorta is shifted slightly to the right and lies directly above the ventricular septal defect. In this position the aorta receives blood from both the right and left ventricles, mixing the oxygen-poor blood from the right ventricle with the oxygen-rich blood from the left ventricle.
- Right ventricular hypertrophy. When the heart’s pumping action is overworked, it causes the muscular wall of the right ventricle to thicken. Over time this might cause the heart to stiffen, become weak and eventually fail.
Some babies who have tetralogy of Fallot may have other heart defects, such as a hole between their heart’s upper chambers (atrial septal defect).
What increases my risk for tetralogy of Fallot?
There are many risk factors for tetralogy of Fallot, such as:
- A viral illness during pregnancy, such as rubella (German measles)
- Alcoholism during pregnancy
- Poor nutrition during pregnancy
- A mother older than age 40
- A parent who has tetralogy of Fallot
- The presence of Down syndrome or DiGeorge syndrome
Diagnosis & treatment
The information provided is not a substitute for any medical advice. ALWAYS consult with your doctor for more information.
How is tetralogy of Fallot diagnosed?
After your baby is born, your baby’s doctor might suspect tetralogy of Fallot if your baby has blue-tinged skin or if a heart murmur — an abnormal whooshing sound caused by turbulent blood flow — is heard in your baby’s chest. Your baby’s cardiologist will conduct a physical examination and use several tests to confirm the diagnosis.
Tests may include:
- Echocardiograms use high-pitched sound waves to produce an image of the heart. Sound waves bounce off your baby’s heart and produce moving images that can be viewed on a video screen. This test is generally used to diagnose tetralogy of Fallot. It allows your baby’s doctor to determine if there is a ventricular septal defect and where it’s located, if the structure of the pulmonary valve and pulmonary artery is normal, if the right ventricle is functioning properly, and if the aorta is positioned properly. This test can also help your baby’s doctors to plan treatment for your baby’s condition.
- An electrocardiogram records the electrical activity in the heart each time it contracts. During this procedure, patches with wires (electrodes) are placed on your baby’s chest, wrists and ankles. The electrodes measure electrical activity, which is recorded on paper. This test helps determine if your baby’s right ventricle is enlarged (right ventricular hypertrophy), if your baby’s right atrium is enlarged and if the heart rhythm is regular.
- Chest X-ray. A chest X-ray can show the structure of your baby’s heart and lungs. A common sign of tetralogy of Fallot on an X-ray is a “boot-shaped” heart, because the right ventricle is enlarged.
- Oxygen level measurement (pulse oximetry). This test uses a small sensor that can be placed on a finger or toe to measure the amount of oxygen in your baby’s blood.
- Cardiac catheterization. Doctors may use this test to evaluate the structure of the heart and plan surgical treatment. During this procedure, your baby’s doctor inserts a thin, flexible tube (catheter) into an artery or vein in your baby’s arm, groin or neck and threads it up to his or her heart. Your baby’s doctor injects a dye through the catheter to make your baby’s heart structures visible on X-ray pictures. Cardiac catheterization also measures pressure and oxygen levels in the chambers of the heart and in the blood vessels.
How is tetralogy of Fallot treated?
Surgery is the only effective treatment for tetralogy of Fallot. Surgical options include intracardiac repair or a temporary procedure that uses a shunt. However, most babies and older children have intracardiac repair. Your child’s doctors will determine the most appropriate surgery and the timing of the surgery based on your child’s condition.
This open-heart surgery is usually done during the first year after birth. The surgeon places a patch over the ventricular septal defect to close the hole between the lower chambers of the heart (ventricles).
He or she also repairs or replaces the narrowed pulmonary valve and widens the pulmonary arteries to increase blood flow to the lungs. After intracardiac repair, the oxygen level in the blood increases and your child’s symptoms will lessen.
Occasionally babies need to undergo a temporary surgery before having intracardiac repair.
If your baby was born prematurely or has pulmonary arteries that are underdeveloped (hypoplastic), the surgeon will create a bypass (shunt) between a large artery that branches off from the aorta and the pulmonary artery.
This bypass increases blood flow to the lungs. When your child is ready for intracardiac repair, the surgeon removes the shunt during the procedure for intracardiac repair.
While most babies do well after intracardiac repair, complications are possible. Complications may include:
- Chronic pulmonary regurgitation, in which blood leaks through the pulmonary valve back into the pumping chamber (right ventricle)
- Irregular heartbeats (arrhythmias)
- Aortic root dilation, in which the ascending aorta enlarges
- Sometimes blood flow to the lungs may still be restricted after intracardiac repair. Infants, children or adults with these complications might require additional surgeries. In some cases, the pulmonary valve might need to be replaced.
Arrhythmias may be treated with medications, a procedure to treat the arrhythmias or an implantable cardioverter-defibrillator.
In addition, as with any surgery, there’s a risk of infection, unexpected bleeding or blood clots.
Complications can continue throughout childhood, adolescence and adulthood for people with tetralogy of Fallot.
After surgery your child will need lifelong care with a cardiologist trained in treating congenital heart disease, including routine follow-up appointments to make sure that the procedure was successful and to monitor for any new complications.
Your doctor may conduct a physical examination and order tests in regular follow-up appointments to evaluate and monitor your child’s condition.
The doctor might also recommend that your child limit physical activity, particularly if there’s any pulmonary valve leakage or obstruction, or arrhythmias.
Sometimes, antibiotics are recommended during dental procedures to prevent infections that might cause endocarditis — an inflammation of the lining of the heart. Antibiotics are especially important for those who have artificial valves or who’ve had repair with prosthetic material. Ask your child’s doctor what’s right for your child.
Lifestyle changes & Home remedies
What are some lifestyle changes or home remedies that can help me manage tetralogy of Fallot?
The following lifestyles and home remedies might help you cope with tetralogy of Fallot:
- Preventing infection. A child who has severe heart defects might need to take preventive antibiotics before certain dental and surgical procedures. Your child’s doctor can tell you if this is necessary. Maintaining good oral hygiene and getting regular dental checkups are excellent ways to help prevent infection.
- Exercising and play. Parents of children who have congenital heart defects often worry about the risks of rough play and vigorous activity even after successful treatment. Although some children might need to limit the amount or type of exercise, many can lead normal or near-normal lives. Decisions about exercise need to be made on a case-by-case basis, so ask your child’s doctor which activities are safe for your child.
If you have any questions, please consult with your doctor to better understand the best solution for you.
Hello Health Group does not provide medical advice, diagnosis or treatment.
Review Date: July 18, 2017 | Last Modified: December 9, 2019
- tetralogy of Fallot. http://www.mayoclinic.org/diseases-conditions/tetralogy-of-fallot/basics/definition/con-20043262. Accessed 13 Feb 2017
- tetralogy of Fallot. http://www.heart.org/HEARTORG/Conditions/CongenitalHeartDefects/AboutCongenitalHeartDefects/Tetralogy-of-Fallot_UCM_307038_Article.jsp#.WKCdizt97IU. Accessed 13 Feb 2017