Tetralogy of Fallot in Children: Symptoms, Causes and Treatment

Introduction

As a new parent, it is only natural that you are worried about your child and their health. When they fall sick or hurt themselves, you rush to their side immediately. With a condition like Tetralogy of Fallot, a congenital heart defect, it may at first sound alarming to hear and with good reason. However, learning what this condition is and knowing about the various treatment options to manage this can help relieve some of the worries that you may have felt initially.

Congenital heart diseases are defects in the heart that can occur in the baby before birth. There are many types of congenital diseases. Tetralogy of Fallot is one such condition that affects the blood flow in the heart. One common sign of this condition is that a baby’s skin may appear bluish. Babies diagnosed with tetralogy of fallot usually require immediate treatment to prevent further complications.

While this can seem daunting, understanding the diagnosis and various prevention and treatment methods can help relieve the stress and anxiety around the condition. Keep reading to learn more about Tetralogy of Fallot in babies.

What is Tetralogy of Fallot?

Tetralogy of Fallot is a rare heart condition that is caused by four different but related heart defects that can occur during birth^[1]. Together, these defects can cause an increase of deoxygenated blood in the baby’s bloodstream.

Four conditions that together cause Tetralogy of Fallot are:

• A hole between the right and left ventricles, which are the two lower chambers of the heart (ventricular septal defect).
• Narrowing of the lung valve that causes reduced blood flow to the lungs (pulmonary valve stenosis).
• The aorta (the main artery) lies over the hole in the lower chambers of the heart. 
• Thickening of the lower right chamber (right ventricular hypertrophy).

Because of this, children and infants who suffer from this defect may have slightly blue-tinged skin. This is also why the Tetralogy of Fallot is a cyanotic heart defect – cyanosis refers to the blue discolouration of the skin. 

Tetralogy of Fallot is often diagnosed at infancy or soon after. However, in some cases, this condition might not be detected until the baby reaches adulthood.

How Common Is It?

Tetralogy of Fallot is shown to occur in around 3-5 out of 10,000 live births globally^[2]. While this heart defect was first identified over 120 years ago, its exact cause is yet to be known. Approximately 15% of individuals suffering from Tetralogy of Fallot have certain genetic abnormalities related to other birth defects.

How Common Is It in India?

In India, around 4 out of 1,000 babies are born with congenital heart defects. Tetralogy of Fallot accounts for 7% to 32% of these cases.

A study conducted on 819 patients who have undergone Tetralogy of Fallot repair surgery between the ages of 10, 20 and 30 years showed survival rates of 95.8%, 92.7% and 90.5%.

Children who have been diagnosed with Tetralogy of Fallot usually need to go for regular checkups with a cardiologist for the rest of their lives. They may also have some lifestyle restrictions in order to prevent complications arising in the future. In some cases, multiple surgeries may also be required to treat this cyanotic heart defect.

How Fatal Is It?

Tetralogy of Fallot can be fatal if not treated properly and quickly enough. Some complications of tetralogy of fallot include bacterial and viral heart infections, arrhythmias or irregular heartbeat issues, blood clots, heart failure and in the worst cases, death.

This is why, in most cases, corrective surgery is performed within the first year after birth to prevent complications from developing later on.

Key Takeaways

• Tetralogy of Fallot is a congenital condition caused by four heart defects.
• The Tetralogy of Fallot affects 5 out of 10000 births around the world, but the exact cause is still unknown.
• Tetralogy of Fallot is a condition that can be treated and managed when diagnosed early.

Tetralogy Of Fallot Symptoms In Infants

The signs of Tetralogy of Fallot are visible a few weeks after birth. The symptoms may also vary based on the intensity of the condition. An early diagnosis of Tetralogy of Fallot can help your child get treated in time and avoid future complications. The symptoms of tetralogy of fallot in Indian infants include:

• Passing out or seizures
• Bluish skin^[5]
• Breathlessness
• Having trouble breastfeeding or eating
• Irritability
• Heart murmur
• Fainting/Weakness
• Less stamina
• The abnormally rounded shape of nail beds

What is a Tet Spell?

Babies who have been diagnosed with tetralogy of fallot may sometimes experience sudden bluish discolouration in their skin, lips or nails. This is usually accompanied by crying, discomfort or agitation. These episodes are called tet spells (also called hypoxic spell or cyanotic spell) and they occur due to a sudden drop in blood-oxygen levels (i.e. Hypoxia). Tet spells occur more commonly in infants between the ages of 2 and 4 months.

It’s best to seek medical assistance immediately if your baby is:

• Struggling to breathe
• Turning blue
• Showing signs of weakness
• Extremely irritable, agitated or uncomfortable
• Experiencing seizures
• Dizzy or showing signs of fainting

If you notice your child is having a tet spell or is generally turning blue, a quick first aid would be to lay your child on the side and lift his/her knees up against the chest. This can temporarily help increase the blood flow to the lungs.

Key Takeaways

• Tetralogy of Fallot Symptoms can be detected within the first few weeks after birth and can differ based on the intensity of the condition.
• Some common symptoms of this condition include passing out, seizures, bluish skin, breathlessness and so on.
• Tet spells are episodes that occur when there is a sudden drop in the level of oxygen in the blood. This in turn will give rise to bluish tinged skin near the lips, skin and/or nails.

Causes of Tetralogy of Fallot

Tetralogy of Fallot in babies usually occurs in the pregnancy stage when the baby’s heart is being developed. While the actual causes of tetralogy of fallot are unknown, the condition comprises of 4 main heart defects:

1. Ventricular Septal Defect (Hole in the Heart)

• An opening or a hole is present in the wall between the two lower chambers (ventricles) of the heart on both sides.
• Due to this, oxygen-rich blood flows into the right ventricle and mixes with deoxygenated blood in the pulmonary artery, which goes to the lungs. 
• This may cause a baby to appear blue since there is not enough oxygen in the bloodstream.
• For ventricular septal defect treatment, the doctor might prescribe certain medications based on the severity of the symptoms or might recommend opting for medical procedures like surgical repair or catheter procedure.

2. Pulmonary Valve Stenosis (Narrowing of the Valve in the Lung)

• A narrowing in the opening between two chambers of the heart, specifically the right ventricle and pulmonary artery. 
• It becomes more difficult for blood to flow out of the heart into the lungs because it has to go through this smaller opening.

3. Right Ventricular Hypertrophy (Thickening of the Heart Chamber)

• The heart comprises of four chambers – two lower chambers and two upper chambers called the ventricles and atrium, respectively. 
• When the heart is overworked, the lower right ventricle wall can thicken over time causing the heart to become stiff, weaken and then eventually fail.

4. Aorta Abnormalities

• In a normal, healthy heart, the aorta is connected to the left ventricle.
• In the tetralogy of fallot, the aorta may be positioned right above the heart wall that has a hole (ventricular septal defect). 
• Due to this, the aorta receives both oxygenated and deoxygenated blood for both the left and right ventricles.
• This weakens the original function, which is to supply oxygenated blood to the rest of the body.

Risk Factors

As mentioned briefly earlier, the exact cause of tetralogy of fallot remains unknown. However, there are a few factors that can put your child at risk of developing this cyanotic heart defect. They include:

1. Having a Viral Illness During Pregnancy

A viral illness, such as rubella, during pregnancy has been associated with the Tetralogy of Fallot.^[7] If you think you have a viral infection while pregnant, it’s best to seek medical attention at the earliest. 

2. Poor Nutrition During Pregnancy

Proper diet and nutrition are necessary when pregnant to ensure a healthy pregnancy term for you and your child in order to prevent congenital heart defects like tetralogy of fallot in your baby. Therefore, if you are pregnant or are planning a pregnancy, do seek the advice of your gynaecologist for your dietary requirements throughout your pregnancy. 

3. Drinking Alcohol During Pregnancy

Drinking alcohol during pregnancy can cause problems for your unborn baby and should be avoided at all costs. 

4. An Older Mother (Above 40 Years Old)

Mothers older than 35 years old have an increased risk of conceiving babies with various birth defects, including heart conditions such as the Tetralogy of Fallot.

5. Family History of Congenital Heart Disease

If any of the parents have a history of Tetralogy of Fallot, the child may be at risk of developing the same^[8]. In such cases, it is always better to have a detailed ultrasound of the child’s heart in its early stages. If any abnormality or defect is noticed in your child, consult with your doctors and get Tetralogy of Fallot treatment at the earliest.

6. A Baby With Down syndrome or DiGeorge syndrome

Tetralogy of Fallot may develop in babies with Down’s syndrome or DiGeorge syndrome.

Key Takeaways

• Tetralogy of Fallot usually occurs during the time when the baby’s heart is being developed.
• The condition occurs when there are four defects in the heart. These defects are Ventricular Septal Defect, Pulmonary Valve Stenosis, Right Ventricular Hypertrophy and Aorta Abnormalities.
• The causes of Tetralogy of Fallot are relatively unknown but there are a few factors that may put the child at risk. Some of these factors include genetics, poor nutrition during pregnancy, alcohol consumption and so on.

Tetralogy of Fallot Diagnosis

If your doctor suspects your child may have a congenital heart defect, he/she may perform various diagnostic tests based on the symptoms your child may be showing. Some of the tests that the doctor may perform to rule out a tetralogy of fallot diagnosis include:

• Monitoring Oxygen levels: A pulse oximeter can be used to measure the Oxygen saturation of baby.
• Echocardiogram (ECG): This is a noninvasive test that emits sound waves to the heart. The echoes from these pulses are then received and displayed by a computer, enabling doctors to view the size, shape and movement of your baby’s heart valves or blood vessels. A Tetralogy of Fallot ECG may show abnormalities in heart valve and blood vessel function.
• Electrocardiogram: An electrocardiogram shows the electrical activity happening in the heart every time it beats. This helps identify the extent of right ventricular hypertrophy (the thickening of the heart chamber), enlarged heart chambers and irregular heartbeat.
• X-Ray: A Tetralogy of Fallot x-ray may show a heart larger than usual – usually in the shape of a boot. This is usually due to an enlarged right ventricle and can be a cause of grave concern if left untreated.
• Cardiac Catheterisation: This test is used to understand the structure of the baby’s heart in case surgery is required as treatment. In this procedure, a small tube called a catheter is inserted into a blood vessel in the groin and then guided carefully to the heart. This catheter contains a dye that enables the doctor to see the structure of the heart easily through an X-ray.

Can Tetralogy of Fallot Be Diagnosed Before the Baby Is Born?

During pregnancy, the baby’s heart is one of the first organs that start to develop and so tetralogy of fallot in a baby can be detected as early as 8 weeks into the pregnancy through fetal Echocardiography, which is not easily available and requires expertise^[3]. 

Preparing for a Diagnosis

An early diagnosis of a congenital heart defect like tetralogy of fallot can go a long way in managing the condition effectively in the future. During your appointment, it’s best to let your doctor know about:

• Your entire medical history and family history.
• All the signs and symptoms that your child is experiencing, no matter how small or big and even if it’s not related to heart issues.
• When your child started showing symptoms, the exact frequency and intensity.
• The medications (if any) you took during your pregnancy term, any treatment plans you were put on during pregnancy. Any medications your child has been taking since birth. 
• Any supplements, vitamins or over the counter medications you took during your pregnancy.
• Your general lifestyle habits before and during pregnancy.

What to Expect After a Diagnosis?

Tetralogy of Fallot is a condition that usually requires surgical treatment at the earliest after birth. Post diagnosis, you may be:

• Referred to a paediatric heart surgeon who may determine the right course of treatment for your child. 
• Advised to schedule regular visits with a pediatric cardiologist to monitor your child’s heart health and lower the risk of any complications.

Key Takeaways

• Some diagnostic tests that are performed to detect congenital heart defects include ECG, X-rays, Cardiac catheterisation or electrocardiogram.
• Tetralogy of Fallot can be detected as early as 8 weeks into the pregnancy.
• This condition will require surgery to be conducted within the first year after birth. Post this, a paediatric heart surgeon will direct you on the treatment that will best suit your child.

Tetralogy of Fallot Treatment

What to Expect?

If and when tetralogy of fallot is detected in your child, the doctor may suggest any of the following treatment options based on the symptoms and the severity of the condition:

• Intracardiac Repair: This Tetralogy of Fallot surgery is an open-heart procedure. This procedure involves 2 main repairs:
  • Patching over the holes between the left and right chambers (ventricles) of the heart. 
  • Repairing or replacing (depending on the condition) the pulmonary valve that has been narrowed to increase the flow of blood to the lungs.

Through this surgery, the functioning of the right ventricle is restored. Due to this, it eventually goes back to its normal thickness. The blood-oxygen level also increases.

• Temporary Shunt Surgery: This Tetralogy of Fallot surgery is a temporary measure before undergoing intracardiac repair to help increase the flow of blood to the lungs. This is usually done in premature babies or those with underdeveloped or improperly formed pulmonary arteries.

In this surgery, a temporary tube, known as a shunt, is placed between the main artery, aorta and the pulmonary artery so that oxygen-rich and deoxygenated blood can circulate between the right side of the heart and either lung. When the doctor feels your baby is ready for intracardiac repair, the shunt is then removed during the procedure.

Supportive Care After Surgery

After surgery, your child will be taken to the Paediatric Intensive Care Unit (PICU) or Cardiac Surgical Unit (CSU). Your child’s healthcare provider may:

• Continue giving antibiotics and pain medicine as a part of the management of Tetralogy of Fallot while in a critical care unit. 
• Place a breathing tube into the throat through the mouth during cardiac surgery. 
• Place a catheter in the bladder to drain urine during surgery while your child stays in a critical care unit.

Your child’s healthcare provider will monitor several parameters as part of the recovery:

• Vitals: such as breathing, blood oxygen, blood pressure, temperature, etc.
• The functioning of the heart: The doctor may use an echocardiogram to check how well blood flows through your child’s heart chambers. 

Possible complications, include: 

• A leaky pulmonary valve: If blood flow to the lungs remains obstructed after surgery, additional surgeries may be needed. Some adults with repaired Tetralogy of Fallot may also require a pulmonary valve replacement due to leaky pulmonary valve. 
• Irregular heartbeat and problems with the heart rhythm: This is common after tetralogy of fallot surgery and is usually managed by doctor-prescribed medications or implantation of a pacemaker that helps control the rhythm of the heart.
• Risk of heart infections: heart infections, especially endocarditis, is a compilation that can occur in children post tetralogy of fallot surgery. Your doctor may give your child certain medications to take before any dental or oral procedures to lower the risk of developing endocarditis.

People who have had surgery to repair tetralogy fallot usually require lifelong care with a cardiologist to monitor the functioning of the heart and for any complications that may arise. Therefore, effective management of Tetralogy of Fallot may include frequent visits to the doctor, undergoing imaging tests and other diagnostic tests to evaluate the progress of treatment and also certain lifestyle and activity restrictions to prevent worsening of the condition.

Key Takeaways

• Tetralogy of fallot treatment is prescribed depending on your child’s condition and symptoms. Those treatments may include intracardiac repair and temporary shunt surgery.
• Post the surgery, there is a lot of post-care that will need to be done. They will be taken to the PICU or the CSU where they will continue to monitor your child.
• The healthcare providers will continue to check your child’s vitals and blood flow as well as monitor for any complications that could arise post-surgery.
• Lifelong follow up with a heart specialist is mandatory.

Tips, Lifestyle Changes, Home Remedies for Expecting Mothers & Children with Tetralogy of Fallot

If you are a pregnant woman or one who is planning a pregnancy, your doctor may recommend a few lifestyle changes to help lower the risk of your baby developing tetralogy of fallot in the womb. These include:

1. Maintain Good Personal Hygiene and Protect Yourself from Illness

Being sick can lead to complications during pregnancy that may put the baby at risk. Expecting mothers need to be wary about contracting rubella (german measles), an infection that can put your child at risk of developing congenital heart disease. Here are some ways you can lower your risk:

• Maintain good personal hygiene
• Wash your hands with soap often 
• Stay away from those who may be sick
• Wash vegetables and fruits thoroughly before consuming

2. Avoid Alcohol and Smoking During Pregnancy

During pregnancy, a woman must refrain from drinking alcohol and smoking in order to protect herself and her baby from serious health problems^[4]. Heavy exposure to environmental pollutants such as cigarette smoke may increase blood pressure for both the mother and foetus, which can be dangerous for them throughout their lives. Other causes of high blood pressure include stress, lack of physical activity and being obese. 

3. Eat a Healthy Diet and Stay Active During Pregnancy

Eating a healthy diet and staying active during pregnancy is the best thing you can do for your baby. Not only do you give birth to healthier babies but it can also put both moms-to-be and their children on a better path toward long-term health.

4. Prioritise Quality Sleep and Mental Health During Pregnancy

The hormone changes, body aches and pains can all contribute to a lack of restful sleep. Pregnant women who do not get enough quality sleep may be more likely to:

• Become depressed or anxious
• Experience fatigue and daytime drowsiness
• Have slower reaction times
• Be more likely to gain excess weight and all these can impact the health of the baby

Therefore, being stress-free and enjoying your pregnancy as much as possible can go a long way in protecting your baby’s health as well. If you seem to be struggling with your mental health during pregnancy, seeking the support of your friends and family or even a qualified counsellor can help you cope with the anxieties around this stage of life.

What About My Child? How Can They Lower Their Risk?

Post-treatment, the doctor may recommend certain lifestyle changes to help effectively manage tetralogy of fallot in your child. They include:

• Maintaining good oral hygiene – Your child’s doctor may prescribe medication before specific oral or dental procedures to lower their risk of developing heart infections such as endocarditis.
• Limiting certain exercises and activities – Your child’s doctor may ask them to avoid or limit a few types of physical activity^[6], especially ones that are strenuous or tedious that can put pressure on your child’s heart. While this can differ from individual to individual, it is best to consult your child’s doctor to understand what activities are safe for your child to perform.

How Can Tetralogy of Fallot Affect Me as an Adult?

Adults with congenital heart defects would also have lifestyle restrictions and may need counselling around:

• Employment – based on your condition, a team of specialists may help you choose the right jobs/roles that help protect your heart and lower your risk of any complications. 
• Pregnancy – having heart rhythm problems or a heart defect can increase your risk of complications during pregnancy and hence, the decision to conceive should be thoroughly discussed with your doctor if you have congenital heart disease.

Support and Coping Strategies to Ease the Anxieties Around the Condition

• Seek Support from Friends and Family Members

Friends and family members can provide emotional support to the expectant mother. They can help encourage and ease stressors around pregnancy while also providing the physical help the mother requires during pregnancy and even after birth. 

• Attend Counselling Sessions with a Qualified Mental Health Therapist

If you’re struggling with your mental health during pregnancy or after birth, attending counselling sessions with a qualified mental health therapist can also help relieve the stresses and anxieties surrounding this stage of life. Mental health therapists are trained to listen without judgment and can offer practical solutions to help: Make your pregnancy a safe and enjoyable experience mentally and physically, ease worries and fears around your child’s overall health.

• Join a Support Group

Sometimes, knowing that you are not alone in your struggle can go a long way in building courage and confidence within yourself. Joining a support group of new mothers can help give you a platform to voice your concerns and also receive encouragement around your child’s health. 

• Increase Awareness of the Condition

It is a very rare condition, so it can be difficult for parents to know what Tetralogy of Fallot symptoms they should be concerned about. Therefore, increasing your knowledge and understanding about congenital heart defects can help you be well prepared mentally and physically for what may come. 

• Recording/Journalling Child’s Health

While tracking the progress of your child’s health is crucial from a medical standpoint, it can also somewhat serve as a motivator, especially when you see how far your child has come. Seeing how your child is growing can also give you a positive feeling and ease your worries around battling the condition over time.

Key Takeaways

• Making sure that you incorporate a healthy lifestyle and eating nutritious food can lower your risk of babies developing tetralogy of fallot symptoms.
• Monitoring your child’s health and keeping track of any symptoms that could potentially occur is a good way of staying vigilant.
• Some ways you can cope with the anxieties surrounding the tetralogy of fallot include seeking the support of family, friends or a mental health therapist, joining a support group, increasing your knowledge of the conditions and journaling your child’s health.

Also Read: Abdominal Aortic Aneurysm: Causes, Symptoms & Treatment

Frequently Asked Questions (FAQs)

References

1. Horenstein MS, Diaz-Frias J, Guillaume M. Tetralogy of Fallot. StatPearls. 2024 [cited 2025 Mar 10]. Available from: https://www.ncbi.nlm.nih.gov/books/NBK513288/
2. Bedair R, Iriart X. Educational Series in Congenital Heart Disease: Tetralogy of Fallot: diagnosis to long-term follow-up. Echo Research and Practice. 2018 Dec 17 [cited 2025 Mar 10]. Available from: https://pubmed.ncbi.nlm.nih.gov/30557849/ 
3. Yoo S ‐j., Lee Y ‐h., Kim ES, Ryu HM, Kim MY, Yang JH, et al. Tetralogy of Fallot in the fetus: findings at targeted sonography. Ultrasound in Obstetrics and Gynecology [Internet]. 1999 Jul 1;14(1):29–37. Available from: https://pubmed.ncbi.nlm.nih.gov/10461335/ 
4. Wang T, Li Q, Chen L, Ni B, Sheng X, Huang P, et al. Effect of maternal alcohol consumption during the pre-pregnancy/early-pregnancy period on congenital heart disease: A prospective cohort study in Central China. Preventive Medicine. 2022 Jan 20 [cited 2025 Mar 10]. Available from: https://pubmed.ncbi.nlm.nih.gov/35065976/ 
5. About Tetralogy of Fallot. Congenital Heart Defects (CHDs). 2024 [cited 2025 Mar 10]. Available from: https://www.cdc.gov/heart-defects/about/tetralogy-of-fallot.html
6. Tetralogy of Fallot. www.heart.org. 2024 [cited 2025 Mar 10]. Available from: https://www.heart.org/en/health-topics/congenital-heart-defects/about-congenital-heart-defects/tetralogy-of-fallot 
7. Tetralogy of Fallot: MedlinePlus Medical Encyclopedia. MedlinePlus. [cited 2025 Mar 10]. Available from: https://medlineplus.gov/ency/article/001567.htm 
8. Meijer JM. Pregnancy, fertility, and recurrence risk in corrected tetralogy of Fallot. Heart. 2005 May 13 [cited 2025 Mar 10]. Available from: https://pmc.ncbi.nlm.nih.gov/articles/PMC1768963/

Disclaimer: The information provided here is for educational/awareness purposes only and is not intended to be a substitute for medical treatment by a healthcare professional and should not be relied upon to diagnose or treat any medical condition. The reader should consult a registered medical practitioner to determine the appropriateness of the information and before consuming any medication. PharmEasy does not provide any guarantee or warranty (express or implied) regarding the accuracy, adequacy, completeness, legality, reliability or usefulness of the information; and disclaims any liability arising thereof.