Truncus Arteriosus in Indian Infants

Introduction

The heart, one of the most important organs in our body, is responsible for pumping blood around your body, delivering oxygen and nutrients to the cells. It is divided into four chambers. The upper chambers, which are the left and right atrias, receive blood, while the lower chambers, which are the left and right ventricles, pump blood out to the rest of the body. This is generally how a healthy heart functions. 

People with truncus arteriosus (TA) have one blood vessel coming out of the left and right ventricle instead of two. It is a rare birth defect of the heart. There are different types of truncus arteriosus, and they all have common abnormalities relating to the arteries (aorta and pulmonary artery) and ventricular septal defect, which is a hole between the lower two chambers of the heart. Infants with birth defects related to the heart should be given urgent medical attention at an institute that specialises in treating such ailments of the heart. Growing up, these children are required to stick to their doctor’s instructions and follow up regularly for routine heart health checkups.

What is Truncus Arteriosus

Truncus arteriosus^[1] is a heart defect found at birth (congenital). Usually, people have two blood vessels that emerge from the heart, one from the left ventricle and one from the right ventricle. For people with truncus arteriosus, only one blood vessel comes out of the heart. Because of this, oxygen-poor blood that is supposed to go to the lungs and oxygen-rich blood that is supposed to flow to the rest of the body get mixed with each other, and this causes a lot of circulatory problems for the baby.

The diagnosis of truncus arteriosus can be done during pregnancy or even after birth. Truncus arteriosus, if untreated, can be fatal. Therefore, it is necessary to seek immediate medical attention if it is suspected. Truncus arteriosus can be treated using surgery and medications. There are also lifestyle restrictions that may be placed on people with truncus arteriosus.

Normal heart development vs truncus arteriosus in newborns

Truncus arteriosus is one single vessel that is present in the heart of a developing fetus. Normally, the truncus arteriosus divides into two different blood vessels, namely the aorta and pulmonary artery. In some cases, during development, the condition fails to divide into two separate arteries, which leads to a mix-up of oxygenated and deoxygenated blood. In a baby with normal heart development, both an aortic valve (the valve located at the exit of the left ventricle of the heart where the aorta begins) and a pulmonary valve (the valve that is present between the right ventricle and the pulmonary artery) are present. However, in babies with this condition, only a common valve known as the truncal valve is present. Truncus repair is often required to fix the abnormalities of the truncal valve. The truncal valve can become too thick or too narrow, which blocks blood from leaving the heart. The truncal valve can also leak, making the blood leaving the heart flow back to it. To prevent blockage or leakage, truncus repair is required^[2].

How common is it in India and the world?

TA is a quite rare form of congenital heart disorder occurring in one out of every ten thousand births in India. All over the world, ten out of ten thousand infants may be affected by it. Gender does not play a role in this condition as male and female infants are affected in equal ratios^[3].

Truncus arteriosus in adults

More than 80% of infants with truncus arteriosus die within the first year if they don’t get the proper treatment. Therefore, the condition (another term for truncus arteriosus) is quite rare in adults. Adults with this condition have a very high risk of developing heart failure and pulmonary hypertension.

To Summarize

• Truncus arteriosus is a rare condition present at birth.
• The condition is associated with the lack of separation between the pulmonary artery and the aortic valve in the heart.
• The condition is most common in infants, while it is quite rare in adults.

Signs & Symptoms of Truncus Arteriosus

Detecting the signs and symptoms of truncus arteriosus at an early stage is crucial to getting the right treatment for this condition. Once you are aware of these symptoms, you can talk to your doctor so you can proceed on the right course. Some of these symptoms include.

• Bluish colour of the skin: This is one of the major symptoms. The bluish colouring of the skin indicates that the body is facing trouble getting a sufficient amount of oxygenated blood due to the mixing up of oxygenated and deoxygenated blood.
• Excessive sleepiness: Excessive sleepiness indicates that your baby lacks energy due to poor oxygen circulation in the body.
• Abdominal swelling: Another sign and symptom of the condition is abdominal swelling. Abdominal swelling might occur due to other health issues. Therefore, this issue is often neglected. 
• Pounding heart: One of the major symptoms of this condition is a pounding heart or palpitations. The heart in an infant with this condition has to work hard to pump blood to the entire body. Therefore, the heart beats faster than usual and creates a pounding feeling. 
• Rapid breathing: Infants with this condition often experience rapid breathing. This happens due to the lack of oxygen in the body. 
• Poor feeding: Infants with the condition can face difficulty in breastfeeding.
• Poor growth: The condition is also associated with poor growth and low body weight in infants. If you see constricted growth in your infant, do not hesitate to visit the doctor.

At what stage of life do symptoms occur?

The symptoms of this condition can be noticed in infants right after birth. Since the heart works too hard to pump blood, the symptoms are quite visible. The symptoms create a need for truncus arteriosus repair.

When to see a doctor?

A doctor consultation should be opted for immediately after noticing the symptoms in your infant. Some emergencies in infants with truncus arteriosus include the following:

• Loss of consciousness
• Worsening of cyanosis (bluish tint on the skin)
• Shallow, rapid or laboured breathing

To Summarize

• The signs and symptoms of this rare heart condition include cyanosis, rapid breathing and excessive sleepiness.
• The symptoms show up right after suggesting the requirement for truncus arteriosus repair.
• Some emergencies, including loss of consciousness, create the need for immediate medical consultation.

Causes and Risk Factors of Truncus Arteriosus

Truncus arteriosus occurs during the development of the baby in the womb. The exact cause of the condition is unknown, but factors that increase the risk include:

1. Alcohol

Women who drink alcohol during pregnancy are at higher risk of giving birth to babies with this condition. Especially during the first trimester of pregnancy, alcohol consumption can be quite risky^[4].

2. Obesity

Women with obesity are at an increased risk of giving birth to babies with this condition and other congenital diseases.

3. Smoking during pregnancy

If a woman continues smoking during pregnancy, it increases the risk of giving birth to a baby with heart defects.

4. Chromosomal disorders

Chromosomal disorders like velocardiofacial syndrome (a genetic disorder involving a cleft palate) or DiGeorge’s syndrome (a condition that results in the poor development of many body parts) increase the risk of the condition in infants.

5. Uncontrolled diabetes during pregnancy

This can increase the risk in newborns. High blood sugar levels can also cause other heart disorders in newborns.

6. Certain medications during pregnancy

During pregnancy, a woman should be careful about the medicines they are taking. No medicines should be taken during pregnancy without a doctor’s consultation. Some medications can cause a developmental abnormality in newborns like persistent truncus arteriosus.

7. Viral illnesses like Rubella during pregnancy

If the mother contracts viral diseases like Rubella during pregnancy, it puts the baby at risk of congenital heart diseases. Persistent truncus arteriosus is one of the heart disorders that can occur due to viral illnesses.

To Summarize

• Habits like smoking and drinking during pregnancy can put the baby at risk of congenital heart diseases.
• Some chromosomal disorders in babies can also be the cause of truncus arteriosus.
• Other causes of truncus arteriosus include certain medications during pregnancy and contraction of viral diseases during pregnancy.

Diagnosing and Treating Truncus Arteriosus in Newborns

Diagnosing and treating truncus arteriosis in newborns is key to helping them find the best method in controlling this condition. With this in mind, and depending on the health condition of the newborn, there are diagnostic tests that may be recommended by your doctor. A few of those tests are given below.

Diagnosis during pregnancy

• By prenatal screening tests like Fetal Echocardiogram

The process during pregnancy helps in checking the heart of a developing baby. It is beneficial in detecting heart defects in babies before they are born. The test allows the doctor to see the heart structure of an unborn baby and find out if it’s working effectively. The test is typically done between 18 to 24 weeks, which is the second trimester of pregnancy^[5].

Post-birth truncus arteriosus diagnosis

• External breathing assessment

The breathing rate of infants is examined to check if they are facing any breathing trouble. If their breathing is shallow, rapid or laboured, it might be indicating heart defects.

• Assessment for arrhythmias and murmurs

A doctor listens to a baby’s heart to determine if it beats irregularly (arrhythmia). Sometimes, an abnormal sound in the heart is also caused by the turbulent flow of blood. This abnormal sound is known as a heart murmur.

• Echocardiogram

An echocardiogram reveals the structure and function of the heart. Here, sound waves are used to produce images of the heart on a monitor. If an infant has the condition, the echocardiogram will show the presence of a single vessel from the lower chambers of the heart. Sometimes, there can also be a hole in the wall between the right and left ventricles of the heart. An echocardiogram also shows how much blood flows to the baby’s lungs. It will help in knowing if there’s a high risk of increased blood pressure in the lungs.

• Chest x-ray

A chest x-ray will help in producing still images of the heart and lungs with radiation. The size of the heart and any abnormalities in the heart and lungs can be revealed in a chest X-ray. The presence of excessive fluid in the lungs can also be determined with the help of a chest X-ray.

Preparing for the diagnosis 

A mother needs to be aware of both her own and the child’s father’s medical history. Some heart problems are genetic, so knowing the family medical history can help a great deal. You can prepare a list of questions that might be helpful to ask the doctor. It is also necessary to ask what kind of diagnostic tests your child needs. The doctor might ask you a few questions related to the symptoms of truncus arteriosus. The doctor might ask if your baby appears blue and for how many hours your baby sleeps. It is a good idea to write down the symptoms you notice in your baby.

Treating Truncus Arteriosus

Your doctor will advise on the best course to start the treatment. Following the detection of symptoms and the procedure, thorough follow-ups will be conducted. With that being said, there are quite a few approaches to treating truncus arteriosus, which are listed below.

1. Surgery

The surgery is usually done within the first few weeks of birth. The surgical procedure primarily depends on the health condition of the baby^[6]. Some common steps included in the surgery are as follows:

• Closing the hole between the right and left ventricle using a patch.
• Separating the upper part of the pulmonary artery from the truncal valve. 
• A valve and tube are implanted to connect the upper portion of the pulmonary artery with the right ventricle. It helps in creating a completely new pulmonary artery. 
• Reconstructing the aorta and the single large vessel to create a completely new aorta.

After having corrective surgery, a child needs to be under lifelong follow-up with a cardiologist. Some physical activities might be restricted after corrective surgery. Sometimes, a child needs multiple corrective surgeries.

A child with corrective surgeries will have to be on antibiotic dosage before dental surgeries or other surgical procedures. Antibiotics will help in preventing infections. As the artificial valve will not grow as your child grows, follow-up surgeries will need to be conducted. 

2. Cardiac catheterization

Treatment is also possible with minimally invasive procedures in some cases. These procedures using a cardiac catheter are good alternatives for traditional open-heart surgeries. The catheter (a thin tube) is implanted into a blood vessel and threaded up to the heart. Sometimes, cardiac catheterisation with a balloon tip is done to reopen a narrowed or blocked artery. 

3. Medications

Treatment in infants is done by a pediatric cardiologist. In adults, the treatment is done by a cardiothoracic cardiac surgeon. These specialists will prescribe certain medications based on the patient’s age, the severity of the symptoms and their underlying conditions. These medications can help manage the condition better and improve the outlook.   

4. Nutrition 

Babies with the condition become tired while being fed. When they don’t eat adequately, their growth is hindered. Most babies with the condition are underfed and underweight. Therefore, a high-calorie formula might be prescribed to promote weight gain in infants. Infants who become too tired while eating are required to be fed using a feeding tube. Food is given to them through these small and flexible tubes that pass through the nose, down the oesophagus and into the stomach.

Complications of Truncus Arteriosus If Left Untreated

If the condition is not treated properly using the appropriate medications or corrective surgeries, it can increase the risk of developing other health conditions. Here are a few of the complications that truncus arteriosus can lead to.

1. Progressive pulmonary hypertension

If the condition is left untreated, it leads to progressive pulmonary hypertension. It is characterised by high blood pressure in the lung arteries without any reason.

2. Irregular heart rhythm

The condition also leads to irregular heart rhythms in patients. The medical term for an irregular heartbeat is arrhythmia. Arrhythmia feels like the heart skipped or added a beat or is fluttering. The heart might beat too fast or too slow due to arrhythmia.

3. Problems related to the prior operation

Truncus arteriosus also causes issues related to other surgeries. It can increase the risk of infections from prior surgeries. Patients with truncus arteriosus need to be on antibiotics before undergoing any kind of surgery.

4. Leaky heart valves

Truncus arteriosus is also associated with leakage in the heart valves. Due to the leakage, the blood flowing out of the heart can flow back to the heart.

5. Death

Children with the condition have a high chance of mortality in the first year of life.

To Summarize

• Sometimes, multiple surgeries need to be conducted in patients with truncus arteriosus.
• Certain medications can help manage the condition effectively.
• Some long-term complications associated with this condition are pulmonary hypertension and arrhythmia.

Tips and Lifestyle Changes to Reduce the Risk of Truncus Arteriosus

The exact cause of truncus arteriosus is not well known; therefore, absolute prevention is not possible. Following a healthy diet and lifestyle during pregnancy may help prevent some defects in the developing baby. Here are some tips for women who plan to conceive-

• Controlling diabetes, BP and body weight: A woman with diabetes should consult the doctor before getting pregnant. Diabetes, BP and body weight need to be under control during pregnancy to avoid heart-related complications in the baby.
• Getting vaccinated before getting pregnant: Viral infections like German measles can be deadly during pregnancy. Therefore, it is important to check if you have the proper immunisations before getting pregnant. If you have not been vaccinated with necessary immunisations, take them before planning for pregnancy.
• Avoiding dangerous medications: Some medications can have harmful effects on pregnant women. You should always consult your doctor before taking any medication during pregnancy or when you are planning for pregnancy.
• Take a daily dose of folic acid: Taking a daily dose of folic acid can be quite helpful during pregnancy. It can prevent birth defects, including heart problems and spinal cord disorders. However, it is recommended to consult your doctor before taking this.
• Avoiding alcohol/smoking: Consumption of alcohol or smoking during pregnancy can be too dangerous for the baby. It can cause a wide range of problems in the baby, including heart issues.

To Summarize

• Keeping diabetes in control during pregnancy can help in avoiding the risk of the condition.
• Avoid medications that can be harmful to the baby. Smoking and drinking should be completely avoided during pregnancy to reduce the risk in patients.
• A regular dosage of folic acid during pregnancy can help in managing a lot of birth defects, including heart issues.

Support and Coping Mechanisms for Parents

1. Seeking comfort and strength

The support and coping mechanisms parents need to receive will help you form a better frame of mind when dealing with this condition. It is always important to find an outlet and find your sources for the most accurate information.

2. Seeking support from friends and family members

If you have an infant with truncus arteriosus, it can be quite difficult to take care of them on your own. Do not hesitate to ask for support from friends and relatives. You can ask someone you trust to accompany you to the doctor’s appointments.

3. Increasing awareness of the condition

The caregiver must have adequate information about the health condition. You need to learn about the symptoms and precautions that your child must follow throughout their life. You should know which symptoms require you to seek immediate medical attention. It is also important to know about the behaviours and activities that can aggravate the condition. Read relevant articles, watch videos, and ask your doctor to become more aware of the condition.

4. Recording/journaling your baby’s health

If your baby has this condition, you should make it a habit to note down their symptoms. The frequency and intensity of the symptoms might change from it. Recording or journaling will ensure that you don’t miss out on any points during the medical appointments. It will also be beneficial when your child moves from pediatric to adult health care.

5. Joining a parenting support group where you can talk about your concerns

Sometimes, dealing with an infant with this condition can become very overwhelming. Joining a support group for parents will help you realise that there are other parents like you going through the same problems. You can vent out your feelings and raise your concerns in those support groups. It will be quite helpful in relieving your mental stress. Remember that you need to think about your mental and physical well-being while taking care of a child with this health condition.

6. Preparing for your doctor visits – some of the questions you can ask your doctor and answers you can be prepared for

You can ask your doctor any questions you have. Seeking answers to questions will help you realise if you are taking enough care of your child. You should be ready to follow all the instructions given by your doctor. If necessary, you can note down the instructions and refer to them later. Also, prepare a list of questions that you would like to ask the doctor before every appointment. A sample of questions that you might want to ask are as follows:

• What food items should I avoid feeding my child?
• If I think about another pregnancy in future, what are the chances of this condition happening again?
• What are the possible complications of the treatment my child is undergoing?

To Summarize

• You should not hesitate to ask for help from friends and family if you are struggling in taking care of your infant with the condition.
• Increase your awareness about the health condition of truncus arteriosus.
• Keep track of the symptoms exhibited by your infant and notify your doctor about the symptoms.

Also Read: Tetralogy of Fallot in Children: Symptoms, Causes and Treatment

Frequently Asked Questions (FAQs)

References

1. Vanpraagh R. Truncus arteriosus: what is it really and how should it be classified? European Journal of Cardio-Thoracic Surgery. 1987 [cited 2025 Mar 4]. Available from: https://pubmed.ncbi.nlm.nih.gov/2856609/
2. The formation, septation and fate of the truncus arteriosus in man. PubMed. 1982 [cited 2025 Mar 4]. Available from: https://pubmed.ncbi.nlm.nih.gov/7076544/
3. Reller MD, Strickland MJ, Riehle-Colarusso T, Mahle WT, Correa A. Prevalence of congenital heart defects in Metropolitan Atlanta, 1998-2005. The Journal of Pediatrics. 2008 [cited 2025 Mar 4]. Available from: https://pubmed.ncbi.nlm.nih.gov/18657826/
4. Ghafari S, Malaki M. Truncus arteriosus: A major cause of proteinuria in children. Journal of Cardiovascular Disease Research. 2011 [cited 2025 Mar 4]. Available from: https://www.sciencedirect.com/science/article/abs/pii/S0975358311240087
5. Abel JS, Berg C, Geipel A, Gembruch U, Herberg U, Breuer J, et al. Prenatal diagnosis, associated findings and postnatal outcome of fetuses with truncus arteriosus communis (TAC). Archives of Gynecology and Obstetrics. 2021 [cited 2025 Mar 4]. Available from: https://pubmed.ncbi.nlm.nih.gov/34028563/
6. Sandrio S, Rüffer A, Purbojo A, Glöckler M, Dittrich S, Cesnjevar R. Common arterial trunk: current implementation of the primary and staged repair strategies. Interactive Cardiovascular and Thoracic Surgery. 2015 [cited 2025 Mar 4]. Available from: https://pubmed.ncbi.nlm.nih.gov/26362626/

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