Truncus Arteriosus: A Comprehensive Guide

Truncus arteriosus is a rare congenital (present at birth) heart defect. In a normal heart, there are two separate arteries emerging from the heart: the pulmonary artery which carries deoxygenated blood from the heart to the lungs, and the aorta which carries oxygenated blood from the heart to the rest of the body. In babies with Truncus arteriosus, instead of these two separate arteries, there’s a single common arterial trunk. This means that both oxygen-rich and oxygen-poor blood mix together, causing the heart to work harder and reducing the oxygen supply to the body.


The symptoms of Truncus arteriosus often manifest early in a baby’s life, typically within the first few weeks. They include:

  1. Blue or pale gray skin color (cyanosis): Due to low oxygen levels in the blood.
  2. Rapid breathing or shortness of breath: The heart works harder to supply the body with oxygen.
  3. Poor feeding: Babies might become fatigued while feeding or might not be able to feed at all.
  4. Failure to gain weight: Due to feeding difficulties and the increased energy expenditure of the heart.
  5. Excessive sleepiness or fatigue: The body is starved of oxygen, causing lethargy.


The exact cause of Truncus arteriosus is still unknown, but it’s believed to result from abnormal development of the fetal heart during the first 8 weeks of pregnancy. Some factors might increase the risk, such as:

  1. Genetic disorders: Conditions like DiGeorge syndrome (a chromosomal disorder) can increase the risk of Truncus arteriosus.
  2. Environmental factors: Some medications, drugs, or illnesses during pregnancy may increase the risk.

Risk Factors

Several factors can increase the risk of a baby being born with Truncus arteriosus:

  1. Family history: A family history of heart defects can increase the risk.
  2. Maternal illnesses: Conditions such as rubella or other viral illnesses during pregnancy might increase the risk.
  3. Maternal lifestyle: Smoking, alcohol, or drug use during pregnancy can contribute.
  4. Maternal age: Women who become pregnant after 40 might have a slightly higher risk.

How to Avoid It

While not all cases of Truncus arteriosus can be prevented, some measures might reduce the risk:

  1. Prenatal care: Regular check-ups can help in early detection and management.
  2. Healthy lifestyle: Avoiding smoking, alcohol, and illicit drugs during pregnancy.
  3. Medication review: Ensure that any medication taken during pregnancy is safe and review it with your doctor.
  4. Vaccinations: Ensure you’re up-to-date with vaccinations, especially against rubella.

When to See the Doctor

If your baby displays any of the aforementioned symptoms, especially difficulty in feeding, cyanosis, or rapid breathing, it’s crucial to seek medical attention immediately. Early diagnosis can improve the outcome and quality of life for children with this condition.


Types of Truncus Arteriosus

Truncus arteriosus is classified into four types based on the anatomical details:

  1. Type 1: A single vessel arises from the heart, giving rise to the coronary, pulmonary, and systemic arteries.
  2. Type 2: The pulmonary arteries arise from the posterior aspect of the common trunk.
  3. Type 3: The pulmonary arteries originate from the lateral aspects of the common trunk.
  4. Type 4 (Pseudotruncus): This is actually a form of pulmonary atresia with a ventricular septal defect and has a very different physiology from the other types.


The diagnosis of Truncus arteriosus is usually made through a combination of physical examinations, reviewing symptoms, and conducting imaging studies:

  1. Echocardiogram: This is the most common diagnostic method. It uses sound waves to produce detailed images of the heart, showing the common arterial trunk and the mixing of blood.
  2. Cardiac Catheterization: A thin tube (catheter) is inserted into a blood vessel and threaded to the heart, providing detailed information about the heart’s structure and function.
  3. Electrocardiogram (ECG): This test records the electrical activity of the heart and can help diagnose heart defects.
  4. Chest X-ray: It can show structural abnormalities in the heart and lungs.
  5. Genetic testing: As Truncus arteriosus is sometimes associated with genetic conditions like DiGeorge syndrome, genetic testing might be performed.


Treatment for Truncus arteriosus is surgical, and it’s usually performed within the first few weeks of life. The aim is to separate the pulmonary circulation from the systemic circulation.

  1. Repair Surgery: This is the main treatment. The surgeon closes the ventricular septal defect with a patch, separates the pulmonary arteries from the common trunk, and connects them to the right ventricle using a conduit or graft. The remaining part of the common trunk becomes the aorta.
  2. Follow-up surgeries: Over time, the conduit or graft might need to be replaced, especially as the child grows.


With early diagnosis and proper surgical intervention, many children with Truncus arteriosus can lead a full and active life. However, they’ll require lifelong follow-up care with a cardiologist to monitor their heart function and ensure they’re meeting developmental milestones.

Lifestyle Management

Children who have undergone surgery for Truncus arteriosus should receive regular follow-up care, take medications as prescribed, and engage in physical activities suitable to their condition. Parents should also be vigilant about signs of heart failure or complications.


Having a child with a congenital heart defect can be overwhelming for parents. Support groups, counseling, or talking with other parents who’ve gone through similar experiences can be helpful.

It’s important to remember that while Truncus arteriosus is a severe condition, advances in medical and surgical treatments have greatly improved the outcomes and quality of life for these patients.

In conclusion, Truncus arteriosus, while rare, is a serious congenital heart defect that demands early detection and intervention. A thorough understanding of the symptoms and risk factors can pave the way for better preventive measures and care for affected infants. As always, maintaining a healthy lifestyle during pregnancy and seeking regular prenatal care are pivotal steps toward ensuring the well-being of your baby.



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American Falls


Idaho Falls


Contact Information

(208) 233-2273

(208) 233-2490


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