Truncus arteriosus (TRUNG-kus ahr-teer-e-O-sus) is a rare heart condition present at birth. That means it's a congenital heart defect. In this condition, one large blood vessel leads out of the heart, instead of two.
Having only one large blood vessel means that oxygen-poor and oxygen-rich blood mix. This mixing reduces the amount of oxygen delivered to the body. It usually increases the amount of blood flow into the lungs too. The heart has to work harder to adjust for the changes in blood flow.
A baby, also called a fetus, with truncus arteriosus also usually has a hole between the two lower heart chambers, called the ventricles. The hole is called a ventricular septal defect.
Another name for truncus arteriosus is common arterial trunk.
Symptoms of truncus arteriosus most often occur in the first few days of life. They include:
If you are worried about your baby's feedings, sleep patterns or growth, contact a healthcare professional for an appointment.
Always seek emergency medical care if a baby has any of the following:
Truncus arteriosus occurs as a baby's heart forms during pregnancy. There's often no clear cause. Genetics and environmental factors may play a role.
To understand more about truncus arteriosus, it may be helpful to know how the heart typically works.
The typical heart has four chambers. They are:
The way the unborn baby's heart forms during pregnancy is complex. At some point, there is a single large blood vessel leading out of the heart. The vessel is called the truncus arteriosus. It usually splits in two as the unborn baby grows in the womb. One part becomes the lower end of the body's main artery, called the aorta. The other part becomes the lower part of the pulmonary artery.
But in some babies, the truncus arteriosus never splits. The wall separating the two lower heart chambers hasn't closed all the way. This results in a large hole between those chambers, called a ventricular septal defect.
Babies with truncus arteriosus also often have a problem with the heart valve that controls blood flow from the lower heart chambers to the single vessel. This valve may not close all the way when the heart relaxes. Blood can move the wrong way, back into the heart. This is called truncal valve regurgitation.
The exact cause of truncus arteriosus is unknown. But some things might increase the risk of a heart problem at birth. Risk factors include:
Truncus arteriosus causes severe problems with how blood flows through the lungs, heart and rest of the body.
Complications of truncus arteriosus in babies include:
Infants who had their hearts successfully fixed with surgery may still have complications later in life. Possible complications are:
Common symptoms of these complications include:
In rare cases, some people born with truncus arteriosus can survive without heart surgery. They may live into adulthood. But those with the condition will almost certainly have heart failure and develop a complication called Eisenmenger syndrome. This syndrome is caused by permanent lung vessel damage. It results in a significant lack of blood flow to the lungs.
Because the cause is unclear, it may not be possible to prevent truncus arteriosus. Getting good prenatal care is important. If you or someone in your family had a heart condition present at birth, talk to your healthcare professional before getting pregnant. You might need to see a genetic counselor and a heart doctor, called a cardiologist.
If you decide to get pregnant, taking these steps can help keep your baby healthy:
Truncus arteriosus is usually diagnosed soon after a child is born. The baby may look blue or gray and have trouble breathing.
When a baby is born, a healthcare professional always listens to the baby's lungs to check breathing. If a baby has truncus arteriosus, the healthcare professional may hear fluid in the lungs during this exam. The healthcare professional also listens to the baby's heart to check for irregular heartbeats or a whooshing sound, called a murmur.
Tests to diagnose truncus arteriosus include:
Infants with truncus arteriosus need surgery to improve blood flow and oxygen levels. Many procedures or surgeries might be needed, especially as a child grows. Medicines might be given before surgery to help improve heart health.
Children and adults with surgically repaired truncus arteriosus need regular health checkups for life.
Some of the medicines that might be given before truncus arteriosus surgery include:
Most infants with truncus arteriosus have surgery within the first few weeks after birth. The specific type of surgery depends on the baby's condition. Usually, the baby's surgeon:
The tube used to create the new pulmonary artery doesn't grow with a child. Follow-up surgeries are needed to replace the tube as the child grows.
Future surgeries may be done with a flexible tube called a catheter. This avoids the need for open-heart surgery. The healthcare professional inserts the catheter into a blood vessel in the groin and guides it to the heart. A new valve can be delivered through the catheter to the proper area.
Sometimes a small balloon at the tip of the catheter is inflated at the site of a blockage, making a blocked artery wider. This procedure is called balloon angioplasty.
After surgery for truncus arteriosus, a person needs lifelong follow-up care with a heart doctor specializing in congenital disease. This type of healthcare professional is called a congenital cardiologist.
If you or your child had truncus arteriosus, your healthcare professional may recommend taking a few steps to protect the heart.
Pregnancy. If you've had truncus arteriosus repair surgery and want to become pregnant, talk to your healthcare professional first. Ask about the possible risks and complications. It's best to be checked by healthcare professionals with training in adult congenital heart disease and high-risk pregnancies. Together, you and your care team can discuss and plan for any special care needed during pregnancy.
Depending on the level of lung damage that occurred before truncus arteriosus surgery, pregnancy might or might not be recommended. Pregnancy is considered very high risk for those with Eisenmenger syndrome and is not recommended.
Caring for a baby with a serious heart problem, such as truncus arteriosus, can be challenging. Here are some strategies that might be helpful.
Keep track of your baby's health history. Include details about any diagnosis, medicines, surgeries and other procedures. Note the dates for surgeries and procedures. Include dosages for medicines. Write down any healthcare professionals' names and phone numbers.
If possible, get a copy of medical reports. This information helps you remember who provided care. It's also helpful to healthcare professionals who are unfamiliar with your child's health history.
If possible, ask your family members about their medical history. Heart problems at birth can be passed down through families. So it's helpful to know if anyone in your child's family has a history of early heart problems.
Also make a list of questions to ask your baby's healthcare professional. Preparing this list can help you and your healthcare team make the most of your time together. Here are some questions you might want to ask:
Don't hesitate to ask other questions.
Your child's healthcare professional typically asks the following questions: