Truncus Arteriosus

It’s natural for you to be concerned right now about your child’s health—a diagnosis of truncus arteriosus can be overwhelming. But you can rest assured that at Children’s Hospital Boston, your child is in expert hands.

Our cardiologists, cardiac surgeons, cardiovascular imaging professionals and other clinicians have extensive experience with even the most complex heart problems. Each year, we treat thousands of children, adolescents and even adults with a wide variety of heart defects and disorders.

Comparison with normal heart

In a normal heart, oxygen-poor (blue) blood returns from the body to the right atrium, and is pumped by the right ventricle through the pulmonary artery into the lungs. In the lungs the blood receives oxygen (and gives up carbon dioxide), then returns to the left atrium on the left side of the heart. The left ventricle pumps the oxygen-rich blood through the aorta out to the body.

Visit Heart and Blood Vessels for more on how the normal heart works.

But in truncus arteriosus, oxygen-poor (blue) and oxygen-rich (red) blood mixes in the common truncal vessel. Some of the mixed blood flows through the branch that becomes the pulmonary artery and on to the lungs, and some of it goes into the aortic branch and continue to the body.

The mixed blood that goes to the body doesn’t have as much oxygen as the body needs, and causes varying degrees of cyanosis (blue color of the skin, lips and nailbeds).

Open heart surgery to separate the pulmonary artery and the aorta is needed, and is usually performed in the first few weeks of the baby’s life.

Are there additional heart defects associated with truncus arteriosus?

• Babies with truncus arteriosus also have a ventricular septal defect (VSD), an opening in the wall of tissue (ventricular septum) that normally separates the right and left ventricles. The VSD is closed at the time of surgical correction of the truncus arteriosus.
   
• Often, the valve of the single vessel is defective in form and function, with abnormal leaflets that allow leakage (regurgitation) and/or obstruction of blood flow.

• Truncus arteriosus can be associated with chromosomal disorders such as velo-cardio-facial syndrome (also known as 22q11 deletion syndrome or DiGeorge syndrome).
   

Are there different variations of truncus arteriosus?

Yes, there are several different variations of the defect, depending on where and how the arteries arise from the trunk, and how the aortic arch is formed. Our doctors are highly experienced in treating all forms. The diagram below shows two different systems (Collett & Edwards and Van Praagh) for classifying the defect’s variations.

           What are the signs and symptoms of truncus arteriosus?

The most common symptoms include:

• cyanosis (blue color of the skin, lips and nail beds)
• fatigue
• sweating
• pale skin
• cool skin
• rapid breathing
• heavy breathing
• rapid heart rate
• congested breathing
• disinterest in feeding, or tiring while feeding
• poor weight gain

How do you diagnose truncus arteriosus?

Your child's physician may have heard a heart murmur during a physical examination and referred your child to a pediatric cardiologist for a diagnosis. A heart murmur is simply a noise caused by the turbulence of blood flowing through the heart defects. Symptoms your child exhibits also help with the diagnosis.

Diagnostic tests are needed to help confirm the diagnosis, and may include:

• echocardiogram (echo, cardiac ultrasound)—the chief method of detection and evaluation of truncus arteriosus
• chest x-ray
• electrocardiogram (ECG or EKG)

In addition to the above, follow-up testing after surgery and as your child grows can include:

• cardiac catheterization (cardiac cath)
• cardiac magnetic resonance imaging (MRI)

For details, see Tests.

How does Children’s treat babies with truncus arteriosus?

Your baby most likely will be admitted to Children’s Cardiac Intensive Care Unit (CICU) once her symptoms become apparent.

Truncus arteriosus must be treated by surgical repair. Your child may need to be on medication until the operation can take place. Treatment may include:

Before surgery:

• medications and diuretics
• high-calorie feedings

Surgical repair:

• usually performed as soon as the infant is diagnosed—before the blood vessels in the lungs are overwhelmed by extra blood flow and become diseased
• pulmonary arteries detached from the common artery (truncus arteriosus)
• pulmonary arteries connected to the right ventricle
• VSD (ventricular septal defect) closed with a patch
• truncal valve pumps to the body

For details, see Treatment & Care.

How should we care for our child after surgery?

After surgery, your child’s cardiologist will offer recommendations for follow-up care, including:

• wound care while your baby is healing
• a nutritional program to encourage weight gain

As your baby recovers and grows, be sure to follow a regular program of well-baby/well-child checkups.

Will my child be OK after surgery?

Many infants who have surgery for truncus arteriosus will grow and develop normally, with activity levels, appetite and growth eventually returning to normal. But your child will need to be followed periodically by a pediatric cardiologist, who will check for any heart-related problems.

Future procedures may be necessary before adulthood if:

• the pulmonary artery branches are small and don’t grow well after surgery
• the homograft or conduit connecting the right ventricle to the pulmonary artery—as well as any patches used in the initial repair—deteriorate and need to be replaced
• the aortic (truncal) valve begins to leak (regurgitate)

What causes truncus arteriosus?

The heart forms during the first eight weeks of fetal development. The problem occurs at the midpoint of this time, when the aorta and the pulmonary artery don’t divide to form two distinct vessels, but rather, remain as a single great vessel. It isn’t entirely clear what causes congenital heart malformations, including truncus arteriosus, although in most cases it appears that some combination of genetics and environmental factors is involved.

Truncus arteriosus and some other cyanotic congenital heart defects are sometimes associated with chromosomal disorders. If your child has such a disorder, Children’s will arrange for a genetics consultation and referral to other specialists as needed.

Will my child be OK in the long term?

Your cardiologist will help you create a long-term care program as your baby grows into childhood, the teen years and even adulthood. Most of our patients who’ve had congenital heart disease have an ongoing relationship with their Children’s cardiologist. We’ll prevent and treat complications, and will advise on daily-life issues, such as exercise and activity levels, nutrition and precautions related to pregnancy.

Genetic syndromes are relatively common with truncus arteriosus. If your child has a syndrome, we will arrange for a genetics consultation and referral to other specialists as needed.

Surgical techniques for treating congenital heart defects are continually being refined, and Children’s surgical success rates are very high. Nevertheless, your child will need periodic monitoring, since she will be at some risk for:

• narrowing or deterioration of the surgical repairs (she will outgrow the homograft or conduit)
• leaky heart valves
• abnormal heart rhythms (arrhythmias)

Where can my child find care and support when she grows up?

• The Boston Adult Congenital Heart and Pulmonary Hypertension Service (BACH) provides long-term inpatient and outpatient care and advanced therapeutic options for patients with congenital heart disease and pulmonary hypertension as they reach and progress through adulthood.
  BACH is an international center for excellence, with physicians and services from Children’s, Brigham and Women’s Hospital and the Beth Israel Deaconess Medical Center. The center promotes and supports clinical and scientific research for the advancement of care of these patients, and is a leader in the education of providers caring for this unique population.
• The Adult Congenital Heart Association (ACHA) is a national not-for-profit organization dedicated to improving and extending the life of adults with congenital heart defects, now thought to number at least 1 million. The organization serves and supports many such adults, their families and the medical community, as well as conducting research and providing advocacy, outreach and education.

FAQ

Q: What is truncus arteriosus?
A: Everyone starts with a single vessel that divides into two; in truncus arteriosus this division or separation doesn't occur. The condition is a cyanotic congenital heart defect in which a single prenatal vessel fails to separate into the two “great” vessels that take blood away from the heart to the lungs (the pulmonary artery) or to the body (the aorta).

Q: Are there other defects associated with truncus arteriosus?
A: Yes—children with truncus arteriosus also have a ventricular septal defect(VSD), which is a hole in the wall (septum) separating the left and right pumping chambers (ventricles) of the heart, and which allows blood from both sides of the heart to mix in the one great artery or truncus.

Q: What causes truncus arteriosus?
A: The heart forms during the first eight weeks of fetal development. The problem occurs in the midpoint of that time, when the single great artery or truncus fails to divide to form two separate vessels (the pulmonary artery and aorta). It isn’t clear what causes congenital heart malformations, including truncus arteriosus, although in most cases it appears that some combination of genetics and environmental factors is involved.

Truncus arteriosus and some other cyanotic congenital heart defects are sometimes associated with 22q11 deletion syndrome and other syndromes.

Q: If my child has truncus arteriosus, will she be OK?
A: Most infants who have truncus arteriosus surgery grow and develop normally. But your child will need to be followed periodically by a pediatric cardiologist, who will monitor her for any heart-related problems. Additional procedures may be necessary as your child grows.

Q: What are the symptoms of truncus arteriosus?
A: The most common symptoms include:

• cyanosis (blue color of the skin, lips and nail beds)
• fatigue
• sweating
• pale skin
• cool skin
• rapid breathing
• heavy breathing
• rapid heart rate
• congested breathing
• disinterest in feeding, or tiring while feeding
• poor weight gain

Q: How does Children’s treat truncus arteriosus?
 

A:     

Before surgery:

• medications and diuretics
• high-calorie feedings

Surgical repair:

• usually performed as soon as the infant is diagnosed—before the blood vessels in the lungs are overwhelmed by extra blood flow and become diseased
• pulmonary arteries detached from the common artery (truncus arteriosus)
• pulmonary arteries connected to the right ventricle
• VSD (ventricular septal defect) closed with a patch

Q: Can there be complications after surgery?
A: Infrequently, complications can occur, such as:

• infection
• respiratory problems (such as fluid in the lungs)

Q: What should we do at home after surgery?
A: After surgery, your child’s cardiologist will offer recommendations for follow-up care, including:

• wound care while the baby is healing
• a nutritional program to encourage weight gain

As your baby recovers and grows, be sure to follow a regular program of well-baby/well-child checkups.

Q: What’s the long-term outlook for my child?
A: Your cardiologist will help you create a long-term care program as your baby grows into childhood, the teen years and even adulthood. Most of our patients who’ve had congenital heart disease have an ongoing relationship with their Children’s cardiologist. After truncus arteriosus, your growing child will need periodic monitoring, since she will be at some risk for:

• abnormal heart rhythms (arrhythmias)
• leaky heart valves
• narrowing or deterioration of the surgical repairs (she will outgrow the homograft or conduit)

Q: What is Children’s experience treating congenital heart defects?
A: Children’s surgeons treat some of the most complex pediatric heart conditions in the world, with overall success rates approaching 98 percent—among the highest in the nation for large pediatric cardiac centers.

Our experts have pioneered some of medical science’s most advanced heart treatments, now in use around the globe. Children’s is among the only major pediatric heart centers in the world performing fetal heart interventions for certain congenital defects.

Causes

As a congenital heart defect, truncus arteriosus is a structural heart problem that your child was born with.

The heart forms during the first eight weeks of fetal development. The problem occurs in the midpoint of that time, when the aorta and the pulmonary artery don’t divide to form two separate vessels, but rather, remain as a single great vessel. It isn’t clear what causes congenital heart malformations, including truncus arteriosus, although in most cases it appears that some combination of genetics and environmental factors is involved.

Truncus arteriosus and some other cyanotic congenital heart defects are sometimes associated with some chromosomal disorders.

What are the signs and symptoms of truncus arteriosus?

• cyanosis (blue color of the skin, lips and nail beds)
• fatigue
• sweating
• pale skin
• cool skin
• rapid breathing
• heavy breathing
• rapid heart rate
• congested breathing
• disinterest in feeding, or tiring while feeding
• poor weight gain

When to seek medical advice

Call your health care provider immediately if your baby is having difficulty breathing, is breathing rapidly, has a bluish color or seems to tire much too easily.

Questions to ask your doctor

If your child is diagnosed with truncus arteriosus, you may feel overwhelmed with information. It can be easy to lose track of the questions that occur to you. Lots of parents find it helpful to jot down questions as they arise—that way, when you talk to your child’s doctors, you can be sure that all your concerns are addressed.

Some questions might include:

• What’s happened to my child’s heart, and why?
• Are there different forms of truncus arteriosus? What form does my child have?
• What tests will you perform to determine a treatment for my child?
• Is this condition associated with a genetic syndrome? How will you determine whether or not it is?
• What are my child’s treatment options?
• Will my child be OK if she has truncus arteriosus? How soon will she be better?
• Will there be restrictions on my child’s activities?
• Will she need additional procedures as she grows?
• Will there be long-term effects?
• How should I talk to my child about her condition when she’s old enough to understand?
• What can we do at home?

Who’s at risk

Congenital heart defects usually occur sporadically (by chance), with no clear reason for their development. So, unless the condition is part of an underlying chromosomal disorder or syndrome, it’s difficult to predict who’s at risk.

For teens

If you’re a teen with a congenital heart defect, you have a lot to cope with. Besides the typical issues any teenager faces—from social acceptance to body changes and more—you’ll also have to deal with medical appointments and procedures, some delay of your natural wish for independence, feeling different and assuming a lot of personal responsibility for maintaining your own good health.

If you feel overwhelmed, depressed or anxious through this important time in your transition to adulthood, speak to your doctor, counselor, parent or teacher—they’re all on your team, and they all want to help.

For adults

If you were treated for congenital heart disease as a child, you’re probably being followed by your cardiologist, since complications from early heart disease can arise in adulthood.

You may need lifelong monitoring and medication, since you’ll continue to be at some risk for heart problems in the future. Going forward, your cardiologist will advise you on activity levels, pregnancy issues and certain lifestyle choices.

Fortunately, Children’s can help adults with congenital heart defects. Many adults who were patients at Children’s as babies or children continue to be monitored by the clinicians who have followed them since childhood.

In addition, our Boston Adult Congenital Heart and Pulmonary Hypertension Service (BACH) provides long-term inpatient and outpatient care and advanced therapeutic options for patients with congenital heart disease and pulmonary hypertension as they reach and progress through adulthood.

BACH is an international center for excellence, with physicians and services from Children’s, Brigham and Women’s Hospital and the Beth Israel Deaconess Medical Center. The center promotes and supports clinical and scientific research for the advancement of care of these patients, and is a leader in the education of providers caring for this unique population.

What you can do at home

After surgery, your child’s cardiologist will offer recommendations for follow-up care,

including:

• wound care while your baby is healing from surgery
• a nutritional program to encourage weight gain

As your baby recovers and grows, be sure to follow a regular program of well-baby/well-child checkups.

Truncus arteriosus glossary

• aorta: one of the heart’s two great arteries. In a normal heart, the aorta arises from the left ventricle and carries oxygen-rich blood out to the body. In truncus arteriosus, it remains connected with the pulmonary artery.
• cardiac catheterization(cardiac cath):provides detailed visual information and measurements about the structures and pressures inside the heart. Blood pressure and oxygen measurements are taken in the four chambers of the heart, as well as the pulmonary artery and aorta.
• cardiac/cardio-: pertaining to the heart
• cardiac magnetic resonance imaging (MRI): provides a picture of the heart and blood vessels, but without using x-rays. MRI is rarely used to diagnose babies with truncus arteriosus, but may be helpful in follow-up to surgery to detect complications.
• cardiac surgery: surgical procedure performed on the heart or one of the blood vessels connected to the heart
• cardiac surgeon: doctor who performs surgery on the heart. A pediatric cardiac surgeon performs surgery on the hearts of infants and children.
• cardiologist: doctor who diagnoses and treats heart problems non-surgically. A pediatric cardiologist treats infants, children and some adults with heart problems.
• chest x-ray:shows the size and spatial relationships of the heart within the child’s chest. It takes a few moments. There’s no pain or discomfort.
• cyanosis (cyanotic): blue color of skin, lips and nailbeds caused by a reduction in the amount of oxygen-rich (red) blood circulating in baby’s bloodstream
• congenital heart defect: heart defect present at birth. The heart usually starts to form in the first eight weeks of fetal development. It’s thought that most congenital heart defects develop during this period.
• diagnosis: medical determination of illness or disease based on history, physical examinations and advanced technology diagnostic testing tools
• echocardiogram(echo, cardiac ultrasound): evaluates the structure and function of your child’s heart using electronically recorded sound waves that produce a moving picture of the heart, heart valves and blood vessels. For more, see Tests.
• electrocardiogram(ECG or EKG):evaluates the electrical activity of your child’s heart. An EKG is usually the initial test for evaluating the causes of symptoms and detecting heart abnormalities, including truncus arteriosus. For more, see Tests
• heart-lung machine (cardio-pulmonary bypass): machine that does the work of the baby’s heart and lungs while open heart surgery is performed. The heart-lung machine protects the heart muscle, brain and other organs during the operation. 
• IV: intravenous, into the vein; one method of delivering medication
• neonatologist: doctor who specializes in illnesses affecting newborns, both premature and full-term
• pulmonary artery: one of the heart’s two great arteries, which normally arises from the right ventricle and carries oxygen-poor blood to the lungs, where it receives oxygen. In truncus arteriosus, it remains connected with the aorta.
• sporadic: occurring by chance, occasionally, not inherited
• signs and symptoms: the presenting reasons why a child needs medical attention. Characteristics such as onset, quality, triggers and severity help diagnosticians to determine a disease, or to decide which testing is needed to determine the disease.
• truncus arteriosus:a complex defect in which a single vessel (normally there are two separate arteries) arising from the heart functions as both the aorta and the pulmonary artery—the single great vessel has failed to separate completely, instead leaving a connection between the aorta and pulmonary artery.
• ventricular septal defect (VSD): a congenital (present at birth) heart defect in which there is a hole in the tissue wall (septum) that divides the two lower chambers of the heart (right and left ventricles). This occurs in all babies with truncus arteriosus. The VSD is surgically closed at the time of surgical repair of truncus arteriosus.