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Last updated:
9/12/2023
Years published: 1986, 1994, 1996, 2005, 2007, 2023
NORD gratefully acknowledges Jamie Paik and Andrew Striegel, NORD Editorial Interns from the University of Notre Dame and Jason Buckley, MD, Department of Pediatrics, Division of Cardiology, Medical University of South Carolina, for assistance in the preparation of this report.
Truncus arteriosus is a rare type of heart disease that is present at birth. Affected individuals have one main blood vessel, rather than two, carrying blood away from the heart. Instead of having a separate pulmonary artery to carry blood to the lungs, and an aorta to carry blood to the rest of the body, a baby with truncus arteriosus has just one blood vessel leaving the heart which then branches into other blood vessels. Blood from both pumping chambers (ventricles) of the heart is mixed, resulting in a situation in which some oxygen-rich blood travels needlessly back to the lungs and some oxygen-poor blood travels to the rest of the body. The most common symptoms include a bluish tint to the skin (cyanosis) and rapid breathing (tachypnea). Standard treatment involves corrective open-heart surgery in the newborn period.
There are four types of truncus arteriosus:
Type I occurs when the left and right pulmonary arteries branch from the pulmonary arterial trunk.
Type II occurs when the left and right pulmonary arteries branch from the posterior of the common trunk.
Type III occurs when the left and right pulmonary arteries branch separately from the lateral walls of the common trunk.
Type IV occurs when a pulmonary artery trunk and pulmonary arteries do not form from the common trunk.
At birth, infants may have symptoms including a bluish tint to the skin (cyanosis), rapid breathing (tachypnea) and poor feeding (sweating with feeds, needing to stop and take breaks and difficulty gaining weight). Most infants have a heart murmur – a sound heard when the heart is listened to with a stethoscope. Some infants may develop an accumulation of fluid in the face, arms and/or legs.
Until surgical repair, truncus arteriosus leads to excessive blood flow to the lungs. This can result in congestive heart failure (the lungs are “congested” with fluid resulting in rapid breathing, poor feeding and difficulty gaining weight). Excessive blood flow to the lungs may also lead to abnormal enlargement of the heart (cardiomegaly) and over time, can result in high blood pressure in the lungs (pulmonary hypertension). When the blood pressure in the lungs is high, the amount of work that the heart must perform is increased and blood vessels in the lungs become vulnerable to permanent damage. The presence of high blood pressure in the lungs increases the risk of surgery, so truncus arteriosus is typically repaired within the first month of life.
Some infants with truncus arteriosus have an abnormal valve that connects the heart and the main blood vessel leaving the heart (the “truncal valve”). This valve can be too narrow (stenosis) or too leaky (regurgitation). Additionally, some infants with truncus arteriosus can have a narrowing or even complete interruption of the main blood vessel to the body (the aorta). These concurrent conditions can exacerbate the symptoms described above and/or increase the complexity and risk of surgery.
If surgery is not performed, the prognosis is very poor, and the life expectancy is shortened. Patients who do not undergo repair may experience recurrent respiratory infections, poor growth and development, high blood pressure in the lungs (pulmonary hypertension) and heart failure.
A single cause of truncus arteriosus has not been identified. Like many congenital heart defects, it has been suggested that the interaction of multiple genetic and environmental factors lead to this disease. The malformation of the heart that characterizes truncus arteriosus occurs during embryonic development. Medical literature suggests that variants of transmembrane protein 260 (TMEM260), a protein coding gene, may be associated with the development of type I truncus arteriosus.
Males and females are affected equally by this disease. This disorder occurs in approximately 1 in 15,000 births in the United States.
Approximately 35 percent of children with truncus arteriosus also have chromosome 22q11.2 deletion syndrome. Features of the syndrome vary but can include heart defects, immune dysfunction (difficulty fighting infections), low calcium level, developmental delay and facial differences. Physical characteristics may include wide-set eyes (hypertelorism), a downward slant to the eyes, notched and/or low-set ears and/or a small mouth. (For more information on this disorder, choose “chromosome 22q11.2 deletion syndrome” as your search term in the Rare Disease Database.)
While no direct cause of truncus arteriosus has been identified, some possible risk factors that have been associated with congenital heart disease include other family members who were born with heart defects and maternal health during pregnancy (e.g., diabetes, viral illnesses, alcohol use and use of certain medications).
Truncus arteriosus can often be detected before the baby is born by prenatal ultrasound evaluation that a mother receives as part of her prenatal care. If it is not detected prenatally, the signs and symptoms described above (rapid breathing, cyanosis, heart murmur etc.) often lead to an evaluation of the baby after birth by a pediatric cardiologist and an echocardiogram (ultrasound of the heart) is performed which confirms the diagnosis. A recording of the heart’s electrical activity (electrocardiogram), a CT scan and/or cardiac catheterization may also be used to further evaluate the heart. Cardiac catheterization is a procedure that measures pressures and oxygen levels within the heart and surrounding blood vessels. Angiography is often performed during cardiac catheterization and involves injection of dye to visualize the flow of blood as it moves through the heart structures.
Open heart surgery is necessary for the infant to thrive and for long-term survival. This corrective surgery will separate the arteries, close the hole in the ventricular septum (VSD) and reattach the pulmonary artery to the ventricle wall via a valve-containing tube (conduit). Without surgery, about 85% of patients will not survive past one year of age. Patients will require regular follow-up evaluation with a cardiologist.
Partial heart transplantation for severe pediatric semilunar valve dysfunction is a new valve replacement option being researched for neonates, infants and young children with severe valve abnormalities. More information can be found here: https://classic.clinicaltrials.gov/ct2/show/NCT05372757
Information on current clinical trials is posted on the Internet at www.clinicaltrials.gov. All studies receiving U.S. government funding, and some supported by private industry, are posted on this government website.
For information about clinical trials being conducted at the National Institutes of Health (NIH) in Bethesda, MD, contact the NIH Patient Recruitment Office:
Tollfree: (800) 411-1222
TTY: (866) 411-1010
Email: prpl@cc.nih.gov
For information about clinical trials sponsored by private sources, contact: www.centerwatch.com
For information about clinical trials sponsored in Europe, contact:
https://www.clinicaltrialsregister.eu/
REVIEW ARTICLES
Puri K, Allen HD, Qureshi AM. Congenital Heart Disease. Pediatr Rev. 2017 Oct;38(10):471-486. doi: 10.1542/pir.2017-0032. PMID: 28972050.
Silberbach M, Hannon D. Presentation of congenital heart disease in the neonate and young infant. Pediatr Rev. 2007 Apr;28(4):123-31. doi: 10.1542/pir.28-4-123. PMID: 17400823.
JOURNAL ARTICLES
Pagnamenta A, Jackson A, Perveen R, et al. Biallelic TMEM260 variants cause truncus arteriosus, with or without renal defects. Clin. Genet. 2022;101:127-133.
Poaty H, Pelluard F, André G, et al. Truncus arteriosus communis: report of three cases and review of literature. Afr Health Sci. 2018;18:147-156.
Tutarel O, Bertram H, Wessel A. Congenital heart disease and abnormalities of the great vessels. Am J Cardiol. 2004;94:278.
Volpe P, Paladini D, Marasini M, et al. Common arterial trunk in the fetus: characteristics, associations, and outcome in a multicentre series of 23 cases. Heart. 2003;89:1437-41.
Ullmann MV, Gorenflo M, Sebening C, et al. Long-term results of repair of truncus arteriosus communis in neonates and infants. Thorac Cardiovasc Surg. 2003;51:175- 79.
INTERNET
McElhinney D. Wernovsky G. Truncus Arteriosus. Medscape. Last Updated: Dec 31, 2019. www.emedicine.com/ped/topic2316.htm Accessed Sept 11, 2023.
Truncus arteriosus. Orphanet. March 2005. https://www.orpha.net/consor/cgi-bin/OC_Exp.php?Lng=GB&Expert=3384#:~:text=Truncus%20arteriosus%20(TA)%20is%20a,valve%20(i.e.%20truncal%20valve). Accessed Sept 11, 2023.
NORD strives to open new assistance programs as funding allows. If we don’t have a program for you now, please continue to check back with us.
NORD and MedicAlert Foundation have teamed up on a new program to provide protection to rare disease patients in emergency situations.
Learn more https://rarediseases.org/patient-assistance-programs/medicalert-assistance-program/Ensuring that patients and caregivers are armed with the tools they need to live their best lives while managing their rare condition is a vital part of NORD’s mission.
Learn more https://rarediseases.org/patient-assistance-programs/rare-disease-educational-support/This first-of-its-kind assistance program is designed for caregivers of a child or adult diagnosed with a rare disorder.
Learn more https://rarediseases.org/patient-assistance-programs/caregiver-respite/