Truncus arteriosus is a rare type of heart disease that occurs at birth (congenital heart disease), in which a single blood vessel (truncus arteriosus) comes out of the right and left ventricles, instead of the normal two vessels (pulmonary artery and aorta).
There are different types of truncus arteriosus.
In normal circulation, the pulmonary artery comes out of the right ventricle and the aorta comes out of the left ventricle, which are separate from each other.
With truncus arteriosus, a single artery comes out of the ventricles. There is usually also a large hole between the two ventricles (ventricular septal defect). As a result, the blue (without oxygen) and red (oxygen-rich) blood mix.
Some of this mixed blood goes to the lungs, and some goes to the rest goes of the body. Often, more blood than usual ends up going to the lungs.
If this condition is not treated, two problems occur:
Too much blood circulation in the lungs may cause extra fluid to build up in and around them, making it difficult to breathe.
If left untreated and more than normal blood flows to the lungs for a long time, the blood vessels to the lungs become permanently damaged. Over time, it becomes very hard for the heart to force blood to them. This is called pulmonary hypertension, which can be life-threatening.
Bluish skin (cyanosis)
Delayed growth or growth failure
Rapid breathing (tachypnea)
Shortness of breath (dyspnea)
Widening of the finger tips (clubbing)
Exams and Tests
A murmur is usually heard when listening to the heart with a stethoscope.
Heart catheterization (only needed in rare cases to help with the diagnosis or in planning a treatment strategy)
MRI of the heart
X-ray of the chest
Surgery is needed to treat this condition. The surgery creates two separate arteries.
Usually the truncal vessel is kept as the new aorta. A new pulmonary artery is created using tissue from another source or using a man-made tube. The branch pulmonary arteries are sewn to this new artery. The hole between the ventricles is closed.
Complete repair usually provides good results. Another procedure may be needed as the child grows, because the rebuilt pulmonary artery that uses tissue from another source will not grow with the child.
Untreated cases of truncus arteriosus result in death, often during the first year of life.
High blood pressure in the lungs (pulmonary hypertension)
When to Contact a Medical Professional
Call your health care provider if your infant or child:
Appears overly tired or mildly short of breath
Does not eat well
Does not seem to be growing or developing normally
If the skin, lips, or nail beds look blue or if the child seems to be very short of breath, take the child to the emergency room or have the child examined promptly.
There is no known prevention, but early treatment can often prevent serious complications.
Webb GD, Smallhorn JF, Therrien J, Redington AN. Congenital heart disease. In: Bonow RO, Mann DL, Zipes DP, Libby P, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 9th ed. Philadelphia, Pa: Elsevier Saunders; 2011:chap 65.
Kurt R. Schumacher, MD, Pediatric Cardiology, University of Michigan Congenital Heart Center, Ann Arbor, MI. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial team