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. Coronary arteries (which supply blood to the heart muscle) come out of the aorta just above the valve at the entrance of the aorta.
In 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, some goes to the coronary arteries, and the rest goes to the body. Usually, too much blood is sent to the lungs.
If this condition is not treated, two problems occur:
A murmur is usually heard when listening to the heart with a stethoscope.
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. 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 patient grows. Untreated cases result in death, often during the first year of life.
Call your health care provider if your infant or child:
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:Saunders Elsevier; 2011:chap 65.