Advertisement

What is truncus arteriosus?

In normal heart anatomy, two blood vessels - the pulmonary artery (which connects to the lungs) and the aorta (which transports blood out to the rest of the body) - branch out from the heart. In truncus arteriosus, a single blood vessel (instead of two) emerges from the heart and then branches in two to create the pulmonary and aortic arteries. The single vessel is called the truncus arteriosus. It originates in the heart’s lower pumping chambers (the ventricles) and arises above a hole in the wall between the two ventricles (called a ventricular septal defect, or VSD). Sometimes the valve letting blood out of the heart (the truncal valve) will be malformed and create a narrowing or leakage of the valve.

The combination of the ventricular septal defect and the single artery where there should be two causes oxygen-poor blood to be circulated to the body. This is why babies with truncus arteriosus have a bluish discoloration (called cyanosis) to the skin, particularly the lips, fingernails and toenails.

Truncus arteriosus also forces the heart to work extra hard in an effort to supply oxygenated blood to the body and lungs. Over time, this stresses the blood vessels of the lungs and the pumping chambers of the heart, leading to heart failure.

Continue Learning about Congenital Heart Disease

How do doctors treat adults with congenital heart defects?
Gregory P. Fontana, MDGregory P. Fontana, MD
Learn about the methods and goals of surgery to treat adult patients with congenital heart disease. ...
More Answers
Do children with congenital heart disease need open-heart surgery?
Pooja Desai, MDPooja Desai, MD
Open-heart surgery is needed if a child is born with a heart defect that cannot be fixed using a cat...
More Answers
Dr. Emile Bacha - Why are some children born with congenital heart defects?
Dr. Emile Bacha - Why are some children born with congenital heart defects?
Dr. Emile Bacha - How are pediatric congenital heart defects treated?
Dr. Emile Bacha - How are pediatric congenital heart defects treated?

Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.