Truncus arteriosus is a heart condition that occurs when blood with low levels of oxygen is pumped throughout the body, causing congestive heart failure.

In truncus arteriosus, the blood that is pumped out of the heart is a mixture of blood with oxygen and blood without oxygen. This means that the oxygen level of the blood is lower than what the body needs.

The heart pumps harder to get extra blood with oxygen out to the body, which causes babies to breathe faster and have trouble eating. Eventually the heart may not keep up with the extra work it needs to do. Some babies may need medications to support the heart as it does this extra work.

Truncus Arteriosus – Causes and Diagnosis

In most cases, there is no known specific cause for truncus arteriosus. DiGeorge syndrome is often associated with this condition. Parents may be tested to see if they carry the DiGeorge syndrome gene. A genetic counselor can better determine what the risk would be for future pregnancies. 

Truncus arteriosus is diagnosed in several ways, including:

  • Echocardiogram – an ultrasound of the heart
  • Fetal echocardiogram –  an ultrasound of the heart before birth
  • Failing the newborn pulse oximetry screen. The diagnosis would be confirmed with an echocardiogram.

Eventually, your baby will require surgery.

Care Providers

The University of Maryland Children's Heart Program team that treats truncus arteriosus includes a pediatric cardiac surgeon, pediatric cardiologists, pediatric and neonatal intensive care doctors and nurses, pediatric cardiac anesthesiologists, cardiac operating room staff, cardiac nurses and many others with expertise in providing this specialized cardiac care.  

If truncus arteriosus is diagnosed while you are pregnant, you will see a maternal fetal medicine specialist who will treat you during your pregnancy. 

Treating Truncus Arteriosus

Surgery for truncus arteriosus is usually done soon after birth, typically within the first week of life. The surgeon will close the ventricular septal defect (VSD) so that the left ventricle can pump blood to the truncus, which will be used as the aorta.

The surgeon removes the pulmonary artery branches from the truncus and connects them to the right ventricle using a tube made from a vein or prosthetic material. It provides an open pathway for blood to be pumped from the right ventricle to the lungs.

If the truncal valve (between the ventricle and the truncus) leaks a lot or does not open well, the surgeon will also try to repair the valve.

Most patients who have truncus arteriosus will need repeat surgeries later in life to replace the tube. The timing for replacement of a conduit is unpredictable but usually occurs 5-10 years from the initial surgery.

Contact Us 

  • To learn more about Maternal Fetal Heart medicine, please call 410-328-3865.
  • To make an appointment with a Children's Heart Program physician, please call 410-328-4348.