Truncus Arteriosus is a rare type of congenital heart defect where a single blood vessel (the truncus arteriosus) comes out of the heart, instead of the normal two vessels (the aorta and the pulmonary artery). This single vessel then branches into the pulmonary artery, which carries blood to the lungs, and the aorta, which carries blood to the rest of the body. This condition leads to a mixture of oxygen-rich and oxygen-poor blood being sent both to the body and the lungs.

Characteristics of Truncus Arteriosus

  • Single Artery: The single large vessel coming out of the heart.

  • Ventricular Septal Defect (VSD): Nearly all infants with truncus arteriosus have a VSD, a hole between the heart's two lower chambers (ventricles).

  • Overriding Artery: The trunk overrides or straddles the VSD.

  • Abnormal Heart Valves: The valve of the truncus arteriosus is often abnormal and can be either stenotic (narrowed) or regurgitant (leaky).

Symptoms

Symptoms of truncus arteriosus typically appear in the first few days of life and can include:

  • Cyanosis (a bluish tint to the skin, lips, and fingernails)

  • Rapid or labored breathing

  • Poor feeding

  • Fatigue

  • Poor growth

Diagnosis

Diagnosis usually involves:

  • Echocardiogram: To view the structure and function of the heart.

  • Chest X-ray: To see the size and shape of the heart and lungs.

  • Electrocardiogram (ECG): To measure the heart's electrical activity.

  • Cardiac catheterization: In some cases, for detailed information about the heart's structure and function.

Treatment

Treatment for truncus arteriosus involves surgery, usually performed within the first few weeks of life. The surgical procedure typically includes:

  • Closing the VSD to direct blood from the left ventricle through the truncus arteriosus to the body.

  • Creating a connection between the right ventricle and the pulmonary arteries (using a conduit or graft) to direct blood to the lungs.

Long-term Outlook

The prognosis for infants with truncus arteriosus who undergo surgery has improved significantly with advances in surgical techniques and medical care. However, these children require lifelong monitoring by a cardiologist, as they may have complications such as problems with the heart valve, the need for additional surgeries (especially to replace the conduit as the child grows), heart rhythm abnormalities, and other heart-related issues. Regular follow-up is essential to monitor and manage these potential complications.