Persistent truncus arteriosus

Persistent truncus arteriosus (PTA), also known as common arterial trunk, is a rare congenital heart disease where the embryonic truncus arteriosus fails to divide into the pulmonary trunk and aorta. This results in a single artery supplying mixed blood to systemic and pulmonary circulations.

Causes of PTA are often spontaneous but can be linked to genetic disorders like DiGeorge syndrome (chromosome 22q11 deletions) or teratogens affecting the cardiac neural crest cells, which contribute to the aorticopulmonary septum. Various factors such as growth factors, transcription factors, and gap junction proteins have been implicated in its development.

Pathophysiological features include a single artery from both ventricles, an abnormal truncal valve, large ventricular septal defect (VSD), pulmonary hypertension, and right-to-left shunting of blood.

Diagnosis is based on symptoms like cyanosis, heart failure signs, murmurs, and imaging findings. Hypocalcemia may indicate DiGeorge syndrome.

Classification systems include the Collett & Edwards (roman numerals) and Van Praagh (arabic with A/B prefixes) schemes, simplified in IPCCC as types based on aortic or pulmonary dominance.

Treatment involves neonatal surgery: closing VSD, detaching pulmonary arteries, using conduits. Follow-up may be needed for conduit replacements and valve issues.

PTA has a prevalence of less than 1%.