In this condition, the embryological structure known as the truncus arteriosus fails to properly divide into the pulmonary trunk and aorta.

Under this system, English is now the official language, and persistent truncus arteriosus should properly be termed common arterial trunk.

[4][5] Microablation of the cardiac neural crest in developing chick embryos and genetic anomalies affecting this population of cells in rodents results in persistent truncus arteriosus.

[9] Collett/Edwards Types I, II, and III are distinguished by the branching pattern of the pulmonary arteries:[10][11] Another well-known classification was defined by Stella and Richard Van Praagh in 1965.

[11][12] In this classification scheme, the preceding letter ("A" or "B") refers to the presence or absence, respectively, of a ventricular septal defect.

The classification in the International Paediatric and Congenital Cardiac Code (IPCCC) attempts to eliminate this source of confusion with the following nomenclature scheme, which removes the use of numbered types:[2] Treatment is with neonatal surgical repair, with the objective of restoring a normal pattern of blood flow.