The aorticopulmonary septum is developmentally formed from neural crest, specifically the cardiac neural crest, and actively separates the aorta and pulmonary arteries and fuses with the interventricular septum within the heart during heart development.

Structure

In the developing heart, the truncus arteriosus and bulbus cordis are divided by the aortic septum. This makes its appearance in three portions.

Clinical significance

The actual mechanism of septation of the outflow tract is poorly understood, but is recognized as a dynamic process with contributions from contractile, hemodynamic, and extracellular matrix interactions. Misalignment of the septum can cause the congenital heart conditions tetralogy of Fallot, persistent truncus arteriosus, dextro-Transposition of the great arteries, tricuspid atresia, and anomalous pulmonary venous connection.