With Interrupted Aortic Arch, the aorta is not fully developed and is separated into two, unconnected parts where a single arch would normally be formed. This malformation prevents normal blood flow through the aorta and obstructs blood flow to the lower body.
This defect is often accompanied by a VSD. Oxygenated blood flows across the VSD to the right ventricle, where it mixes with de-oxygenated and is pumped through the pulmonary artery to the lungs. Initially some of this mixed blood travels to the lower body through a PDA, shortly after birth this PDA begins to close, thus decreasing circulation to the lower body. Surgical intervention is required to remedy this defect.
View an animated heart with Interrupted Aortic Arch