Malalignment of the outlet septum with rudimentary formation
of the leaflets of the pulmonary valve, so-called
absent pulmonary valve syndrome, is seen in around onetwentieth
of those alleged to have tetralogy of Fallot [13].
The presence of rudimentary valvar leaflets arrayed in circular
fashion at the ventriculo-pulmonary junction results
in free pulmonary regurgitation throughout foetal life.
The end result is that the chronic volume load of the right
ventricle is transmitted to the pulmonary arteries, with