Aortic valve stenosis (AS) causing obstruction to the left
ventricular outfl ow, and hence reduction of the cardiac output,
remains a therapeutic challenge for paediatric cardiologists
and cardiothoracic surgeons.
Infants that present at birth may have very dysplastic valves
with severe or critical AS and are typically the most diffi cult
to treat. This article therefore focuses on the management
of severe AS in the neonate. This article also revises the
embryology of the semi-lunar valves, as the morphology
of the aortic valve often dictates the treatment pathway.