Congenital pulmonary stenosis (PS) is a congenital heart malformation (see this term) that is characterized by a right ventricular outflow obstruction with a clinical presentation that may vary from critical stenosis presenting in the neonatal period to asymptomatic mild stenosis. The obstruction in PS can be at the valvular, subpulmonary, or supravalvular levels (valvular, subpulmonary, supravalvular PS; see these terms).

In this case the right ventricle is more muscular than normal, causing a characteristic boot-shaped (coeur-en-sabot) appearance as seen on anterior- posterior chest x-rays. Right ventricular hypertrophy is commonly associated with any form of right ventricular outflow obstruction or pulmonary hypertension, which may in turn owe its origin to left-sided disease. The echocardiographic signs are thickening of the anterior right ventricular wall and the septum. Cavity size is usually normal, or slightly enlarged. In many cases there is associated volume overload present due to tricuspid regurgitation, in the absence of this, septal motion is normal.