Subvalvular (Right ventricular outflow tract) Valvular Supravalvular (pulmonary truncus) Peripheral (at the bifurcation) Peripheral in the pulmonary artery Isolated PS occurs with a frequency of 9% of all congenital cardiac abnormalities and, combined with other cardiac abnormalities, with a frequency of nearly 21%. All forms lead to an obstruction of blood flow from the right ventricle to the pulmonary arteries. …
