Background
Pulmonic valvular stenosis (PVS) is described as lesions that collectively are associated with obstruction to the right ventricular outflow tract. Stenosis may be valvular, subvalvular, or supravalvular. Isolated pulmonary stenosis is considered to be a rare congenital abnormality.
It is the most common cause of congenital outflow tract obstruction, resulting in decreased flow from the right ventricle to the pulmonary arteries.
Isolated right ventricular outflow tract obstruction is pulmonic valvular stenosis in 80% of cases.
Pulmonic valvular disease is clinically detected at different stages of life. The more severe the obstruction, the earlier the valvular abnormality is typically detected. Pulmonic valvular stenosis is most often associated with the failure of the valvular leaflets to fuse and less commonly is caused by dysplastic thickening of the valves.
Neonates with critical stenosis typically present with central cyanosis at birth. Infants and children with ejection murmurs auscultated in the pulmonic area are often evaluated, and stenosis is discovered during this period. Symptoms of pulmonic stenosis have been observed to progress with time.
Adults present with symptoms of congestive heart failure (CHF) and right ventricular outflow obstruction that is progressive in nature.
Many of these congenital valvular malformations occur in the setting of well-defined syndromes. Examples of such syndromes involving stenosis of the pulmonic valves are Holt-Oram syndrome, Noonan syndrome, and Leopard syndrome.
Eisenmenger syndrome associated with trisomy 13 also results in pulmonary outflow tract obstruction; however, often, other cardiac malformations are involved as well.
A large study called the Second Natural History Study of Congenital Heart Defects analyzed the treatment, quality of life, echocardiography findings, complications, exercise responses, and predisposition to endocarditis with regards to cardiac valvular disease, and pulmonary stenosis was found to be the most benign valvular lesion.