<P> The most common form of valvular anomaly is a congenital heart defect (CHD), called a bicuspid aortic valve . This results from the fusing of two of the cusps during embryonic development forming a bicuspid valve instead of a tricuspid valve . This condition is often undiagnosed until calcific aortic stenosis has developed, and this usually happens around ten years earlier than would otherwise develop . </P> <P> Less common CHD's are tricuspid and pulmonary atresia, and Ebstein's anomaly . Tricuspid atresia is the complete absence of the tricuspid valve which can lead to an underdeveloped or absent right ventricle . Pulmonary atresia is the complete closure of the pulmonary valve . Ebstein's anomaly is the displacement of the septal leaflet of the tricuspid valve causing a larger atrium and a smaller ventricle than normal . </P> <Table> <Tr> <Td> </Td> <Td> This section needs expansion . You can help by adding to it . (October 2014) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This section needs expansion . You can help by adding to it . (October 2014) </Td> </Tr>

Where do you find semilunar valves and how do they differ from a/v valves