The tricuspid valve is located between the right atrium and right ventricle of the heart. Consisting of three irregularly shaped flaps, the purpose is to control the backflow of blood from the right ventricle into the right atrium during contraction of the right ventricle. When the right ventricle contracts there is some blood, which will flow back into the atrium. It is this flow which pushes against the valvular flaps causing the valve to close.
During normal fetal development the tricuspid valve flaps are adhered to the septa (wall separating atrium from ventricle). As the fetal development progresses under normal circumstances the adhesive bonds holding the valve open will degenerate, allowing the valve flaps to move into their proper position.
One of the primary causes of tricuspid valve dysplasia, is the failure of the adhesive bonds to degenerate. This lack of degeneration can be partial or total in nature, and results in a range of right-side heart murmurs. Dependent upon the severity of the valvular deformation the work of the right-side of the heart is increased. If the malformation is severe enough it can lead to enlargement of the right atrium and ventricle. Eventually congestive heart failure can result.
Symptoms of tricuspid valve dysplasia are dependent upon the extent of the malformation, but some of the most common symptoms are: fluid retention, cool extremities and exercise intolerance (possibly followed by collapse).