While the eustachian valve persists in adult life, it essentially does not have a specific function after the gestational period.

There is a large variability in size, shape, thickness, and texture of the persistent eustachian valve, and in the extent to which it encroaches on neighboring structures such as the atrial septum.

In this case, it may demonstrate an undulating motion in real time echocardiography; and when it is quite large, it may be confused with right atrial tumors, thrombi, or vegetations.

[2] However, higher insertion of a giant eustachian valve, which mimics the echocardiographic appearance of divided right atrium, is very rare.

The eustachian valve, also called valvula venae cavae inferioris, was described for the first time by the Italian anatomist Bartolomeo Eustachi (born between 1500 and 1513, died 1574).