During fetal life, the eustachian valve directs oxygen-rich blood from the inferior vena cava (IVC) toward the foramen ovale and away from the tricuspid valve. After the closure of the foramen ovale, it does not have a specific function. In echocardiographic examinations, the eustachian valve may appear as a thin flap originating from the orifice of the IVC, or it may be totally absent. Sometimes it may appear as a rigid, elongated structure in the inferior portion of the right atrium or as a membranous, undulating, echogenic mass within the right atrial cavity.