eustachian valve right atrium fetal heart

Prominent Eustachian valve and ridge as a normal variant

Case report:

In this fetus, at 35 weeks, we observed a thick and linear echogenic structure in the right atrium protruding laterally from the lower third of the interatrial septum and mimicking a Cor triatriatum dexter ⁽¹⁾. It was located in the inferior wall of the right atrium and was continuous with the superior border of the orifice of the coronary sinus.

Figure 1, 2: Arrows demonstrated the Prominent Eustachian valve.

Figure 4, 5: Anatomy of the heart: SVC: superior vena cava; IVC: inferior vena cava; AAo: ascending Aorta; RAA: right atrial auricle; RCA: right coronary artery; RV: right ventricle; STV: tricuspid valve; CS/ ThV: coronary sinus and Thebesian valve; TT: Tendon of Todaro; OF: Foramen ovale; ER/EV: Eustachian ridge and valve; crista terminalis.