Where is the Eustachian valve located?

The Eustachian valve is located between the inferior vena cava and the right atrium. It is a remnant of embryonic development and plays a role in directing blood flow from the inferior vena cava toward the foramen ovale in the fetus. This anatomical structure is particularly relevant in fetal circulation, where it helps to shunt blood away from the non-functioning lungs.

In adults, the Eustachian valve may have diminished functional significance but can still be identified during echocardiography or cardiac imaging studies. Understanding this location is important for cardiac sonographers, as it is critical for proper interpretation of echocardiographic images and for understanding the flow patterns in right heart structures.