[Prominent Eustachian valve mimicking a right atrial mass]

Area of Science:

• Cardiology
• Embryology
• Anatomy

Background:

• The Eustachian valve (valvula venae cavae inferior) is an endocardial fold, an embryogenic remnant of the inferior vena cava.
• It plays a role in fetal circulation by directing blood flow through the patent foramen ovale.
• Postnatally, it typically regresses but can persist as a clinically significant anatomical variation.

Observation:

• Echocardiography is the gold standard for visualizing the Eustachian valve.
• Diagnostic challenges include mistaking the valve for cardiac masses like thrombi, vegetations, or tumors.
• A prominent Eustachian valve was previously misdiagnosed as an endocardial cyst in this case.

Findings:

• Integrated echocardiography, including transthoracic, transesophageal, and 3D reconstructions, accurately diagnosed a prominent Eustachian valve.
• The study precisely defined the anatomy and dynamics (kinesis) of this prominent valve.
• This case highlights the importance of advanced imaging in differentiating Eustachian valve from other intracardiac structures.

Implications:

• Accurate diagnosis of the Eustachian valve is clinically relevant for managing patent foramen ovale (PFO).
• Redundant Eustachian valves can interfere with the placement of devices like the Amplatzer PFO occluder.
• Correct identification prevents misdiagnosis and ensures appropriate patient management, especially in cases of suspected infective endocarditis.