Severe Functional Tricuspid Stenosis Due to Phosphoglyceride Crystal Deposition Disease in Right Atrium

This case report concerns a 72-year-old-female with severe functional tricuspid stenosis due to phosphoglyceride crystal deposition disease and a history of atrial septum closure and tricuspid valvuloplasty. Phosphoglyceride crystal deposition disease is extremely rare, and percutaneous transcatheter biopsy under intracardiac echocardiographic guidance proved to be useful for its diagnosis. (Level of Difficulty: Advanced.).