Intermittent Entrapment of a Prosthetic Mitral Valve Disc

A 42-year-old man had undergone mitral valve (MV) replacement 12 years earlier with the use of a CarboMedics bileaflet mechanical prosthesis (Sorin Biomedica). On a routine visit, he was asymptomatic, and cardiac auscultation revealed closing and opening MV clicks. A transthoracic echocardiogram with the use of a 2-beat acquisition protocol showed normal excursion of both MV discs (Figure 1; Movie I in the online-only Data Supplement). Spectral Doppler of transmitral flow indicated normal peak gradients; however, abnormalities in the Doppler signal were intermittently noted. Whereas some cardiac cycles showed normal disc motion with near-simultaneous opening clicks, other cycles demonstrated a delay in 1 opening click or a single rather than dual opening clicks (Figure 2). The beats with a single opening click were associated with significant prolongation of the transmitral pressure half-time suggestive of obstruction to flow. The abnormalities on spectral Doppler prompted us to reimage the MV over several cardiac cycles. Intermittent delay in the opening of 1 disc with periodic disc entrapment in a closed position was noted (Figure 3;Movie II in the online-only Data Supplement). Interrogation with color Doppler showed intermittent …