Diagnosis of intermittent obstruction of mechanical mitral valve prostheses by Doppler echocardiography.

In summary, this is a report on 5 various malfunctioning mechanical monocuspid mitral prostheses in which Doppler demonstrated intermittent restriction to the prosthetic disc opening, resulting in intermittent obstruction. In all 5 patients, it was mainly this abnormal Doppler signal that alerted us to the presence of prosthetic valve malfunction. In the 3 asymptomatic patients, the variable and intermittent increased delay in prosthetic valve opening was shown to be an early and sensitive echocardiographic sign of prosthesis malfunction in the absence of any significant increase in pressure gradients.