An unusual Doppler-echocardiographic finding in case of a Björk-Shiley mitral prosthetic valve thrombosis.

We report a patient in whom the commonly accepted Doppler echocardiographic findings failed to suggest prosthetic valve dysfunction. This was diagnosed by M-mode technique. We therefore feel that M-mode echocardiography still has its place in the complete evaluation of patients with suspected prosthetic valve dysfunction.