Echocardiography after mitral valve replacement and criteria of paraprosthetic regurgitation.

19 patients with Björk-Shiley mitral tilting disc valve prostheses were studied by echocardiography before the valve replacement operation and postoperatively every three months up to one year. In 14 patients with normal prosthetic function the left atrial diameter decreased markedly after operation (p less than 0.001), but echocardiographic dimensional indices of left ventricular performance remained unchanged. Paradoxical or markedly hypokinetic motion of the interventricular septum was observed within 3 months of operation in 46% of the patients, but in only 28% in studies performed 9 - 12 months after the replacement. The ampliture of the disc was on average 11 +/- 2 mm. In 5 patients with paraprosthetic regurgitation the left atrial diameter increased with the development of regurgitation and decreased again after successful reoperation. In these patients the left ventricular end diastolic and stroke volumes were great (p less than o.01) than in patients with normal prostheses. The septal motion was in the normal direction in all these 5 patients and the septal amplitudes were greater (p less than 0.01) than in the patients with normal prostheses. The amplitudes of the disc were normal, but abnormal anterior movement of the disc at the beginning of the diastole was observed. These data demonstrate that echocardiography is useful in the diagnosis of paraprosthetic mitral valve regurgitation.