Assessment of Björk-Shiley and porcine mitral valve dysfunction by m-mode echocardiographic left ventricular dimension.

In this study of 46 patients with mitral valve prostheses, we report on the accuracy of the left ventricular maximum filling velocity (LVMFV) index as a diagnostic tool for valve dysfunction. Echocardiographic left ventricular internal dimensions were measured every 0.05 seconds, and every measure was transferred to an axis system. The tangent to this curve was traced at the point of maximum rate of increase of dimension, and the slope in mm/sec represents the LVMFV index. Six patients, each with an obstructed mitral valve prosthesis, had a reduced LVMFV index (p < 0.001). On the other hand, eight patients with a paravalvular leak showed a LVMFV index significantly higher (p < 0.05) than patients with a normally functioning mitral valve prosthesis. The results of this study suggest that analysis of the LVMFV index can be a useful and reliable substitute for other noninvasive diagnostic techniques in evaluating certain patients with suspected prosthetic mitral valve malfunction.