Distinguishing Fluoroscopic Features of Bjork–Shiley Convexoconcave and Spherical Heart-Valve Prostheses

To the Editor: With the recent adverse publicity concerning the Bjork–Shiley convexoconcave heart-valve prosthesis,¹ it may be important that physicians be able to identify easily the type of Bjork–Shiley valve implanted in their patients. Many patients, unfortunately, do not carry papers for proper valve identification, and hospital records may not be accessible. As noted previously, the radiographic silhouette of the Bjork–Shiley convexoconcave heart-valve prosthesis on the plain chest film appears similar to that of the Bjork–Shiley spherical-disk valve.² If the valves are examined cinefluoroscopically, however, several distinguishing features may be noted. Figure 1 shows x-ray silhouettes of the convexoconcave-disk mitral valve on.