Abstract

One each of 17 commercially available prosthetic mitral valves has been subjected to in vitro testing using a pulse duplicator. Measurements of mean diastolic pressure difference, incompetence, dimensions, mechanical movements, and turbulence were made, and the quality of manufacture was examined. Although most valves would be effective in the treatment of incompetence, only those with large orifice diameters produced no significant stenosis. All the valves tested were in clinical use at some time in the period 1966-71. Most of the prostheses were obtained in 1968 or 1969. Many of this group showed a manufacturing standard which was less than impeccable.