Prosthetic valves

Abstract

The first part of Chapter 13 outlines an approach to imaging different types of prosthetic valves, including a description of optimal views and potential pitfalls encountered when imaging mechanical and bioprosthetic valves in the aortic and mitral positions. Next, the techniques of haemodynamic assessment of prosthetic valves (pressure gradients, valve areas, pressure half-time) are described. Normal pressure gradients and calculated valve areas for selected valves are provided in tabular form. The concepts of pressure recovery and patient–prosthesis mismatch are explained. The features of prosthetic valve regurgitation (normal versus abnormal, transvalvular versus paravalvular) are then reviewed. In the final section, the causes of pathological stenosis and regurgitation are discussed, including thrombus formation, endocarditis, calcific degeneration, and valve dehiscence.