An Engineer's View of Prosthetic Heart Valve Performance

Abstract

A review is given that includes indications for surgical replacement of natural valves, basic types of prosthetic valves, a history of the development and application of prosthetic valves, and special problems of implantation. Medical considerations are discussed in the light of postoperative complications. Technical and engineering considerations are presented to outline the development and application stages of a typical prosthetic heart valve, materials used in fabrication, a qualitative comparison of materials, and comparison of ball and disk valves from several viewpoints. Performance of prosthetic valves is discussed from the standpoint of three basic questions: “For what reasons are prosthetic heart valves implanted?”, “How is performance defined?”, and “How is performance measured/evaluated?” In vitro flow performance is contrasted to in vivo performance. Some of the work done at the Jet Propulsion Laboratory is presented and discussed. In particular, the theoretical formulation for flow through an aortic prosthetic valve is described. Finally, a compilation of specifications for an ideal prosthetic heart valve is presented.