Obstructive Characteristics of Björk‐Shiley, Hancock, and Lillehei‐Kaster Prosthetic Mitral Valves in the Immediate Postoperative Period

Abstract

The flow obstruction in mitral valve implants was studied in the immediate postoperative period in 19 patients with Björk-Shiley, Hancock, or Lillehei-Kaster prosthetic mitral valves. The effective valve area (A_e) was used as a measure of the flow obstruction. The blood velocity in the implants was estimated with a non-invasive ultrasound Doppler system. The cardiac output was determined with an indwelling thermodilution catheter. The collected data allowed the determination of A_e. Multiple determinations of A_e, at various cardiac outputs and pulse rates were generally performed in each patient during the first 2–3 postoperative days. The investigation demonstrated that the method employed was useful for the study of mitral implant performance. The obtained values of A_e demonstrated that the flow obstruction in prosthetic mitral valve implants is fiequently considerable.