title: Early postoperative echocardiographic hemodynamic performance of the On-X prosthetic heart valve: a multicenter study.
abstract: OBJECTIVE
  This study aimed to investigate the early postoperative Doppler-derived hemodynamic results from the first patients receiving the On-XR prosthetic heart valve, a new bileaflet, pyrolytic carbon valve.
  
  
  METHODS
  Data were derived from 111 patients included in a 10-center international trial between September 1996 and December 1997.
  
  
  RESULTS
  The effective orifice area (EOA) for the valve, when implanted in the aortic position, ranged from 1.5 to 2.7 cm2 in 19 mm to 25 mm valves. The corresponding mean pressure gradients ranged from 11.8 to 7.6 mmHg. Mitral EOA was 2.3 cm2 for all sizes, these values being combined because the housing was identical for all mitral valves used in this study. The mitral mean gradient was 4.7 mmHg.
  
  
  CONCLUSIONS
  Early results of the study show the good hemodynamic performance of the On-X valve when implanted in the aortic or mitral positions.
authors.affiliation: Guy's Hospital, London, UK.
authors.forename: J
authors.initials: J
authors.lastname: Chambers
authors.forename: J L
authors.initials: JL
authors.lastname: Ely
mesh_terms: D000328:Adult; D000368:Aged; D001021:Aortic Valve / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D001672:Biocompatible Materials; D002244:Carbon; D015150:Echocardiography, Doppler; D005260:Female; D006349:Heart Valve Diseases / Q000000981:diagnostic imaging / Q000601:surgery*; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000379:methods; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D011184:Postoperative Period; D011379:Prognosis; D011474:Prosthesis Design; D016896:Treatment Outcome
chemical_list: D001672:Biocompatible Materials; C009139:pyrolytic carbon; D002244:Carbon