title: Echocardiographic description of the CarboMedics bileaflet prosthetic heart valve.
abstract: OBJECTIVE
  The aim of this study was to describe the echocardiographic appearance of the normal CarboMedics prosthesis in the aortic and mitral positions.
  
  
  BACKGROUND
  Echocardiography is the standard method of assessing prosthetic valves. However, new valve designs may still be marketed without an accompanying echocardiographic description. The CarboMedics prosthesis is in widespread use, but few noninvasive hemodynamic data have been published.
  
  
  METHODS
  Echocardiography was performed in 147 patients with a total of 96 normally functioning CarboMedics prostheses in the aortic position and 75 in the mitral position; in 24 patients, valves were implanted in both positions. The following variables were measured: peak and mean transvalvular velocities, peak and mean instantaneous gradient estimated from the modified Bernoulli equation, aortic acceleration slope, pressure half-time, transvalvular flow and effective orifice area using the continuity equation. Patterns of regurgitation were observed by transthoracic study in all valves and by transesophageal study in selected mitral valve prostheses.
  
  
  RESULTS
  For the aortic valve prostheses, estimated mean gradient ranged between 6 and 19 mm Hg. Effective area differed markedly among the anulus diameters (p < 0.001), with a mean value of 1 cm2 for the 19-mm valve and 2.6 cm2 for the 29-mm valve. For the mitral valve prostheses, mean gradient ranged from 3 to 7 mm Hg. There were a total of four washing leaks, one on either side of each pivotal point, and these lasted throughout systole or diastole. One jet was commonly more prominent than the other three.
  
  
  CONCLUSIONS
  The CarboMedics prosthesis offered relatively little resistance to forward flow except at small anulus diameters. The washing jets were prominent and would be easy to misdiagnose as a sign of paraprosthetic regurgitation.
authors.affiliation: Department of Cardiology, Guy's Hospital, London, England.
authors.forename: J
authors.initials: J
authors.lastname: Chambers
authors.forename: J
authors.initials: J
authors.lastname: Cross
authors.forename: P
authors.initials: P
authors.lastname: Deverall
authors.forename: E
authors.initials: E
authors.lastname: Sowton
mesh_terms: D001021:Aortic Valve; D001022:Aortic Valve Insufficiency / Q000000981:diagnostic imaging; D001783:Blood Flow Velocity / Q000502:physiology; D003326:Coronary Circulation / Q000502:physiology; D004452:Echocardiography; D015150:Echocardiography, Doppler; D005260:Female; D006350:Heart Valve Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging; D011474:Prosthesis Design; D011475:Prosthesis Failure