title: In vitro 2D PIV measurements and related aperture areas of tricuspid bioprosthetic mitral valves at the beginning of diastole.
abstract: OBJECTIVE
  Besides ventricular parameters, the design and angular orientation of a prosthetic heart valve induce a specific flow field. The aim of this study was to know the inflow characteristics of a left ventricular model (LVM), investigating the behavior of tricuspid bioprosthetic mitral valves in terms of velocity profiles and related valve aperture areas at the beginning of diastole, under different conditions.
  
  
  METHODS
  3 heart rates (HRs) were established in the LVM and each mitral bioprosthesis (27 and 31 mm diameter) was installed in 2 orientations, rotated by 180° . For each experimental setup, 2-dimensional particle image velocimetry (2D PIV) measurements and simultaneous mitral valve (MV) area detection were obtained from 50 samples.
  
  
  RESULTS
  The results from the velocity profiles immediately downstream of mitral bioprostheses showed the influence of valve orientation for moderate HRs, although for a similar magnitude of mean velocity vectors. The geometries of MV open areas for each HR were similar regardless of valve orientation, except for the 27-mm valve at 90 beats per minute (bpm), and for the 31-mm valve at 60 bpm. Moreover, for each HR, similar percentages of valve open area were obtained regardless of MV nominal diameters.
  
  
  CONCLUSIONS
  In conclusion, the experimental setup for the 2D PIV measurements synchronized with the MV area detection was a useful tool for knowing the inflow characteristics of the LVM.
authors.affiliation: Escola Politécnica of the University of São Paulo, São Paulo - Brazil.
authors.forename: Ovandir
authors.initials: O
authors.lastname: Bazan
authors.affiliation: Escola Politécnica of the University of São Paulo, São Paulo - Brazil.
authors.forename: Jayme Pinto
authors.initials: JP
authors.lastname: Ortiz
authors.affiliation: Escola Politécnica of the University of São Paulo, São Paulo - Brazil.
authors.forename: Newton Kiyoshi
authors.initials: NK
authors.lastname: Fukumasu
authors.affiliation: Escola Politécnica of the University of São Paulo, São Paulo - Brazil.
authors.forename: Antonio Luiz
authors.initials: AL
authors.lastname: Pacifico
authors.affiliation: Escola Politécnica of the University of São Paulo, São Paulo - Brazil.
authors.forename: Jurandir Itizo
authors.initials: JI
authors.lastname: Yanagihara
mesh_terms: D001705:Bioprosthesis; D003971:Diastole / Q000502:physiology*; D006350:Heart Valve Prosthesis; D006352:Heart Ventricles / Q000503:physiopathology; D006801:Humans; D008943:Mitral Valve / Q000503:physiopathology; D008955:Models, Cardiovascular; D011474:Prosthesis Design; D012212:Rheology; D014261:Tricuspid Valve / Q000503:physiopathology