title: Comparison between Doppler echocardiography and hot-film anemometry in measuring the turbulent shear stress downstream of artificial mitral valves: a methodological study.
abstract: BACKGROUND
  Turbulent shear stress (TSS) plays an important role in the research of fluid dynamics of heart valves. This study aimed to perform a quantitative study of TSS downstream of porcine artificial mitral valves in order to verify the correlation of hot-film anemometry (HFA) and Doppler echocardiography combined with computer-aided image analysis for the detection of TSS.
  
  
  METHODS
  A porcine model of mitral valve replacement was established. HFA and Doppler ultrasound techniques were used to directly and indirectly measure TSS-relevant parameters of the artificial mitral valve following different mitral valve replacements: different approaches were used to reserve the subvalvular apparatus of the mitral valve. A correlation analysis was then carried out.
  
  
  RESULTS
  There was a significant correlation between the HFA and Doppler ultrasound combined with computer-aided image analysis of the TSS at the same time and at the same site. No significant difference was found in the TSS measured by the two methods.
  
  
  CONCLUSIONS
  Compared with HFA, Doppler echocardiography combined with computer-aided image analysis is a safe, non-invasive, and real-time method that enables accurate and quantitative detection of TSS downstream in vivo, objectively reflecting the flow field downstream of the artificial mitral valve. Doppler ultrasound combined with computer-aided image analysis can be employed for quantitatively evaluating the downstream hemodynamic performance of the mitral valve.
authors.affiliation: Department of Cardiovascular Surgery, First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Sun
authors.forename: Rui-jie
authors.initials: RJ
authors.lastname: Li
authors.forename: Gan-niu
authors.initials: GN
authors.lastname: Li
authors.forename: Bin
authors.initials: B
authors.lastname: Li
authors.forename: Yu
authors.initials: Y
authors.lastname: Wang
authors.forename: Run-wei
authors.initials: RW
authors.lastname: Ma
authors.forename: Bai-hui
authors.initials: BH
authors.lastname: Yang
authors.forename: Sen-lin
authors.initials: SL
authors.lastname: Lu
authors.forename: Gui-min
authors.initials: GM
authors.lastname: Zhang
mesh_terms: D000818:Animals; D015150:Echocardiography, Doppler / Q000379:methods*; D006350:Heart Valve Prosthesis; D007091:Image Processing, Computer-Assisted; D008943:Mitral Valve / Q000000981:diagnostic imaging / Q000601:surgery*; D011673:Pulsatile Flow; D012212:Rheology; D013314:Stress, Mechanical; D013552:Swine