title: Factors influencing pulmonary venous flow velocity patterns in mitral regurgitation: an in vitro study.
abstract: OBJECTIVE
  The aim of this study was to investigate factors affecting pulmonary venous flow patterns in mitral regurgitation.
  
  
  BACKGROUND
  Although pulmonary venous flow velocity patterns have been reported to be helpful in assessing the severity of mitral regurgitation, the influence of regurgitant jet direction, pulmonary venous location and left atrial pressures on pulmonary venous flow patterns has yet to be clarified.
  
  
  METHODS
  The mitral regurgitant jet was produced by a pulsatile piston pump at 10, 30 and 40 ml/beat through a circular orifice, whereas the pulmonary venous flow was driven by gravity. Four different patterns of pulmonary venous flow and mitral regurgitation were examined. The V wave pressure was set at 10, 30 and 50 mm Hg and pulmonary venous flow velocity at 30 cm/s. Color and pulsed Doppler recordings were obtained with a VingMed 800 scanner interfaced with a computer facilitating digital analysis.
  
  
  RESULTS
  The decrease in the velocity time integral of pulmonary venous flow was more prominent for any given volume of mitral regurgitation at higher left atrial pressure. When the mitral regurgitant jet was directed toward the pulmonary vein, a more prominent decrease in the velocity time integral was seen, especially for severe mitral regurgitation (40 ml) with high left atrial pressure (95% vs. 55%, p < 0.001); and the time to peak deceleration of forward flow was significantly shorter (485 vs. 523 ms, respectively, p < 0.01). Also, two different types (laminar and turbulent) of reversed pulmonary venous flow were observed.
  
  
  CONCLUSIONS
  Multiple factors, including jet direction, mitral regurgitant volume and left atrial pressure, determine the effect of mitral regurgitation on pulmonary venous flow velocity patterns.
authors.affiliation: Clinical Care Center for Congenital Heart Disease, Oregon Health Sciences University, Portland 97201-3098, USA.
authors.forename: A
authors.initials: A
authors.lastname: Passafini
authors.forename: T
authors.initials: T
authors.lastname: Shiota
authors.forename: M
authors.initials: M
authors.lastname: Depp
authors.forename: J
authors.initials: J
authors.lastname: Paik
authors.forename: S
authors.initials: S
authors.lastname: Ge
authors.forename: R
authors.initials: R
authors.lastname: Shandas
authors.forename: D J
authors.initials: DJ
authors.lastname: Sahn
mesh_terms: D001783:Blood Flow Velocity; D001794:Blood Pressure; D066298:In Vitro Techniques; D008944:Mitral Valve Insufficiency / Q000503:physiopathology*; D008954:Models, Biological; D011667:Pulmonary Veins / Q000503:physiopathology*; D011673:Pulsatile Flow