title: [A description of a new method of quantifying the regurgitant flow in patients with an incompetent mitral valve].
abstract: BACKGROUND
  It has been shown previously that using color Doppler flow mapping, simple measurements of apparent jet size do not correlate closely with regurgitant flow rate and regurgitant fraction. Recently the proximal flow convergence method has been proposed to quantify valvular regurgitation by analysis of the converging flow field proximal to a regurgitant lesion. Flow rate Q can be calculated as Q = 2 pi r2va where va is the aliasing velocity at a distance r from the orifice.
  
  
  METHODS
  In 54 patients (43 in sinus rhythm, 11 with atrial fibrillation) with at least mild mitral regurgitation by semi-quantitative assessment, regurgitant stroke volume, regurgitant flow rate, and regurgitant fraction were calculated using the proximal flow convergence method and compared with values obtained by the Doppler/two-dimensional echocardiographic method.
  
  
  RESULTS
  Regurgitant stroke volumes (VL) calculated by the proximal flow convergence method correlated very closely with values obtained by the Doppler-2D method with r = 0.93 (y = 0.95x + 0.55) and delta VL = -0.3 +/- 4.0 cm3. Regurgitant flow rates (Q) calculated by both methods showed a similar correlation: r = 0.93 (y = 0.95x + 54) and delta Q = -34 +/- 284 cm3/min. The correlation for regurgitant fraction (RF) calculated by both techniques showed r = 0.89 (y = 0.98x + 0.006) and delta RF = -0.005 +/- 0.06. All correlations were slightly better for the group of patients in sinus rhythm compared with the study group in atrial fibrillation.
  
  
  CONCLUSIONS
  This study demonstrates that the proximal flow convergence method is an accurate and reproducible technique to quantify mitral regurgitation. This approach is easy and less time-consuming than the Doppler-echocardiographic method. While future improvements of this method are to be expected, flow calculations based on the assumption of simple hemispheric symmetry of the proximal flow field appear suitable for clinical application at the present time.
authors.affiliation: Servicio de Cardiología, Massachusetts General Hospital, Harvard Medical School, Boston.
authors.forename: J M
authors.initials: JM
authors.lastname: Rivera
authors.forename: P M
authors.initials: PM
authors.lastname: Vandervoort
authors.forename: E
authors.initials: E
authors.lastname: Morris
authors.forename: J
authors.initials: J
authors.lastname: Marshall
authors.forename: T
authors.initials: T
authors.lastname: Joziatis
authors.forename: A E
authors.initials: AE
authors.lastname: Weyman
authors.forename: J D
authors.initials: JD
authors.lastname: Thomas
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001783:Blood Flow Velocity; D004452:Echocardiography / Q000379:methods / Q000706:statistics & numerical data; D015150:Echocardiography, Doppler / Q000379:methods* / Q000706:statistics & numerical data; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging / Q000503:physiopathology; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging* / Q000503:physiopathology; D015203:Reproducibility of Results
vernacular_title: Descripción de un nuevo método de cuantificación del flujo regurgitante en pacientes con válvula mitral incompetente.