title: Proximal flow convergence method by three-dimensional color Doppler echocardiography for mitral valve area assessment in rheumatic mitral stenosis.
abstract: BACKGROUND
  The two-dimensional (2D) proximal isovelocity surface area (PISA) method has important technical limitations for mitral valve orifice area (MVA) assessment in mitral stenosis (MS), mainly the geometric assumptions of PISA shape and the requirement of an angle correction factor. Single-beat real-time three-dimensional (3D) color Doppler imaging allows the direct measurement of PISA without geometric assumptions or the requirement of an angle correction factor. The aim of this study was to validate this method in patients with rheumatic MS.
  
  
  METHODS
  Sixty-three consecutive patients with rheumatic MS were included. MVA was assessed using the transthoracic 2D and 3D PISA methods. Planimetry of MVA (2D and 3D) and the pressure half-time method were used as reference methods.
  
  
  RESULTS
  The 3D PISA method had better correlations with the reference methods (with 2D planimetry, r = 0.85, P < .001; with 3D planimetry, r = 0.89, P < .001; and with pressure half-time, r = 0.85, P < .001) than the conventional 2D PISA method (with 2D planimetry, r = 0.63, P < .001; with 3D planimetry, r = 0.66, P < .001; and with pressure half-time, r = 0.68, P < .001). In addition, a consistent significant underestimation of MVA using the conventional 2D PISA method was observed. A high percentage (30%) of patients with nonsevere MS by 3D planimetry were misclassified by the 2D PISA method as having severe MS (effective regurgitant orifice area < 1 cm(2)). In contrast, the 3D PISA method had 94% agreement with 3D planimetry. Good intra- and interobserver agreement for 3D PISA measurements were observed, with intraclass correlation coefficients of 0.95 and 0.90, respectively.
  
  
  CONCLUSIONS
  MVA assessment using PISA by single-beat real-time 3D color Doppler echocardiography is feasible in the clinical setting and more accurate than the conventional 2D PISA method.
authors.affiliation: Instituto Cardiovascular, Unidad de Imagen Cardiaca, Hospital Universitario San Carlos, Madrid, Spain. Electronic address: albertutor@hotmail.com.
authors.forename: Jose Alberto
authors.initials: JA
authors.lastname: de Agustin
authors.affiliation: Instituto Cardiovascular, Unidad de Imagen Cardiaca, Hospital Universitario San Carlos, Madrid, Spain.
authors.forename: Hernan
authors.initials: H
authors.lastname: Mejia
authors.affiliation: Instituto Cardiovascular, Unidad de Imagen Cardiaca, Hospital Universitario San Carlos, Madrid, Spain.
authors.forename: Dafne
authors.initials: D
authors.lastname: Viliani
authors.affiliation: Instituto Cardiovascular, Unidad de Imagen Cardiaca, Hospital Universitario San Carlos, Madrid, Spain.
authors.forename: Pedro
authors.initials: P
authors.lastname: Marcos-Alberca
authors.affiliation: Instituto Cardiovascular, Unidad de Imagen Cardiaca, Hospital Universitario San Carlos, Madrid, Spain.
authors.forename: Jose Juan
authors.initials: JJ
authors.lastname: Gomez de Diego
authors.affiliation: Instituto Cardiovascular, Unidad de Imagen Cardiaca, Hospital Universitario San Carlos, Madrid, Spain.
authors.forename: Ivan Javier
authors.initials: IJ
authors.lastname: Nuñez-Gil
authors.affiliation: Instituto Cardiovascular, Unidad de Imagen Cardiaca, Hospital Universitario San Carlos, Madrid, Spain.
authors.forename: Carlos
authors.initials: C
authors.lastname: Almeria
authors.affiliation: Instituto Cardiovascular, Unidad de Imagen Cardiaca, Hospital Universitario San Carlos, Madrid, Spain.
authors.forename: Jose Luis
authors.initials: JL
authors.lastname: Rodrigo
authors.affiliation: Instituto Cardiovascular, Unidad de Imagen Cardiaca, Hospital Universitario San Carlos, Madrid, Spain.
authors.forename: Maria
authors.initials: M
authors.lastname: Luaces
authors.affiliation: Instituto Cardiovascular, Unidad de Imagen Cardiaca, Hospital Universitario San Carlos, Madrid, Spain.
authors.forename: Miguel Angel
authors.initials: MA
authors.lastname: Garcia-Fernandez
authors.affiliation: Instituto Cardiovascular, Unidad de Imagen Cardiaca, Hospital Universitario San Carlos, Madrid, Spain.
authors.forename: Carlos
authors.initials: C
authors.lastname: Macaya
authors.affiliation: Instituto Cardiovascular, Unidad de Imagen Cardiaca, Hospital Universitario San Carlos, Madrid, Spain.
authors.forename: Leopoldo
authors.initials: L
authors.lastname: Perez de Isla
mesh_terms: D000368:Aged; D001783:Blood Flow Velocity / Q000502:physiology*; D018618:Echocardiography, Doppler, Color / Q000379:methods*; D019560:Echocardiography, Three-Dimensional / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008943:Mitral Valve / Q000000981:diagnostic imaging*; D008946:Mitral Valve Stenosis / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology; D011446:Prospective Studies; D015203:Reproducibility of Results; D012214:Rheumatic Heart Disease / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology; D012720:Severity of Illness Index
keywords: Mitral stenosis; Proximal isovelocity surface area; Three-dimensional echocardiography