title: Value of mitral valve tenting volume determined by real-time three-dimensional echocardiography in patients with functional mitral regurgitation.
abstract: This study sought to evaluate mitral valve tenting volume (TnV) as a clinical parameter using real-time 3-dimensional echocardiography in patients with functional mitral regurgitation (MR). In 27 patients with functional MR and 4 controls without mitral disease, real-time 3-dimensional echocardiographic images were obtained to measure TnV frame by frame from presystole to end-systole. The maximal and minimal TnVs during systole were identified in each patient, and mitral annular areas and tenting heights were also measured. Using 2-dimensional echocardiography, tenting area (TnA) was measured from the apical long-axis, apical 4-chamber, and apical 2-chamber views. The regurgitant orifice area was measured by the proximal isovelocity surface area method. Maximal and minimal TnVs occurred at the time of 2 +/- 6% and 78 +/- 6% of whole systolic duration, respectively, and the systolic percentage change of TnV was related to that of tenting height but not to that of mitral annular area. TnA on the long-axis images was significantly larger than that on the 4- and 2-chamber images (2.5 +/- 1.4 vs 1.7 +/- 1.3 and 1.9 +/- 1.4 cm(2), respectively, p <0.001). Regurgitant orifice area was significantly correlated with maximal TnV (r = 0.90), minimal TnV (r = 0.86), and TnA on the long-axis (r = 0.79), 4-chamber (r = 0.75), and 2-chamber (r = 0.73) images. Among minimal TnV and 3 TnAs, minimal TnV was the only independent determinant of regurgitant orifice area (p <0.001). Minimal TnV >or=3.90 ml identified significant functional MR with a sensitivity of 86% and a specificity of 100%. In conclusion, TnV derived from real-time 3-dimensional echocardiography is a preferable novel single index for assessing mitral valve tethering in functional MR to TnA that is dependent on the location of 2-dimensional planes.
authors.affiliation: Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
authors.forename: Jong-Min
authors.initials: JM
authors.lastname: Song
authors.forename: Shota
authors.initials: S
authors.lastname: Fukuda
authors.forename: Takashi
authors.initials: T
authors.lastname: Kihara
authors.forename: Mi-Seung
authors.initials: MS
authors.lastname: Shin
authors.forename: Mario J
authors.initials: MJ
authors.lastname: Garcia
authors.forename: James D
authors.initials: JD
authors.lastname: Thomas
authors.forename: Takahiro
authors.initials: T
authors.lastname: Shiota
mesh_terms: D001783:Blood Flow Velocity / Q000502:physiology; D019560:Echocardiography, Three-Dimensional / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008944:Mitral Valve Insufficiency / Q000175:diagnosis / Q000000981:diagnostic imaging*; D009200:Myocardial Contraction / Q000502:physiology*; D015588:Observer Variation