title: Dynamic assessment of the changing geometry of the mitral apparatus in 3D could stratify abnormalities in functional mitral regurgitation and potentially guide therapy.
abstract: BACKGROUND
  In functional mitral regurgitation (FMR), effective regurgitant orifice area (EROA) displays a dynamic pattern. The impact of dynamic changes of annulus dysfunction and leaflets tenting on phasic EROA was explored with real-time three-dimensional transesophageal echocardiography (RT3D-TEE).
  
  
  METHODS
  RT3D-TEE was performed in 52 FMR patients and 30 controls. Mitral annulus dimensions and leaflets tenting were measured throughout systole (TomTec, Germany). Phasic EROA was measured by proximal isovelocity surface area (PISA) method.
  
  
  RESULTS
  Mitral annulus had the minimal area and an oval shape with saddle configuration during early systole in controls, which enlarged and became round and flattened towards mid and late systole (P<0.05). In contrast, annulus in FMR was significantly larger, rounder and flatter (P<0.001), which further dilated and became more flattened at late systole (P<0.05 vs control). Leaflet tenting height in FMR decreased in mid systole and remains unchanged towards late systole. The leaflet tenting volume peaked at early and late systole with a mid-systolic trough in both FMR and controls. But tenting volume of patients with FMR was significantly larger than that of controls (all P<0.001 vs control in whole systole). Further analysis demonstrated that early tenting volume (β value=0.053, P<0.05) was a predictor of early EROA, whereas late tenting volume (β value=0.031, P<0.05) and late annular displacement velocity were predictors of late EROA.
  
  
  CONCLUSIONS
  The early and late peak EROAs of FMR was primarily contributed by tenting volume at early systole and late systole respectively. These findings would be of value to consider in interventions aimed at reducing the severity of FMR.
authors.affiliation: Institute of Vascular Medicine, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Qing-shan
authors.initials: QS
authors.lastname: Lin
authors.affiliation: Institute of Vascular Medicine, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Fang
authors.initials: F
authors.lastname: Fang
authors.affiliation: Institute of Vascular Medicine, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Cheuk-man
authors.initials: CM
authors.lastname: Yu
authors.affiliation: Institute of Vascular Medicine, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Yan-Chao
authors.initials: YC
authors.lastname: Zhang
authors.affiliation: Division of Cardiology, Heart Center, Cheng-Hsin General Hospital, Faculty of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Ming C
authors.initials: MC
authors.lastname: Hsiung
authors.affiliation: Philips Healthcare, Andover, MA, United States.
authors.forename: Ivan S
authors.initials: IS
authors.lastname: Salgo
authors.affiliation: Institute of Vascular Medicine, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Jen-Li
authors.initials: JL
authors.lastname: Looi
authors.affiliation: Division of Cardiothoracic Surgery, Department of Surgery, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Song
authors.initials: S
authors.lastname: Wan
authors.affiliation: Division of Cardiothoracic Surgery, Department of Surgery, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Randolph H L
authors.initials: RH
authors.lastname: Wong
authors.affiliation: Division of Cardiothoracic Surgery, Department of Surgery, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Malcom J
authors.initials: MJ
authors.lastname: Underwood
authors.affiliation: Institute of Vascular Medicine, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Jun-Ping
authors.initials: JP
authors.lastname: Sun
authors.affiliation: Division of Cardiothoracic Surgery, Department of Surgery, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Wei-Hsian
authors.initials: WH
authors.lastname: Yin
authors.affiliation: Division of Cardiothoracic Surgery, Department of Surgery, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Jeng
authors.initials: J
authors.lastname: Wei
authors.affiliation: Institute of Vascular Medicine, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Chun-na
authors.initials: CN
authors.lastname: Jin
authors.affiliation: Division of Cardiothoracic Surgery, Department of Surgery, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Shen-Kou
authors.initials: SK
authors.lastname: Tsai
authors.affiliation: Institute of Vascular Medicine, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Ling
authors.initials: L
authors.lastname: Ji
authors.affiliation: Institute of Vascular Medicine, The Chinese University of Hong Kong, Hong Kong. Electronic address: alexpwlee@cuhk.edu.hk.
authors.forename: Alex Pui-Wai
authors.initials: AP
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D019560:Echocardiography, Three-Dimensional / Q000379:methods* / Q000639:trends*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging*; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging*
keywords: Functional mitral regurgitation; Real-time 3-dimensional transesophageal echocardiography; Tenting volume