title: Distant Position of Chordae from Coaptation Causes Mitral Regurgitation in Patients with Atrial Fibrillation.
abstract: The study aim was to investigate the mechanism of mitral regurgitation (MR) in lone atrial fibrillation (AF) patients using three-dimensional (3D) transesophageal echocardiography (TEE).
  
  
  
  A retrospective analysis was conducted of 64 patients with AF and a normal left ventricle, and without prolapse of the mitral valve. Among these patients, significant MR was not identified in 33 cases (AF+MR- group) but was present in 31 cases (AF+MR+ group). The distance from the coaptation to the bending point of the anterior mitral leaflet (AML), where the chorda was attached, was termed the 'bending length'. The ratio of the bending length to the distance from coaptation to anterior mitral annulus was termed the 'bending ratio' (= bending length/coaptation-annulus length). The mitral annular area (MAA) fractional change was defined as follows: (MAA at late systole - MAA at early systole)/MAA at late systole × 100%). Other parameters relating to mitral valve morphology obtained using 3D TEE were measured with commercial software (QLAB, Phillips).
  
  
  
  The coaptation length (CL) was smaller in the AF+MR+ group than in the AF+MR- group (p<0.001), and correlated significantly with the anteriorposterior diameter of the mitral annulus (R = 0.286, p = -0.022), MAA at mid-systole (R = -0.269, p = 0.032), MAA fractional change (R = 0.434, p <0.001), and the bending ratio (R = -0.603, p <0.001). With a multivariable analysis, the correlating factors of significant MR in lone AF patients were a decrease in MAA fractional change (p = 0.022) and an increase of the bending ratio (p = 0.009).
  
  
  
  Small MAA fractional changes and the distant position of the chordae tendineae on the AML from the coaptation correlated with significant MR in AF patients with normal left ventricular systolic function.
authors.affiliation: Noninvasive Cardiac Laboratory, Cedars-Sinai Heart Institute, Los Angeles, CA, USA.|Department of Cardiology, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Itabashi
authors.affiliation: Noninvasive Cardiac Laboratory, Cedars-Sinai Heart Institute, Los Angeles, CA, USA.
authors.forename: Hirotsugu
authors.initials: H
authors.lastname: Mihara
authors.affiliation: Noninvasive Cardiac Laboratory, Cedars-Sinai Heart Institute, Los Angeles, CA, USA.
authors.forename: Javier
authors.initials: J
authors.lastname: Berdejo
authors.affiliation: Noninvasive Cardiac Laboratory, Cedars-Sinai Heart Institute, Los Angeles, CA, USA.
authors.forename: Hiroto
authors.initials: H
authors.lastname: Utsunomiya
authors.affiliation: Noninvasive Cardiac Laboratory, Cedars-Sinai Heart Institute, Los Angeles, CA, USA. Electronic correspondence: Takahiro.Shiota@cshs.org.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Shiota
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation / Q000150:complications* / Q000000981:diagnostic imaging / Q000503:physiopathology; D002815:Chordae Tendineae / Q000503:physiopathology*; D019560:Echocardiography, Three-Dimensional; D017548:Echocardiography, Transesophageal; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012307:Risk Factors