title: Assessment of left atrial mechanics in patients with atrial fibrillation: comparison between two-dimensional speckle-based strain and velocity vector imaging.
abstract: BACKGROUND
  Two-dimensional (2D) speckle tracking-derived left atrial (LA) strain (ε) facilitates comprehensive evaluation of LA contractile, reservoir, and conduit function; however, its dependence on the individual software used for assessment has not been evaluated. The aim of this study was to compare LA ε derived from two different speckle-tracking software technologies, Velocity Vector Imaging (VVI) and 2D speckle-tracking echocardiography (STE).
  
  
  METHODS
  VVI-derived and 2D STE-derived global longitudinal LA ε and ε rate (SR) were directly compared in 127 patients (mean age, 62 ± 10 years) with atrial fibrillation. Peak negative, peak positive, and total ε (corresponding to LA contractile, conduit, and reservoir function) were measured during sinus rhythm. Late negative (LA contraction), peak positive (left ventricular systole), and early negative (left ventricular early diastole) SR were also measured.
  
  
  RESULTS
  The measurement of LA ε and SR by both software was feasible in high proportions of patients (93% with VVI and 93% with 2D STE). The average analysis of ε(negative) was -7.24 ± 3.87% by VVI and -7.30 ± 3.37% by 2D STE (P = .84). The average analysis of ε(positive) was 14.52 ± 5.82% by VVI and 10.74 ± 4.51% by 2D STE (P < .01). The average analysis of ε(total) was 21.76 ± 7.39% by VVI and 18.04 ± 5.98% by 2D STE (P < .01). VVI-derived and 2D STE-derived ε(positive), ε(negative), and ε(total) had good correlations with one another (R = 0.79, R = 0.75, and R = 0.80), with low mean differences. Late negative, peak positive, and early negative SR were correlated less well (R = 0.78, R = 0.71, and R = 0.67).
  
  
  CONCLUSIONS
  LA ε measurement using both VVI and 2D STE is feasible in a large proportion of patients in clinical practice. VVI and 2D STE provide comparable LA ε and SR measurements for LA contractile function.
authors.affiliation: Department of Cardiovascular Medicine, Heart and Vascular Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, USA.
authors.forename: Hirohiko
authors.initials: H
authors.lastname: Motoki
authors.forename: Arun
authors.initials: A
authors.lastname: Dahiya
authors.forename: Mandeep
authors.initials: M
authors.lastname: Bhargava
authors.forename: Oussama M
authors.initials: OM
authors.lastname: Wazni
authors.forename: Walid I
authors.initials: WI
authors.lastname: Saliba
authors.forename: Thomas H
authors.initials: TH
authors.lastname: Marwick
authors.forename: Allan L
authors.initials: AL
authors.lastname: Klein
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D016279:Atrial Function, Left / Q000502:physiology*; D004452:Echocardiography / Q000379:methods*; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006325:Heart Atria / Q000000981:diagnostic imaging*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008875:Middle Aged; D012984:Software