title: Impact of acoustic window on accuracy of longitudinal global strain: a comparison study to cardiac magnetic resonance.
abstract: OBJECTIVE
  To evaluate the impact of acoustic window on the feasibility and accuracy of longitudinal global strain (global-ε) by speckle tracking for assessing left ventricular (LV) systolic function.
  
  
  RESULTS
  The study included 70 patients (57 ± 17 years, 64% men), 28 selected patients with a suboptimal image quality (IQ) defined by three or more segments (4 ± 3 segments/patient) with wall motion score not analysable visually and 42 patients with an optimal two-dimensional (2D) echocardiography IQ. Left ventricular ejection fraction (LVEF) by Simpson's biplane method (2D-EF), global-ε by speckle tracking, and peak systolic mitral annulus velocity [systolic tissue Doppler imaging (S-TDI)] were compared with LVEF by cardiac magnetic resonance (EF-CMR; 45 ± 18%, range 9-76%). Speckle-tracking analysis was feasible in all segments with an optimal acoustic window and in 85% (103/121) of segments poorly visualized. Global-ε similarly correlated with LVEF by CMR in patients with and without optimal IQ (r = 0.81 vs. 0.82 for good vs. poor IQ). In contrast, 2D-EF (r = 0.76) and S-TDI (r = 0.64) less correlated with LVEF by CMR in patients with a suboptimal IQ. Importantly, IQ only impacted on 2D-EF inter-observer reproducibility (9 ± 5 vs. 24 ± 22% for good vs. poor IQ) but not on global-ε reproducibility (9 ± 1 vs. 8 ± 7% for good vs. poor IQ).
  
  
  CONCLUSIONS
  In patients with a limited acoustic window, longitudinal strain by speckle tracking remains accurate and reproducible for assessing global and regional LV systolic function.
authors.affiliation: Cardiovascular Department, APHP, Henri Mondor University Hospital, Creteil, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Macron
authors.forename: Olivier
authors.initials: O
authors.lastname: Lairez
authors.forename: Julien
authors.initials: J
authors.lastname: Nahum
authors.forename: Mathieu
authors.initials: M
authors.lastname: Berry
authors.forename: Leslie
authors.initials: L
authors.lastname: Deal
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Deux
authors.forename: Alexandre
authors.initials: A
authors.lastname: Bensaid
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Dubois Randé
authors.forename: Pascal
authors.initials: P
authors.lastname: Gueret
authors.forename: Pascal
authors.initials: P
authors.lastname: Lim
mesh_terms: D000704:Analysis of Variance; D015150:Echocardiography, Doppler; D019560:Echocardiography, Three-Dimensional; D005240:Feasibility Studies; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000295:instrumentation*; D008297:Male; D008875:Middle Aged; D013223:Statistics as Topic; D013599:Systole; D016277:Ventricular Function, Left / Q000502:physiology*