title: Assessment of subendocardial vs. subepicardial left ventricular rotation and twist using two-dimensional speckle tracking echocardiography: comparison with tagged cardiac magnetic resonance.
abstract: OBJECTIVE
  The aim of this article is to evaluate the accuracy and reproducibility of two-dimensional speckle tracking echocardiography (2D-STE) for the estimation of left ventricular (LV) twist, using tagged cardiac magnetic resonance (cMR) as the reference standard, and to assess how much 2D-STE rotational parameters are affected by the level at which measurements are made within the LV.
  
  
  RESULTS
  Forty-three patients with various heart diseases and 10 healthy volunteers underwent cMR and 2D-STE on the same day. With both methods, basal and apical time-rotation curves were generated at endocardial, midwall, and epicardial levels. By using the most apical cMR short-axis cross-section as a comparator, apical rotation was significantly underestimated by 2D-STE. When 2D-STE and cMR short-axis cross-sections were matched for their internal dimensions, measurements of endocardial, midwall, and epicardial twists no longer differ between cMR and 2D-STE (12.6 +/- 5.9 vs. 12.5 +/- 5.7 degrees , 10.5 +/- 4.6 vs. 9.7 +/- 4.1 degrees , and 8.9 +/- 4.0 vs. 8.4 +/- 3.7 degrees , respectively, all P = ns).
  
  
  CONCLUSIONS
  Compared with tagged cMR, 2D-STE underestimates apical rotation and LV twist. This is related to the inability of 2D-STE to image the real LV apex in most of the patients. However, when 2D-STE and cMR data are compared at similar acquisition levels, both techniques provide similar values.
authors.affiliation: Division of Cardiology, Cliniques Universitaires Saint-Luc, Université Catholique de Louvain, Brussels, Belgium.
authors.forename: Céline
authors.initials: C
authors.lastname: Goffinet
authors.forename: Fabien
authors.initials: F
authors.lastname: Chenot
authors.forename: Annie
authors.initials: A
authors.lastname: Robert
authors.forename: Anne-Catherine
authors.initials: AC
authors.lastname: Pouleur
authors.forename: Jean-Benoît
authors.initials: JB
authors.lastname: le Polain de Waroux
authors.forename: David
authors.initials: D
authors.lastname: Vancrayenest
authors.forename: Olivier
authors.initials: O
authors.lastname: Gerard
authors.forename: Agnès
authors.initials: A
authors.lastname: Pasquet
authors.forename: Bernhard L
authors.initials: BL
authors.lastname: Gerber
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Vanoverschelde
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006331:Heart Diseases / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results; D012399:Rotation; D013318:Stroke Volume; D014463:Ultrasonography; D016277:Ventricular Function, Left; D055815:Young Adult