title: Left ventricular rotation and twist assessed by four-dimensional speckle tracking echocardiography in healthy subjects and pathological remodeling: a single center experience.
abstract: BACKGROUND
  Left ventricular (LV) twist represents a main aspect of ejection. It is defined as the difference between the apical and basal rotation and can be assessed by speckle tracking echocardiography (STE). Twist may be underestimated when assessed by two-dimensional-echocardiography due to the difficulty of identifying the real apex. Aim of this study was to evaluate the LV twist by means of three-dimensional (3D)-STE and verify if the inclusion of the apex can modify the assessment of the global twist.
  
  
  METHODS
  LV volume acquisition with a fully sampled matrix array transducer was performed in 30 healthy subjects and 79 patients with cardiomyopathy secondary to different etiologies. Thirty-nine patients had a LV ejection fraction (EF) ≥50% (Group A), 16 showed an EF between 40 and 50% (Group B), and 24 patients had an EF ≤40%(Group C). LV rotation was assessed by 3D-STE at basal, medium, apical, and apical-cap levels. Twist was computed considering the apex either at the apical level (Twist(Api) ) or at the apical-cap level (Twist(AC) ).
  
  
  RESULTS
  LV rotation resulted to be progressively higher from base to apical-cap (P < 0.0001) with a significant difference between the apex and the apical-cap level (6.20 ± 3.90° vs. 10.23 ± 7.52°; P < 0.001). Such a difference was constantly found in all Groups (P < 0.01 for Group A, P < 0.05 for Group B and C). Twist(Api) was also significantly lower than Twist(AC) both in the overall population (6.2 ± 3.89° vs. 10.23 ± 7.51°; P < 0.001) and in the different subgroups (
  
  
  METHODS
  9.61 ± 3.39° vs. 13.75 ± 6.51°; Group A: 10.49 ± 4.77° vs. 16.37 ± 8.49°; Group B: 6.67 ± 3.44° vs. 9.14 ± 5.55°; Group C: 33 ± 2.62° vs. 5.26 ± 3.74°; P < 0.05 for all the comparisons).
  
  
  CONCLUSIONS
  Identification and inclusion of apical-cap is relevant for twist assessment and can be carried out efficiently by 3D-STE. The inclusion of the true apex in the calculation significantly affects the analysis of twist both in normal individuals and patients with different myocardial diseases.
authors.affiliation: Emergency Department, UO Cardiology, Versilia Hospital, Lido di Camaiore, Italy. lilli.alessio@libero.it
authors.forename: Alessio
authors.initials: A
authors.lastname: Lilli
authors.forename: Marco Tullio
authors.initials: MT
authors.lastname: Baratto
authors.forename: Jacopo
authors.initials: J
authors.lastname: Del Meglio
authors.forename: Marco
authors.initials: M
authors.lastname: Chioccioli
authors.forename: Massimo
authors.initials: M
authors.lastname: Magnacca
authors.forename: Enrica
authors.initials: E
authors.lastname: Talini
authors.forename: Maria Laura
authors.initials: ML
authors.lastname: Canale
authors.forename: Rosa
authors.initials: R
authors.lastname: Poddighe
authors.forename: Alessandro
authors.initials: A
authors.lastname: Comella
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Casolo
mesh_terms: D000368:Aged; D019561:Echocardiography, Four-Dimensional / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006352:Heart Ventricles / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000502:physiology*; D012189:Retrospective Studies; D013318:Stroke Volume / Q000502:physiology*; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000503:physiopathology; D016277:Ventricular Function, Left; D020257:Ventricular Remodeling