title: Left ventricular twist: comparison between two- and three-dimensional speckle-tracking echocardiography in healthy volunteers.
abstract: OBJECTIVE
  left ventricular (LV) twist is the result of clockwise rotation of the base and counterclockwise rotation of the apex. The aims of this study were to investigate the feasibility of the three-dimensional speckle-tracking echocardiography (3DSTE) to assess LV twist values and compare the data measured by two-dimensional speckle-tracking echocardiography (2DSTE) in a group of healthy volunteers.
  
  
  RESULTS
  fifty individuals were enrolled in the protocol. LV twist was defined as net difference between averaged 2DSTE apical (4 segments) and basal (6 segments) rotations. 3DSTE twist was obtained from the LV volumetric image and shown as the averaged global value of 16 segments. Time-to-peak by both techniques was also measured and compared. Significant differences between the two techniques were calculated using the paired Student t-test. P-values of <0.05 were considered significant. Reliable LV twist measurement was possible in 39 of 50 individuals (78%). 2DSTE twist mean peak value was 13.8 + 7.9° with a mean time-to-peak of 388.3 ± 152.3 ms and global 3DSTE twist mean peak value was 10.2 + 7.6° with a mean time-to-peak of 371.8 ± 127.5 ms. Peak LV twist values by 3DSTE was significantly smaller than by 2DSTE (P < 0.01) whereas time-to-peak results showed no significant difference.
  
  
  CONCLUSIONS
  3DSTE is feasible to assess LV twist deformation. Whereas further investigations using 3DSTE are needed to validate this promising technology, comparing 2DSTE and 3DSTE should be done with caution, as values for peak LV twist differ.
authors.affiliation: Cardiology, Hospital Sírio-Libanês, R. Adma Jafet, 91, São Paulo SP 01308-050, Brazil. jolandrade@uol.com.br
authors.forename: José
authors.initials: J
authors.lastname: Andrade
authors.forename: Luiz D
authors.initials: LD
authors.lastname: Cortez
authors.forename: Orlando
authors.initials: O
authors.lastname: Campos
authors.forename: Ana L
authors.initials: AL
authors.lastname: Arruda
authors.forename: Jairo
authors.initials: J
authors.lastname: Pinheiro
authors.forename: Luciana
authors.initials: L
authors.lastname: Vulcanis
authors.forename: Tiago S
authors.initials: TS
authors.lastname: Shiratsuchi
authors.forename: Roberto
authors.initials: R
authors.lastname: Kalil-Filho
authors.forename: Giovanni G
authors.initials: GG
authors.lastname: Cerri
mesh_terms: D000328:Adult; D004452:Echocardiography; D019560:Echocardiography, Three-Dimensional; D005240:Feasibility Studies; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D012399:Rotation; D016277:Ventricular Function, Left / Q000502:physiology*