title: Does accessory pathway significantly alter left ventricular twist/torsion? A study in Wolff-Parkinson-White syndrome by velocity vector imaging.
abstract: BACKGROUND
  The aim of this study was to determine the impact of manifest accessory pathway on left ventricle (LV) twist physiology in Wolff-Parkinson-White (WPW) patients. Although this issue was addressed in 1 study based on speckle tracking method, there was no comparative study with a different technique. We planned to use velocity vector imaging (VVI) to find out how much an accessory pathway can affect LV twist mechanics.
  
  
  METHODS
  Thirty patients were enrolled regarding inclusion and exclusion criteria. Two serial comprehensive transthoracic echocardiography evaluations were performed before and after radiofrequency catheter ablation (RFCA) within 24 hours. Stored cine loops were analyzed using VVI technique and LV twist and related parameters were extracted.
  
  
  RESULTS
  Comparing pre- and post-RFCA data, no significant changes were observed in LV systolic and diastolic dimensions, LV ejection fraction (LVEF), and Doppler and tissue Doppler-related parameters. VVI study revealed remarkable rise in peak LV apical rotation (10.3º ± 3.0º to 13.8º ± 3.6º, P < 0.001) and basal rotation (-6.0 ± 1.8º to -7.7 ± 1.8º, P < 0.001) after RFCA. Subsequently LV twist showed a surge from 14.7º ± 3.9º to 20.2º ± 4.4º (P < 0.001). LV untwisting rate changed significantly from -96 ± 67 to -149.0 ± 47.5°/sec (P < 0.001) and apical-basal rotation delay showed a remarkable decline after RFCA (106 ± 81 vs. 42.8 ± 26.0 msec, P < 0.001).
  
  
  CONCLUSIONS
  Accessory pathways have a major impact on LV twist mechanics.
authors.affiliation: Razavi Hospital, Mashad, Iran.
authors.forename: Farimah
authors.initials: F
authors.lastname: Aminian
authors.forename: Maryam
authors.initials: M
authors.lastname: Esmaeilzadeh
authors.forename: Hassan
authors.initials: H
authors.lastname: Moladoust
authors.forename: Majid
authors.initials: M
authors.lastname: Maleki
authors.forename: Soraya
authors.initials: S
authors.lastname: Shahrzad
authors.forename: Zahra
authors.initials: Z
authors.lastname: Emkanjoo
authors.forename: Anita
authors.initials: A
authors.lastname: Sadeghpour
mesh_terms: D000293:Adolescent; D000328:Adult; D017115:Catheter Ablation; D015150:Echocardiography, Doppler / Q000379:methods; D005260:Female; D006352:Heart Ventricles / Q000503:physiopathology*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008297:Male; D008875:Middle Aged; D014102:Torsion Abnormality / Q000000981:diagnostic imaging* / Q000503:physiopathology; D014672:Vectorcardiography / Q000379:methods*; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000503:physiopathology; D014927:Wolff-Parkinson-White Syndrome / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery; D055815:Young Adult
keywords: Wolff-Parkinson-White syndrome; left ventricular rotation; radiofrequency catheter ablation; twist; velocity vector imaging