title: Left ventricular torsion in paced patients.
abstract: BACKGROUND
  In healthy people the left ventricle presents a counter-clockwise apical rotation and a clockwise basal rotation ending in late systole. In early systole (during isovolumic contraction) there is a fast and inverse rotation (counter-clockwise at the base and clockwise at the apex). This opposite rotation between apex and base produces the systolic torsion of the left ventricle. The effect of permanent conventional pacing on this torsion is little known.
  
  
  OBJECTIVE
  The aim of this study was to assess, by speckle tracking echocardiography, left ventricular rotation and torsion in patients conventionally paced at the apex of the right ventricle.
  
  
  METHODS
  Left ventricular apical and basal rotation and the consequent torsion were evaluated by means of speckle tracking echocardiography, in 13 paced patients, without ischemic or valvular disease, and in 17 healthy participants. Left ventricular dyssynchrony was evaluated by means of temporal uniformity of strain.
  
  
  RESULTS
  In the paced group there was a significant reduction in early-systolic clockwise torsion (-0.4 degrees +/- 1.2 vs. -1.5 degrees +/- 1.6; P = 0.04), and in late-systolic counter-clockwise torsion (15.1 degrees +/- 4.3 vs. 19.1 degrees +/- 5.5; P = 0.03). Circumferential temporal uniformity of strain averaged significantly lower in paced patients.
  
  
  CONCLUSIONS
  Conventional pacing from the apex of the right ventricle alters both the torsional mechanic and the synchrony of the left ventricle.
authors.affiliation: Divisione Clinicizzata di Cardiologia, Azienda Ospedaliera Universitaria 'Maggiore della Carità', Novara, Italy. devecchipa@tin.it
authors.forename: Paolo
authors.initials: P
authors.lastname: Devecchi
authors.forename: Virginia
authors.initials: V
authors.lastname: Bolzani
authors.forename: Gianni
authors.initials: G
authors.lastname: Sarasso
authors.forename: Cristina
authors.initials: C
authors.lastname: Piccinino
authors.forename: Giuliano
authors.initials: G
authors.lastname: Marti
authors.forename: Eraldo
authors.initials: E
authors.lastname: Occhetta
authors.forename: Miriam
authors.initials: M
authors.lastname: Bortnik
authors.forename: Gabriella
authors.initials: G
authors.lastname: Francalacci
authors.forename: Andrea
authors.initials: A
authors.lastname: Magnani
authors.forename: Paolo
authors.initials: P
authors.lastname: Marino
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects*; D016022:Case-Control Studies; D004452:Echocardiography; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D015203:Reproducibility of Results; D012399:Rotation; D054159:Torsion, Mechanical; D016277:Ventricular Function, Left