title: Right ventricular apical pacing impairs left ventricular twist as well as synchrony: acute effects of right ventricular apical pacing.
abstract: BACKGROUND
  This study was designed to compare the rotation of the left ventricular (LV) apex and base, LV synchrony between LV apical and basal rotation, and LV twist, changing from intrinsic atrioventricular conduction to right ventricular apical (RVA) pacing.
  
  
  METHODS
  Thirty consecutive patients with sick sinus syndrome who had undergone DDD pacemaker implantation were studied. Changing from intrinsic atrioventricular conduction to RVA pacing, the acute effect on echocardiographic parameters, including LV rotation and twist and LV apical-basal rotation delay, was assessed.
  
  
  RESULTS
  During RVA pacing, values of peak rotation in the LV apex and base and LV twist were significantly lower than during intrinsic atrioventricular conduction (P=.007, P=.003, and P<.0001, respectively). Apical-basal rotation delay during RVA pacing was significantly longer than during intrinsic atrioventricular conduction (P=.02).
  
  
  CONCLUSIONS
  RVA pacing decreases apical and basal LV rotation and induces LV apical-basal rotation delay, resulting in impairment of LV twist.
authors.affiliation: Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, and the Division of Cardiology, Osaka Rosai Hospital, Osaka, Japan. m.ken220@gmail.com
authors.forename: Ken
authors.initials: K
authors.lastname: Matsuoka
authors.forename: Masami
authors.initials: M
authors.lastname: Nishino
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Kato
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Egami
authors.forename: Ryu
authors.initials: R
authors.lastname: Shutta
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Yamaguchi
authors.forename: Kenjiro
authors.initials: K
authors.lastname: Tanaka
authors.forename: Jun
authors.initials: J
authors.lastname: Tanouchi
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Yamada
mesh_terms: D000368:Aged; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects*; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D016896:Treatment Outcome; D014463:Ultrasonography; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000209:etiology*; D018497:Ventricular Dysfunction, Right / Q000000981:diagnostic imaging* / Q000209:etiology*