title: Right ventricular septal pacing preserves global left ventricular longitudinal function in comparison with apical pacing: analysis of speckle tracking echocardiography.
abstract: BACKGROUND
  Right ventricular (RV) pacing alters left ventricular (LV) mechanical activation, resulting in adverse impacts on LV function. This study was aimed to investigate the acute effect of RV apical (RVA) and septal pacing (RVS) on LV dyssynchrony and function using speckle tracking echocardiography.
  
  
  RESULTS
  The 103 patients (749 years) with symptomatic bradyarrhythmia and preserved LV ejection fraction, and 50 age-matched control subjects were studied. All patients received a permanent pacemaker and were randomly assigned into 2 groups (RVA: n = 51, RVS: n = 52). After insertion, patients underwent an echocardiographic study during RV pacing. LV dyssynchrony and global strain parameters were analyzed using speckle tracking echocardiography. The QRS width and dyssynchrony indices by longitudinal and radial strain were significantly greater in RVA than in both the control and RVS. The LV longitudinal dyssynchrony index was significantly related to global longitudinal strain (GLS) among 103 patients receiving RV pacing (R² = 0.25, P < 0.0001). The GLS in RVA were the lowest among the 3 groups (GLS:
  
  
  METHODS
  -18.22.4%, RVA: -14.33.1%, P < 0.001 vs. control, RVS: -16.82.7%, P<0.01 vs. RVA).
  
  
  CONCLUSIONS
  RVA created heterogeneous LV contraction, which resulted in deteriorated LV longitudinal contraction. RVS could be a better pacing alternative in terms of less LV dyssynchrony and better longitudinal function compared to RVA.
authors: Division of Cardiology, Department of Integrated Medicine and Informatics, Ehime University Graduate School of Medicine, Japan.
authors: Katsuji
authors: K
authors: Inoue
authors: Hideki
authors: H
authors: Okayama
authors: Kazuhisa
authors: K
authors: Nishimura
authors: Makoto
authors: M
authors: Saito
authors: Toyofumi
authors: T
authors: Yoshii
authors: Go
authors: G
authors: Hiasa
authors: Takumi
authors: T
authors: Sumimoto
authors: Shinji
authors: S
authors: Inaba
authors: Jun
authors: J
authors: Suzuki
authors: Akiyoshi
authors: A
authors: Ogimoto
authors: Jun-Ichi
authors: J
authors: Funada
authors: Jitsuo
authors: J
authors: Higaki