title: Is right ventricular mid-septal pacing superior to apical pacing in patients with high degree atrio-ventricular block and moderately depressed left ventricular function?
abstract: OBJECTIVE
  We are aimed to investigate whether right ventricular mid-septal pacing (RVMSP) is superior to conventional right ventricular apical pacing (RVAP) in improving clinical functional capacity and left ventricular ejection fraction (LVEF) for patients with high-degree atrio-ventricular block and moderately depressed left ventricle (LV) function.
  
  
  METHODS
  Ninety-two patients with high-degree atrio-ventricular block and moderately reduced LVEF (ranging from 35% to 50%) were randomly allocated to RVMSP (n=45) and RVAP (n=47). New York Heart Association (NYHA) functional class, echocardiographic LVEF, and distance during a 6-min walk test (6MWT) were determined at 18 months after pacemaker implantation. Serum levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) were measured using an enzyme-linked immunosorbent assay (ELISA) kit.
  
  
  RESULTS
  Compared with baseline, NYHA functional class remained unchanged at 18 months, distance during 6MWT (485 m vs. 517 m) and LVEF (36.7% vs. 41.8%) were increased, but BNP levels were reduced (2352 pg/ml vs. 710 pg/ml) in the RVMSP group compared with those in the RVAP group, especially in patients with LVEF 35%-40% (for all comparisons, P<0.05). However, clinical function capacity and LV function measurements were not significantly changed in patients with RVAP, despite the pacing measurements being similar in both groups, such as R-wave amplitude and capture threshold.
  
  
  CONCLUSIONS
  RVMSP provides a better clinical utility, compared with RVAP, in patients with high-degree atrioventricular block and moderately depressed LV function whose LVEF levels ranged from 35% to 40%.
authors.affiliation: Department of Cardiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; Outpatient Department, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.
authors.forename: Kang
authors.initials: K
authors.lastname: Chen
authors.forename: Ye
authors.initials: Y
authors.lastname: Mao
authors.forename: Shao-hua
authors.initials: SH
authors.lastname: Liu
authors.forename: Qiong
authors.initials: Q
authors.lastname: Wu
authors.forename: Qing-zhi
authors.initials: QZ
authors.lastname: Luo
authors.forename: Wen-qi
authors.initials: WQ
authors.lastname: Pan
authors.forename: Qi
authors.initials: Q
authors.lastname: Jin
authors.forename: Ning
authors.initials: N
authors.lastname: Zhang
authors.forename: Tian-you
authors.initials: TY
authors.lastname: Ling
authors.forename: Ying
authors.initials: Y
authors.lastname: Chen
authors.forename: Gang
authors.initials: G
authors.lastname: Gu
authors.forename: Wei-feng
authors.initials: WF
authors.lastname: Shen
authors.forename: Li-qun
authors.initials: LQ
authors.lastname: Wu
mesh_terms: D000368:Aged; D054537:Atrioventricular Block / Q000150:complications / Q000175:diagnosis* / Q000628:therapy*; D015415:Biomarkers / Q000097:blood; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D005260:Female; D006352:Heart Ventricles; D006801:Humans; D008297:Male; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis* / Q000209:etiology / Q000517:prevention & control*
chemical_list: D015415:Biomarkers; D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain
keywords: Apical pacing; Impaired heart function; Mid-septal pacing