title: Effect of right ventricular lead location on response to cardiac resynchronization therapy in patients with end-stage heart failure.
abstract: OBJECTIVE
  It is currently recommended to implant the left ventricular (LV) pacing lead at the lateral wall. However, the optimal right ventricular (RV) pacing lead location for cardiac resynchronization therapy (CRT) remains controversial. We sought to investigate whether optimizing the site for placement of the RV lead could further improve the long-term response to CRT in patients with advanced heart failure.
  
  
  RESULTS
  Between October 2006 and December 2007, a total of 73 consecutive patients with standard indication for CRT were enrolled. The enrolled patients were divided into two groups based on the RV lead location. There were 50 patients in RV apex (RVA) group and 23 patients in RV high septum (RVHS). The primary study endpoint was a decrease in LV end-systolic volume (LVESV) by >15% at 6-month follow-up. The secondary endpoints were improvement in New York Heart Association (NYHA) class by >or=1 point and decrease in brain-type natriuretic peptide (BNP) levels by >50% after CRT. At 6-month follow-up, improvement in NYHA class by >or=1 point (RVA: 72% vs. RVHS: 74%, P = 0.76), decrease in LVESV by >or=15% (RVA: 65% vs. RVHS: 64%, P = 0.76), and decrease in BNP level by >50% (RVA: 70% vs. RVHS: 69%, P = 0.88) were observed in similar proportion of the two groups. When we separately assessed the significance of RV pacing site in three LV stimulation sites, there were no significant differences in terms of clinical improvement (62 vs. 64%, P = 0.74) and decrease in LVESV by >15% (63 vs. 62%, P = 0.78) between RVA and RVHS pacing when the LV stimulation site was lateral cardiac vein. In anterolateral vein pacing site, the RVA stimulation was associated with higher clinical (88 vs. 47%, P = 0.05), echocardiographic (75 vs. 32%, P = 0.02), and neurohormonal responses (80 vs. 50%, P = 0.04) compared with that in RVHS site. When LV was paced from posterolateral vein, RVHS pacing was superior to RVA in terms of the clinical improvement (85 vs. 35%, P = 0.01), echocardiographic response (72 vs. 30%, P = 0.01), and decrease in BNP levels (75 vs. 50%, P = 0.04).
  
  
  CONCLUSIONS
  The present study did not show any difference between RVA and RVHS pacing sites in terms of overall improvement in clinical outcome and LV reverse remodelling following CRT. However, effect of RV lead location on CRT response varies depending on LV stimulation site.
authors.affiliation: Department of Pacemaker and Electrophysiology, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, PO Box: 15745-1341, Mellat Park, Vali-E-Asr Avenue, Tehran 1996911151, Iran. majid.haghjoo@gmail.com
authors.forename: Majid
authors.initials: M
authors.lastname: Haghjoo
authors.forename: Hamid Reza
authors.initials: HR
authors.lastname: Bonakdar
authors.forename: Mohammad Vahid
authors.initials: MV
authors.lastname: Jorat
authors.forename: Amir Farjam
authors.initials: AF
authors.lastname: Fazelifar
authors.forename: Abolfath
authors.initials: A
authors.lastname: Alizadeh
authors.forename: Zahra
authors.initials: Z
authors.lastname: Ojaghi-Haghjghi
authors.forename: Maryam
authors.initials: M
authors.lastname: Esmaielzadeh
authors.forename: Mohammad Ali
authors.initials: MA
authors.lastname: Sadr-Ameli
mesh_terms: D002304:Cardiac Pacing, Artificial / Q000379:methods*; D004567:Electrodes, Implanted; D005260:Female; D006333:Heart Failure / Q000517:prevention & control*; D006352:Heart Ventricles / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D019919:Prosthesis Implantation / Q000379:methods*; D013727:Terminal Care