title: Left Ventricular Lead Placement Targeted at the Latest Activated Site Guided by Electrophysiological Mapping in Coronary Sinus Branches Improves Response to Cardiac Resynchronization Therapy.
abstract: BACKGROUND
  Electrophysiological mapping (EPM) in coronary sinus (CS) branches is feasible for guiding LV lead placement to the optimal, latest activated site at cardiac resynchronization therapy (CRT) procedures. However, whether this procedure optimizes the response to CRT has not been demonstrated. This study was to evaluate effects of targeting LV lead at the latest activated site guided by EPM during CRT.
  
  
  METHODS
  Seventy-six consecutive patients with advanced heart failure who were referred for CRT were divided into mapping (MG) and control groups (CG). In MG, the LV lead, also used as a mapping bipolar electrode, was placed at the latest activated site determined by EPM in CS branches. In CG, conventional CRT procedure was performed. Patients were followed for 6 months after CRT.
  
  
  RESULTS
  Baseline characteristics were comparable between the 2 groups. In MG (n = 29), EPM was successfully performed in 85 of 91 CS branches during CRT. A LV lead was successfully placed at the latest activated site guided by EPM in 27 (93.1%) patients. Compared with CG (n = 47), MG had a significantly higher rate (86.2% vs. 63.8%, P = 0.039) of response (>15% reduction in LV end-systolic volume) to CRT, a higher percentage of patients with clinical improvement of ≥2 NYHA functional classes (72.4% vs. 44.7%, P = 0.032), and a shorter QRS duration (P = 0.004).
  
  
  CONCLUSIONS
  LV lead placed at the latest activated site guided by EPM resulted in a significantly greater CRT response, and a shorter QRS duration.
authors.affiliation: Department of Cardiology, General Hospital of Shenyang Military Region, Shenyang, China.
authors.forename: Yanchun
authors.initials: Y
authors.lastname: Liang
authors.affiliation: Department of Cardiology, General Hospital of Shenyang Military Region, Shenyang, China.
authors.forename: Haibo
authors.initials: H
authors.lastname: Yu
authors.affiliation: Department of Cardiology, General Hospital of Shenyang Military Region, Shenyang, China.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Zhou
authors.affiliation: Department of Cardiology, General Hospital of Shenyang Military Region, Shenyang, China.
authors.forename: Guoqing
authors.initials: G
authors.lastname: Xu
authors.affiliation: Department of Cardiology, General Hospital of Shenyang Military Region, Shenyang, China.
authors.forename: Y I
authors.initials: YI
authors.lastname: Sun
authors.affiliation: Department of Cardiology, General Hospital of Shenyang Military Region, Shenyang, China.
authors.forename: Rong
authors.initials: R
authors.lastname: Liu
authors.affiliation: Department of Cardiology, General Hospital of Shenyang Military Region, Shenyang, China.
authors.forename: Zulu
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Department of Cardiology, General Hospital of Shenyang Military Region, Shenyang, China.
authors.forename: Yaling
authors.initials: Y
authors.lastname: Han
mesh_terms: D000368:Aged; D058406:Cardiac Resynchronization Therapy / Q000379:methods*; D058409:Cardiac Resynchronization Therapy Devices; D054326:Coronary Sinus / Q000502:physiology*; D004562:Electrocardiography; D004567:Electrodes, Implanted; D055724:Electrophysiological Phenomena; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000628:therapy*; D006352:Heart Ventricles; D006801:Humans; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome
keywords: LV lead position; LV remodeling; cardiac resynchronization therapy; electrophysiological mapping; heart failure