title: Left ventricular pacing with a new quadripolar transvenous lead for CRT: early results of a prospective comparison with conventional implant outcomes.
abstract: BACKGROUND
  Flexible left ventricular (LV) pacing configurations are a useful component of cardiac resynchronization therapy (CRT) systems for preventing high LV pacing thresholds and phrenic nerve stimulation (PNS). A quadripolar LV lead has recently been designed with the purpose of allowing more choices in lead placement location and programming capability.
  
  
  OBJECTIVE
  To verify the effectiveness of quadripolar LV leads compared to conventional bipolar LV leads implant outcomes.
  
  
  METHODS
  Forty-five consecutive patients underwent implantation with either the quadripolar (n = 22; quadripolar group) or a conventional bipolar LV lead (n = 23; bipolar group). The primary outcome of the study was LV lead failure, defined as the need for lead revision or reprogramming during the first 3 months after implantation. Additionally, operative and follow-up data were prospectively noted and checked for significance between groups.
  
  
  RESULTS
  The implantation success rate in both groups was 100%. Baseline characteristics, procedure duration, and fluoroscopy time did not differ significantly between groups. Two lead dislodgments (requiring reoperation) and 4 clinical PNS were reported in the bipolar group; reprogramming of the device was sufficient to prevent PNS in 3 patients, the fourth is pending solution. One PNS successfully managed noninvasively occurred in the quadripolar group. By Kaplan-Meier analysis, event-free survival for the combined primary outcome was significantly lower in patients with quadripolar leads (P = .037).
  
  
  CONCLUSIONS
  This prospective, controlled study provides strong evidence that CRT with the quadripolar LV lead results in low rates of dislocations and phrenic nerve stimulation.
authors.affiliation: University of Rome Tor Vergata, Department of Internal Medicine, Division of Cardiology, Rome, Italy. forleo@me.com
authors.forename: Giovanni B
authors.initials: GB
authors.lastname: Forleo
authors.forename: Domenico G
authors.initials: DG
authors.lastname: Della Rocca
authors.forename: Lida P
authors.initials: LP
authors.lastname: Papavasileiou
authors.forename: Arianna Di
authors.initials: AD
authors.lastname: Molfetta
authors.forename: Luca
authors.initials: L
authors.lastname: Santini
authors.forename: Francesco
authors.initials: F
authors.lastname: Romeo
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D058406:Cardiac Resynchronization Therapy; D004558:Electric Stimulation; D004567:Electrodes, Implanted; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010791:Phrenic Nerve; D011446:Prospective Studies; D016896:Treatment Outcome; D020257:Ventricular Remodeling