title: Relationship between left ventricular lead position using a simple radiographic classification scheme and long-term outcome with resynchronization therapy.
abstract: BACKGROUND
  Benefit from cardiac resynchronization therapy (CRT) is likely influenced by the location of the left ventricular (LV) lead.
  
  
  OBJECTIVE
  To evaluate the association of LV lead position with outcome after CRT.
  
  
  METHODS
  Two-hundred and fifty patients with LV dysfunction, New York Heart Association (NYHA) class III (68%) or IV (32%) symptoms, and QRS durations > or =120 ms were followed for a median of 30 months post-CRT. LV lead position was categorized as anterior (n = 20, 8%), lateral (n = 128, 51%), or posterior (n = 102; 41%) using postero-anterior and lateral postoperative chest radiographs.
  
  
  RESULTS
  Median age was 69 years and most (68%) had ischemic LV dysfunction. Clinical response, defined by a > or =1 NYHA class reduction, was lower in patients with an anterior (30%) versus lateral (76%) or posterior (73%) lead position (p = 0.001). An anterior versus nonanterior position was independently associated with a two to three-fold higher risk for nonresponse to CRT, cardiovascular death, death from worsening heart failure or cardiac transplantation, and death from any cause. Repositioning of the LV lead from an anterior to a nonanterior position in seven patients who had not clinically responded to CRT after > or =6 months resulted in clinical improvement in all cases.
  
  
  CONCLUSIONS
  An anterior versus nonanterior LV lead position is independently associated with an increased likelihood of nonresponse to CRT and a higher risk of serious outcomes. Repositioning of an anteriorly placed LV lead to a nonanterior position should be considered in CRT nonresponders.
authors.affiliation: Libin Cardiovascular Institute of Alberta, University of Calgary, Canada.
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Wilton
authors.forename: Mariko A
authors.initials: MA
authors.lastname: Shibata
authors.forename: Rachel
authors.initials: R
authors.lastname: Sondergaard
authors.forename: Karen
authors.initials: K
authors.lastname: Cowan
authors.forename: Lisa
authors.initials: L
authors.lastname: Semeniuk
authors.forename: Derek V
authors.initials: DV
authors.lastname: Exner
mesh_terms: D000368:Aged; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D018450:Disease Progression; D004567:Electrodes, Implanted; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011859:Radiography; D018709:Statistics, Nonparametric; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*