title: Right Bundle Branch Block-Like Pattern During Ventricular Pacing: A Surface Electrocardiographic Mapping Technique to Locate the Ventricular Lead.
abstract: BACKGROUND
  In patients with paced rhythm, a right bundle branch block (RBBB)-like pattern may suggest inadvertent left ventricular (LV) lead placement. However, in most cases, the lead is indeed in the right ventricle as intended.
  
  
  METHODS
  We performed a retrospective analysis of postimplantation electrocardiograms (ECGs) for the period 2000-2013 to determine the prevalence of a RBBB-like pattern. A 12-lead ECG was recorded in the standard position and with displacement of leads V1-V2 to the fifth and sixth intercostal spaces (ICSs), assessing the ability of this manoeuvre to unmask a concealed LBBB-like pattern. Patients with true LV pacing, both endocardial and epicardial, were used as controls (n = 10).
  
  
  RESULTS
  A total of 943 patients were analyzed. The prevalence of RBBB-like pattern was 8.1% (n = 77), and 26 patients were included in the study. Displacement of leads V1-V2 to the fifth ICS resulted in transition to a LBBB-like pattern with a QS wave in V1 in 14 of 26 patients (sensitivity, 53%; specificity, 100%), whereas displacement to the sixth ICS resulted in a QS pattern in all patients (sensitivity and specificity, 100%). In all patients in the control group, the ECG depicted a RBBB configuration with leads V1-V2 in the standard position, as well as at the fifth and sixth ICSs.
  
  
  CONCLUSIONS
  In patients with paced rhythm and a RBBB-like pattern on the 12-lead ECG, displacement of leads V1-V2 to the sixth ICS accurately identifies the presence of true right ventricular pacing.
authors.affiliation: Division of Cardiology, Kingston General Hospital, Queen's University, Kingston, Ontario, Canada.
authors.forename: Mohammed
authors.initials: M
authors.lastname: Almehairi
authors.affiliation: Division of Cardiology, Kingston General Hospital, Queen's University, Kingston, Ontario, Canada.
authors.forename: Andres
authors.initials: A
authors.lastname: Enriquez
authors.affiliation: Division of Cardiology, Kingston General Hospital, Queen's University, Kingston, Ontario, Canada.
authors.forename: Damian
authors.initials: D
authors.lastname: Redfearn
authors.affiliation: Division of Cardiology, Kingston General Hospital, Queen's University, Kingston, Ontario, Canada.
authors.forename: Kevin
authors.initials: K
authors.lastname: Michael
authors.affiliation: Division of Cardiology, Kingston General Hospital, Queen's University, Kingston, Ontario, Canada.
authors.forename: Hoshiar
authors.initials: H
authors.lastname: Abdollah
authors.affiliation: Division of Cardiac Electrophysiology, Prince Sultan Cardiac Center, Military Hospital, Riyadh, Saudi Arabia.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Alfagih
authors.affiliation: Department of Radiology, Kingston General Hospital, Queen's University, Kingston, Ontario, Canada.
authors.forename: Robert
authors.initials: R
authors.lastname: Nolan
authors.affiliation: Division of Cardiology, Kingston General Hospital, Queen's University, Kingston, Ontario, Canada.
authors.forename: Adrian
authors.initials: A
authors.lastname: Baranchuk
authors.affiliation: Division of Cardiology, Kingston General Hospital, Queen's University, Kingston, Ontario, Canada. Electronic address: simpsonc@kgh.kari.net.
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Simpson
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D018780:Body Surface Potential Mapping / Q000379:methods*; D002037:Bundle-Branch Block / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects*; D004452:Echocardiography; D004868:Equipment Failure; D005260:Female; D005500:Follow-Up Studies; D006352:Heart Ventricles / Q000503:physiopathology*; D006801:Humans; D015994:Incidence; D008297:Male; D009864:Ontario / Q000453:epidemiology; D011379:Prognosis; D012189:Retrospective Studies