title: The efficacy of pad placement for electrical cardioversion of atrial fibrillation/flutter: a systematic review.
abstract: OBJECTIVE
  Electrical cardioversion is commonly used to treat patients with atrial fibrillation and atrial flutter to restore normal sinus rhythm. There has been considerable debate as to whether the electrode placement affects the efficacy of electrical cardioversion. The objective of this study was to examine the effectiveness of anteroposterior (A-P) versus anterolateral (A-L) electrode placement to restore normal sinus rhythm.
  
  
  METHODS
  A search of eight electronic databases, including Medline, EMBASE, CINAHL, and Cochrane was completed. Grey literature (hand-searching, Google, and SCOPUS) searching was also conducted. Studies were included if they were controlled clinical trials comparing the effectiveness of A-P versus A-L pad placement to restore normal sinus rhythm in adult patients with atrial fibrillation and flutter. Two independent reviewers judged study relevance, inclusion, and quality (e.g., risk of bias). Individual and pooled statistics were calculated as relative risks (RRs) with 95% confidence intervals (CIs) using a random-effects model, and heterogeneity (I(2) ) was reported.
  
  
  RESULTS
  From 788 citations, 13 studies were included; seven involved monophasic, five involved biphasic, and one analyzed both waveform devices. The included studies tended to report cumulative success rates to restoring normal sinus rhythm after one to five sequential shocks of increasing energy; the number of shocks and energy used differed among studies. The risk of bias of the studies was "unclear." After the first shock, pad placement was not associated with an increased likelihood of restoring normal sinus rhythm (RR = 0.88; 95% CI = 0.73 to 1.06); however, heterogeneity was high (I(2) = 63%). Subgroup comparisons revealed that the A-L position was more effective (RR = 0.77; 95% CI = 0.59 to 1.00) at restoring normal sinus rhythm when using biphasic shocks (comparison p = 0.04). Overall, the pooled results failed to identify a difference between A-P and A-L pad placement in restoring normal sinus rhythm at any time (RR = 1.00; 95% CI = 0.95 to 1.05); however, heterogeneity was high (I(2) = 61%). No significant subgroup differences were found. Side effects were reported in only three studies.
  
  
  CONCLUSIONS
  The published literature is restricted to persistent atrial fibrillation and atrial flutter, pad placement varied, and energy levels used were lower than currently recommended; however, the accumulated evidence suggests that electrical pad placement is not a critically important factor in successful cardioversion in atrial fibrillation and flutter (AF/AFL). A trial is urgently needed in recent-onset atrial fibrillation and atrial flutter patients using biphasic devices and high energy levels to resolve the debate.
authors.affiliation: Department of Emergency Medicine, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Scott
authors.initials: S
authors.lastname: Kirkland
authors.forename: Ian
authors.initials: I
authors.lastname: Stiell
authors.forename: Tariq
authors.initials: T
authors.lastname: AlShawabkeh
authors.forename: Sandy
authors.initials: S
authors.lastname: Campbell
authors.forename: Garth
authors.initials: G
authors.lastname: Dickinson
authors.forename: Brian H
authors.initials: BH
authors.lastname: Rowe
mesh_terms: D000328:Adult; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000188:drug therapy / Q000628:therapy*; D001282:Atrial Flutter / Q000188:drug therapy / Q000628:therapy*; D003131:Combined Modality Therapy; D004554:Electric Countershock / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D011292:Premedication
chemical_list: D000889:Anti-Arrhythmia Agents