title: Comparison of monophasic and biphasic shocks for transthoracic cardioversion of atrial fibrillation.
abstract: OBJECTIVE
  To compare the efficacy of cardioversion in patients with atrial fibrillation between monophasic damped sine waveform and rectilinear biphasic waveform shocks at a high initial energy level and with a conventional paddle position.
  
  
  METHODS
  Prospective randomised study.
  
  
  METHODS
  227 patients admitted for cardioversion of atrial fibrillation to a tertiary referral centre.
  
  
  RESULTS
  70% of 109 patients treated with an initial 200 J monophasic shock were cardioverted to sinus rhythm, compared with 80% of 118 patients treated with an initial 120 J biphasic shock (NS). After the second shock (360 J monophasic or 200 J biphasic), 90% of the patients were in sinus rhythm in both groups. The mean cumulative energy used for successful cardioversion was 306 J for monophasic shocks and 159 J for biphasic shocks (p < 0.001).
  
  
  CONCLUSIONS
  A protocol using monophasic waveform shocks in a 200-360 J sequence has the same efficacy (90%) as a protocol using rectilinear biphasic waveform shocks in a 120-200 J sequence. This equal efficacy is achieved with a significantly lower mean delivered energy level using the rectilinear biphasic shock waveform. The potential advantage of lower energy delivery for cardioversion of atrial fibrillation needs further study.
authors.affiliation: Erasmus University Medical Centre, Thoraxcentre, Department of Clinical Electrophysiology, Rotterdam, Netherlands. m.f.scholten@erasmusmc.nl
authors.forename: M
authors.initials: M
authors.lastname: Scholten
authors.forename: T
authors.initials: T
authors.lastname: Szili-Torok
authors.forename: P
authors.initials: P
authors.lastname: Klootwijk
authors.forename: L
authors.initials: L
authors.lastname: Jordaens
mesh_terms: D001281:Atrial Fibrillation / Q000628:therapy*; D004554:Electric Countershock / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012008:Recurrence