Impedance compensated biphasic waveforms for transthoracic cardioversion of atrial fibrillation: a multi-centre comparison of antero-apical and antero-posterior pad positions

Eur Heart J. 2005 Jul;26(13):1298-302. doi: 10.1093/eurheartj/ehi196. Epub 2005 Apr 11.


Aims: To compare the success rate for transthoracic direct current cardioversion (DCC) of atrial fibrillation (AF) with antero-posterior (AP) and antero-apical (AA) electrode positions using an impedance compensated biphasic (ICB) waveform.

Methods and results: Three-hundred and seven patients [mean age 66 (SD+/-13), 195 male] with AF were recruited in three centres. Patients were randomized to an AA (n=150) or AP (n=144) pad position. Thirteen patients with implanted pacemakers were defaulted to the AP pad position. Cardioversion was performed using an ICB waveform with a 70, 100, 150, and 200 J energy selection protocol. If the fourth shock was unsuccessful, the pads were crossed over to the alternative position for a final 200 J shock. Shock 1 was successful in 54/150 (36%) AA and 45/144 (31%) AP patients, whereas success was achieved by shock 2 in 99/150 (66%) AA and 74/144 (51%) AP, by shock 3 in 123/150 (82%) AA and 109/144 (76%) AP, and by shock 4 in 143/150 (95%) AA and 127/144 (88%) AP and after cross-over in 144/150 (96%) AA and 135/144 (94%) AP. Overall success rate was higher than expected at 95%. Pad position was not associated significantly with success. There was a trend towards an improved outcome with the AA configuration (P=0.05).

Conclusion: The influence of pad position for DCC of AF may be less pertinent with ICB waveforms than with monophasic waveforms.

Publication types

  • Clinical Trial
  • Comparative Study
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Atrial Fibrillation / physiopathology
  • Atrial Fibrillation / therapy*
  • Cardiography, Impedance
  • Electric Countershock / instrumentation*
  • Electric Countershock / methods
  • Electrodes
  • Female
  • Humans
  • Male
  • Treatment Outcome