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Heart rhythm disorders and pacemakers
Biphasic energy selection for transthoracic cardioversion of atrial fibrillation. The BEST AF Trial
  1. B M Glover1,2,
  2. S J Walsh1,
  3. C J McCann1,2,
  4. M J Moore1,2,
  5. G Manoharan1,2,
  6. G W N Dalzell1,
  7. A McAllister3,
  8. B McClements3,
  9. D J McEneaney4,
  10. T G Trouton5,
  11. T P Mathew6,
  12. A A J Adgey1,2
  1. 1
    Regional Medical Cardiology Centre, Royal Victoria Hospital, Belfast, Northern Ireland, UK
  2. 2
    Queens University of Belfast, Belfast, Northern Ireland, UK
  3. 3
    Department of Cardiology, Mater Hospital, Belfast, Northern Ireland, UK
  4. 4
    Craigavon Cardiac Centre, Craigavon Area Hospital, Craigavon, Northern Ireland, UK
  5. 5
    Department of Cardiology, Antrim Area Hospital, Antrim, Northern Ireland, UK
  6. 6
    Department of Cardiology, Nottingham City Hospital, Hucknall Road, Nottingham, UK
  1. Professor A A J Adgey, Regional Medical Cardiology Centre, Royal Victoria Hospital, Grosvenor Road, Belfast BT12 6BA, Northern Ireland, UK; jennifer.adgey{at}


Aims: To compare the efficacy and safety of an escalating energy protocol with a non-escalating energy protocol using an impedance compensated biphasic defibrillator for direct current cardioversion of atrial fibrillation (AF).

Methods and results: This prospective multicentre randomised trial enrolled 380 patients (248 male, mean (SD) age 67 (10) years) with AF. Patients were randomised to either an escalating energy protocol (protocol A: 100 J, 150 J, 200 J, 200 J), or a non-escalating energy protocol (protocol B: 200 J, 200 J, 200 J). Cardioversion was performed using an impedance compensated biphasic waveform. First-shock success was significantly higher for those randomised to 200 J than 100 J (71% vs 48%; p<0.01) and for patients with a body mass index (BMI) >25 kg/m2 (75% vs 44%; p = 0.01). In patients with a normal BMI there was no significant difference in first-shock success. There was also no significant difference between subsequent shocks or overall success. The use of a non-escalating protocol (protocol B) resulted in fewer shocks but with a higher cumulative energy. There was no difference in duration of procedure, amount of sedation administered or post-shock erythema between the groups.

Conclusion: First-shock success was significantly higher, particularly in patients with a BMI >25 kg/m2, when a non-escalating initial 200 J energy was selected. The overall success, duration of procedure and amount of sedation administered, however, did not differ significantly between the two protocols.

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  • Competing interests: None.

  • Funding: BMG is a recipient of a grant from Northern Ireland Chest Heart and Stroke Association.

  • Ethics approval: Approval was obtained from the Queen’s University of Belfast Research Ethics Committee.

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