A comparison of rectilinear and truncated exponential biphasic waveforms in elective cardioversion of atrial fibrillation: a prospective randomized controlled trial
Resuscitation, 07/31/2012

Deakin CD et al. – Biphasic rectilinear (BR) and biphasic truncated exponential (BTE) waveforms show similar high efficacy in the elective cardioversion of atrial fibrillation.

• In a prospective randomised controlled study, sequential adult patients undergoing elective cardioversion for AF were recruited.
• Patients were randomised to receive synchronised defibrillation using either a BR or BTE waveform, both using a 50J, 100J, 150J, 200J, 200J selected energy escalating protocol.
• Failure to cardiovert after the fifth shock was classed as failed defibrillation.
• The power of this study was 80% with 5% significance level to detect a difference of 20% or greater between groups.
• Survival analysis was used to compare the total energy delivered to achieve successful cardioversion between groups.

• A total of 202 patients were recruited, of which data are complete for 199 (100 BR; 99 BTE).
• Median number of shocks to achieve cardioversion was 2 for the BR waveform and 3 for the BTE waveform (P=0.059).
• In the BR waveform group, 95/100 (95.0%) achieved sinus rhythm.
• In the BTE waveform group, 90/99 (90.9%) achieved sinus rhythm and this group required on average 117.1J more energy to achieve the outcome compared to the BR waveform group (P=0.838).