Abstract

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 (DCC) of atrial fibrillation (AF).

Methods and Results This prospective multicentre randomised trial enrolled 380 patients (248 male, mean age 67 (SD 10) years) with AF. Patients were randomised to either an escalating energy protocol (Protocol A; 100J, 150J, 200J, 200J), or a non-escalating energy protocol (Protocol B; 200J, 200J, 200J). Cardioversion was performed using an impedance compensated biphasic waveform. First shock success was significantly higher for those randomised to 200 J than 100J (71% versus 48%; p < 0.01) and for patients with a Body Mass Index (BMI) > 25, (75% versus 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 is significantly higher particularly in patients with a BMI >25 when a non-escalating initial 200J energy was selected. The overall success, duration of procedure and amount of sedation administered however did not differ significantly between the two protocols.