Biphasic waveform shocks were effective and efficient for cardioversion of atrial fibrillation.

I n t e r v e n t i o n Patients were allocated to impedance-compensated truncated exponential biphasic shocks (n = 96) or damped sine wave monophasic shocks (n = 107). Patients received up to 5 shocks: 100 joules (J), 150 J, 200 J, a fourth shock at maximum output for the initial waveform (200 J biphasic, 360 J monophasic), and a final crossover at maximum output of the alternate waveform. M a i n o u t c o m e m e a s u r e s Successful conversion to another rhythm, number of shocks and amount of energy delivered to patients, and dermal injury.