External cardioversion using biphasic shocks required significantly lower cumulative energy than monophasic shocks (P=0.001), with 95% overall success and no device dysfunction in either group.
RCT (n=44)
AIMS: External cardioversion (ECV) of atrial fibrillation (AF) may damage implanted pacemaker and cardioverter-defibrillator (ICD) systems. This prospective study evaluated the safety and efficacy of ECV comparing mono- to biphasic shock waveforms in patients with implanted rhythm devices. METHODS AND RESULTS: Patients with pacemaker or ICD systems and an indication for ECV were randomized to receive mono- or biphasic shocks. Systems were tested immediately before and after ECV, 1 h and 1 week later with respect to device and lead integrity. Forty-four patients (71 +/- 10 years, 31 male; 29 pacemakers, 12 ICDs, three cardiac resynchronization systems) underwent ECV with antero-posterior paddle orientation (monophasic in 21 and biphasic in 23 patients). Pacing impedances were reduced immediately after ECV (atrial 402-392 ohm, P < 0.001; ventricular 517-496 ohm, P = 0.001) and returned to baseline values within 1 week. Ventricular sensing was reduced immediately after ECV (12.4-11.6 mV, P = 0.004). There was no device or lead dysfunction in any patient. ECV was successful in 42/44 patients (95%), cumulative energy was significantly lower for biphasic compared with monophasic shocks (P = 0.001). CONCLUSION: ECV for AF seems to be safe and effective in patients with implanted rhythm devices.
Manegold et al. (Tue,) conducted a rct in Atrial fibrillation in patients with implanted rhythm devices (n=44). Biphasic shock external cardioversion vs. Monophasic shock external cardioversion was evaluated on Safety (device and lead integrity) and efficacy (successful cardioversion). External cardioversion using biphasic shocks required significantly lower cumulative energy than monophasic shocks (P=0.001), with 95% overall success and no device dysfunction in either group.