Biphasic versus monophasic shock waveform for conversion of atrial fibrillation: The Results of an International Randomized, Double-Blind Multicenter Trial

• Published in: Journal of the American College of Cardiology 2002-06, Vol.39 (12), p.1956-1963
• Main Authors: PAGE, Richard L, KERBER, Richard E, LAZZARA, Ralph, LEE, Kerry, CARLSON, Mark, HALPERIN, Blair, BARDY, Gust H, RUSSELL, T. James K, TROUTON, Tom, WAKTARE, Johan, GALLIK, Donna, OLGIN, Jeff E, RICARD, Philippe, DALZELL, Gavin W, REDDY, Ramakota
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aged, 80 and over; Atrial Fibrillation - therapy; Biological and medical sciences; Cardiac arrhythmia; Cardiology; Confidence intervals; Diseases of the cardiovascular system; Double-Blind Method; Electric Countershock - methods; Electrodes; Female; Humans; Male; Medical sciences; Middle Aged; Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects); Success; Treatment Outcome
• ISSN: 0735-1097; 1558-3597
• DOI: 10.1016/S0735-1097(02)01898-3

This study compared a biphasic waveform with a conventional monophasic waveform for cardioversion of atrial fibrillation (AF). Biphasic shock waveforms have been demonstrated to be superior to monophasic shocks for termination of ventricular fibrillation, but data regarding biphasic shocks for conversion of AF are still emerging. In an international, multicenter, randomized, double-blind clinical trial, we compared the effectiveness of damped sine wave monophasic versus impedance-compensated truncated exponential biphasic shocks for the cardioversion of AF. Patients received up to five shocks, as necessary for conversion: 100 J, 150 J, 200 J, a fourth shock at maximum output for the initial waveform (200 J biphasic, 360 J monophasic) and a final cross-over shock at maximum output of the alternate waveform. Analysis included 107 monophasic and 96 biphasic patients. The success rate was higher for biphasic than for monophasic shocks at each of the three shared energy levels (100 J: 60% vs. 22%, p < 0.0001; 150 J: 77% vs. 44%, p < 0.0001; 200 J: 90% vs. 53%, p < 0.0001). Through four shocks, at a maximum of 200 J, biphasic performance was similar to monophasic performance at 360 J (91% vs. 85%, p = 0.29). Biphasic patients required fewer shocks (1.7 +/- 1.0 vs. 2.8 +/- 1.2, p < 0.0001) and lower total energy delivered (217 +/- 176 J vs. 548 +/- 331 J, p < 0.0001). The biphasic shock waveform was also associated with a lower frequency of dermal injury (17% vs. 41%, p < 0.0001). For the cardioversion of AF, a biphasic shock waveform has greater efficacy, requires fewer shocks and lower delivered energy, and results in less dermal injury than a monophasic shock waveform.