General superiority of biphasic over uniphasic shocks in cardiac defibrillation

The comparative results of eight studies involving uniphasic and biphasic waveforms in 16383 transthoracic fibrillation-defibrillation episodes in 100-kg calves are critically summarized. A 1200-episode study of uniphasic and biphasic waveforms in epicardial and catheter defibrillation in dogs and two studies involving 733 defibrillation attempts using uniphasic and biphasic waveforms in the epicardial defibrillation of calves are presented. It is found that appropriate biphasic waveforms generally outperform uniphasic waveforms by (a) yielding a higher percent success, (b) requiring less energy to yield the peak possible value of success, and (c) furnishing quite successful results over a broader range of waveform parameters, thus making satisfactory performance less dependent on operator technique or patient-to-patient differences.<>