Trial results comparing two types of defibrillator shocks for cardioversion in Atrial Fibrillation were posted on 2025-09-22, indicating that 246 participants receiving a 200J Synchronized Rectilinear Biphasic Waveform (RBW) shock and 248 participants receiving a 360J Synchronized Biphasic Truncated Exponential Waveform (BTE) shock achieved normal sinus rhythm after one or two shocks.
Background
Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, increasing the risk of stroke and heart failure. Electrical cardioversion restores normal sinus rhythm using a controlled electrical shock. Optimizing defibrillator waveform and energy levels is crucial for successful cardioversion.
Trial design
This completed, single-center, open-label randomized controlled trial enrolled 546 participants with Atrial Fibrillation. The primary objective was to compare the efficacy of a single 200J RBW shock (Zoll Series R Defibrillator) against a single 360J BTE shock (Lifepak 15 Defibrillator) in achieving normal sinus rhythm. The trial was designated as Phase NA.
Key results
The trial evaluated the number of participants achieving normal sinus rhythm (NSR) after electrical cardioversion:
- After the first DCCV shock, 223 participants in the 200J RBW group achieved NSR, compared to 233 participants in the 360J BTE group. A Chi-squared analysis yielded a p-value of 0.565.
- After the first or second DCCV shock, 246 participants in the 200J RBW group achieved NSR, compared to 248 participants in the 360J BTE group. A Chi-squared analysis yielded a p-value of 0.617.
- For participants who crossed over, 6 achieved NSR after a 200J RBW shock, and 12 achieved NSR after a 360J BTE shock. A Chi-squared analysis for the mean difference in final values for crossover cases yielded a p-value of 0.05 with a mean difference of 0.04.
What this means
The results suggest both 200J RBW and 360J BTE shocks demonstrated similar efficacy in restoring normal sinus rhythm in atrial fibrillation patients. High p-values (0.565 and 0.617) for primary comparisons indicate no statistically significant difference between the two shock types for achieving NSR. This implies clinicians may have flexibility in choosing between these defibrillator settings or devices based on factors like availability or patient characteristics, without compromising cardioversion success rates for main outcomes.
Source
The information regarding these trial results was obtained from ClinicalTrials.gov. The results for the study NCT05992623, titled "Clinical Trial Comparing Devices Used for Cardioversion of Atrial Fibrillation", were posted on 2025-09-22 on clinicaltrials.gov.