July 27, 2026Journal of the American Heart Association0 citationsOpen Access
View Full PaperPragmatic Randomized Clinical Trial Comparing Rectilinear Biphasic Waveform and Biphasic Truncated Exponential Waveform Shocks for Cardioversion of Atrial Fibrillation
Key Result
A 200J rectilinear biphasic waveform shock achieved similar first-shock cardioversion to normal sinus rhythm as a 360J biphasic truncated exponential shock (82.6% vs 84.4%; P=0.565).
Key Points
- The aim was to compare the efficacy of rectilinear biphasic waveform and biphasic truncated exponential waveform shocks in converting atrial fibrillation to normal sinus rhythm.
- Open-label randomized controlled trial conducted across 3 hospitals.
- Adult patients with symptomatic atrial fibrillation were randomized 1:1 to receive 200J RBW or 360J BTE shocks.
- ECGs were obtained before and after shocks and analyzed by an electrophysiologist.
- Normal sinus rhythm was achieved in 223/270 (82.6%) with 200J RBW and 233/276 (84.4%) with 360J BTE (P=0.565).
- No significant differences in the rate of achieving normal sinus rhythm after multiple shocks between groups.
- Safety events showed no significant variance between RBW and BTE shock recipients.
Study Design
Type
RCT (n=546)
Blinding
Open-label
Randomization
1:1
Multicenter
Yes
Structured PICO
Does a 200J rectilinear biphasic waveform shock improve first shock cardioversion success compared to a 360J biphasic truncated exponential shock in adults with symptomatic atrial fibrillation?
P
Population
546 adult patients with symptomatic atrial fibrillation undergoing direct current cardioversion.
I
Intervention
Full-output 200J rectilinear biphasic waveform (RBW) synchronized shock
C
Comparator
Full-output 360J biphasic truncated exponential (BTE) synchronized shock
O
Outcome
Normal sinus rhythm on 12-lead ECG obtained ≥1 minute after first shock deliverysurrogate
A 200J rectilinear biphasic waveform shock is equally as effective and safe as a 360J biphasic truncated exponential shock for the direct current cardioversion of atrial fibrillation.
Main Result
Absolute Event Rate: 82.6% vs 84.4%
p-value: p=0.565
Abstract
Background No adequately powered prospective studies have compared the safety and efficacy of rectilinear biphasic waveform (RBW) shocks and biphasic truncated exponential (BTE) shocks for direct current cardioversion of atrial fibrillation. The study objective was to compare the efficacy of first shock direct current cardioversion from atrial fibrillation to normal sinus rhythm using a full‐output 200J RBW synchronized shock or a full‐output 360J BTE synchronized shock. Methods This investigator‐initiated, open‐label, unblinded, randomized controlled trial was performed at 3 hospitals in the Inova Health System between July 2023 and July 2024. Adult patients with symptomatic atrial fibrillation were randomized 1:1 to full‐output shock using a 200J RBW or 360J BTE shock waveform defibrillator. ECGs were performed before and 1 minute after each shock and adjudicated by a board‐certified electrophysiologist blinded to treatment assignment. Skin pads were positioned in an anterolateral placement in all patients. Successful direct current cardioversion was defined as normal sinus rhythm on 12‐lead ECG obtained ≥1 minute after shock delivery. Results A total of 546 unique patients were eligible for randomization, 270 patients were randomized to a 200J RBW shock and 276 patients to a 360J BTE shock. Normal sinus rhythm ≥1 minute after first shock delivery occurred in 223/270 (82.6%) patients randomized to 200J RBW shock and in 233/276 (84.4%) patients randomized to 360J BTE shock ( P =0.565). Overall, there were no significant differences in the frequency of attaining normal sinus rhythm after multiple direct current cardioversion shocks or safety events between patients randomized to 200J RBW or 360J BTE shocks. Conclusions We observed no difference in safety or efficacy between full‐output RBW or BTE shocks for atrial fibrillation cardioversion. Registration URL: https://clinicaltrials.gov ; Unique Identifier: NCT05992623.
Cite This Study
Nguyen et al. (Sat,) conducted a rct in Symptomatic atrial fibrillation (n=546). Rectilinear biphasic waveform (RBW) shock vs. Biphasic truncated exponential (BTE) shock (360J) was evaluated on Normal sinus rhythm on 12-lead ECG obtained ≥1 minute after first shock delivery (p=0.565). A 200J rectilinear biphasic waveform shock achieved similar first-shock cardioversion to normal sinus rhythm as a 360J biphasic truncated exponential shock (82.6% vs 84.4%; P=0.565).