No difference in cardioversion success between RBW and BTE waveforms for atrial fibrillationTrial Shows No Difference Between Two Shock Waveforms for Atrial Fibrillation

Journal of the American Heart Association Published August 9, 2026 Study authors: Nguyen Andrew H, Emaminia Abbas, Sandesara Chirag, Ilkhanoff Leonard, Gaeta Stephen A, Lee Jeff Jae,… PubMed ↗ NCT05992623 ↗ DOI ↗ Editorial oversight: Dr. Amelia Tan, PhD · Internal Medicine & Chronic Disease

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Key Takeaway

Note that no significant difference exists between RBW and BTE waveforms for atrial fibrillation cardioversion success.

This randomized trial evaluated the efficacy and safety of two different biphasic waveforms for direct current cardioversion in 546 adult patients with symptomatic atrial fibrillation across three hospitals. Patients were randomized to receive either a full-output 200J rectilinear biphasic waveform (RBW) or a full-output 360J biphasic truncated exponential (BTE) waveform.

The primary outcome was successful direct current cardioversion, defined as normal sinus rhythm on a 12-lead ECG at least 1 minute after the shock. The study reported success rates of 223/270 (82.6%) for the RBW group and 233/276 (84.4%) for the BTE group, with no significant difference observed between the two waveforms.

Secondary outcomes included the frequency of attaining normal sinus rhythm after multiple shocks and safety events; both measures showed no significant differences between groups. Safety data indicated that there were no significant differences in safety events between RBW and BTE cohorts.

The study was an investigator-initiated, open-label, and unblinded trial. These limitations may affect the interpretation of results. Clinically, the findings suggest that neither RBW nor BTE waveforms provide a superior advantage in efficacy or safety for atrial fibrillation cardioversion.

How this fits prior evidence

How this fits prior evidence: This study addresses the management of atrial fibrillation by evaluating waveform types during cardioversion. While previous coverage noted that DOAC plus calcium-channel blocker co-use raises major bleeding risk 21% in atrial fibrillation, and perioperative dexmedetomidine reduces postoperative atrial fibrillation and delirium risk in adult cardiac surgery patients, this trial specifically focuses on the technical parameters of electrical cardioversion. It confirms that both RBW and BTE waveforms are equally effective for achieving sinus rhythm.

Researchers conducted a randomized controlled trial to compare two types of electrical shocks used to treat patients with symptomatic atrial fibrillation. The study involved 546 adult patients across three hospitals. They compared a 200J rectilinear biphasic waveform (RBW) against a 360J biphasic truncated exponential (BTE) waveform.

The results showed that both types of shocks were effective at achieving normal sinus rhythm. Specifically, the success rate was 82.6% for the RBW group and 84.4% for the BTE group. There were no significant differences found between the two methods regarding how often patients achieved a normal heart rhythm after multiple shocks.

Safety data also showed no significant differences in adverse events between the two groups. While this trial was open-label and unblinded, it suggests that both waveforms are comparable for cardioversion. Patients and doctors can view these two options as having similar efficacy and safety profiles for treating atrial fibrillation.

What this means for you:

Two different electrical shock types showed similar success rates and safety levels for treating atrial fibrillation.

Common questions

Are both types of electrical shocks safe for atrial fibrillation?

The study found no significant differences in safety events between the two types of shock waveforms. Both the 200J RBW and the 360J BTE methods were reported as having similar safety profiles during the trial. You should talk to your doctor about which specific method is best for your personal health needs.

How effective are these different shock waveforms?

Both types of shocks were effective at achieving normal sinus rhythm. The study reported a success rate of 82.6% for the RBW group and 84.4% for the BTE group. There was no significant difference in how often patients reached a normal heart rhythm after multiple shocks.

What is the main difference between RBW and BTE shocks?

The study compared two different waveforms: a 200J rectilinear biphasic waveform (RBW) and a 360J biphasic truncated exponential (BTE). While they use different energy levels and shapes, the trial showed no significant difference in their success rates or safety for treating atrial fibrillation.

Study Details

Study typeRct

Sample sizen = 270

EvidenceLevel 2

PublishedAug 2026

PMID42500901

TrialNCT05992623

View Original 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 (=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.

No difference in cardioversion success between RBW and BTE waveforms for atrial fibrillationTrial Shows No Difference Between Two Shock Waveforms for Atrial Fibrillation

How this fits prior evidence

Common questions

Study Details

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No difference in cardioversion success between RBW and BTE waveforms for atrial fibrillationTrial Shows No Difference Between Two Shock Waveforms for Atrial Fibrillation

How this fits prior evidence

Common questions

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