An interventional study of Synchronized Electrical Cardioversion With Different Energy Strategies and Conventional Step-Up Energy Cardioversion in Atrial Fibrillation (AF), sponsored by Second Affiliated Hospital, Zhejiang University, School of Medicine. Not yet recruiting. Open to participants aged 18 Years to 80 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-10-20.
Sponsored by Second Affiliated Hospital, Zhejiang University, School of Medicine · Not applicable, Interventional, and Treatment
This multicenter, randomized study will compare two electrical cardioversion energy strategies in adults with atrial fibrillation who are scheduled to undergo cardioversion during atrial fibrillation ablation or within 3 months after ablation. Eligible participants will be 18 to 80 years old, have a body mass index of at least 25 kg/m², and weigh more than 60 kg.
Participants will be randomly assigned to one of two groups. The first group will receive an initial shock of 150 joules, increased to 200 joules if needed. The second group will receive an initial shock based on body weight: 300 joules for participants weighing less than 90 kg and 360 joules for those weighing 90 kg or more. If the initial shock does not restore normal heart rhythm, further shocks will be delivered according to the study protocol.
The study will compare the proportion of participants in each group whose normal heart rhythm is restored shortly after cardioversion and whose rhythm remains stable. The study team will also record complications, changes in selected laboratory measures and quality of life, medication use, and treatment costs.
Electrical cardioversion is commonly used to restore normal heart rhythm in patients with atrial fibrillation. The energy level used during cardioversion may affect both the likelihood of restoring normal rhythm and the risk of complications. A lower initial energy may reduce exposure to high-energy shocks but may be less effective and require additional shocks. A higher initial energy selected according to body weight may improve cardioversion success, particularly in patients with higher body mass, but its effects on safety and other clinical outcomes require further evaluation.
This multicenter randomized study will compare a conventional step-up energy strategy with a body weight-based higher-energy strategy in patients with atrial fibrillation who are scheduled to undergo electrical cardioversion. The study will assess cardioversion success and maintenance of normal rhythm, as well as safety outcomes and other measures described in the study record. The results may help inform energy selection for cardioversion in this patient population.
3,957 studies on the registry are indexed under Atrial Fibrillation; 933 are open to participants now.
This study's planned enrollment of 400 is above the median of 145 across 2,437 interventional studies indexed under Atrial Fibrillation.
Browse Atrial Fibrillation studies →Second Affiliated Hospital, Zhejiang University, School of Medicine is the lead sponsor of 90 studies on the registry; 60 are open to participants now.
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Diagnosis of atrial fibrillation Age 18 to 80 years, inclusive.
Exclusion Criteria:
Severe cardiac disease, such as heart failure or valvular heart disease. Hemodynamically unstable atrial fibrillation. Severe hepatic or renal impairment. Unable to tolerate electrical cardioversion. Untreated hyperthyroidism. Pregnant. Previously enrolled in this study. Any other condition that, in the investigator's judgment, makes the participant unsuitable for the study.
Participants will undergo synchronized electrical cardioversion starting at 150 J. If the initial shock does not restore sinus rhythm, the energy will be increased to 200 J according to the study protocol.
Other: Conventional Step-Up Energy Cardioversion
Participants will undergo synchronized electrical cardioversion using an initial energy selected according to body weight: 300 J for participants weighing less than 90 kg and 360 J for participants weighing 90 kg or more. If the initial shock does not restore sinus rhythm, further shocks will be delivered according to the study protocol.
Other: Synchronized Electrical Cardioversion With Different Energy Strategies
Participants will undergo synchronized electrical cardioversion using a defibrillator monitor. The study compares two energy strategies: a conventional step-up strategy starting at 150 J and increasing to 200 J if needed, and a body weight-based strategy starting at 300 J for participants weighing less than 90 kg or 360 J for those weighing 90 kg or more. If the initial shock is unsuccessful, additional shocks will be delivered according to the study protocol.
Participants will receive synchronized electrical cardioversion starting at 150 J. If unsuccessful, the energy will be increased to 200 J.
First-Shock Cardioversion Success Within 1 Minute
Proportion of participants who return to sinus rhythm within 1 minute after the first synchronized electrical shock.
Time frame: Within 1 minute after the first shock
Overall Cardioversion Success Within 1 Minute
Proportion of participants who return to sinus rhythm within 1 minute after cardioversion, including any additional shocks given during the procedure.
Time frame: Within 1 minute after cardioversion
First-Shock Cardioversion Success Maintained for at Least 30 Minutes
Proportion of participants who return to sinus rhythm after the first shock and maintain sinus rhythm for at least 30 minutes.
Time frame: From the first shock through at least 30 minutes after restoration of sinus rhythm
Change in Cardiac Injury Biomarkers
Change from baseline in cardiac troponin and, if collected, creatine kinase and creatine kinase-MB. Baseline samples will be collected within 24 hours before cardioversion; follow-up samples will be collected 24 hours after cardioversion. Actual collection times will be recorded.
Time frame: Within 24 hours before and 24 hours after cardioversion
Change in Renal Function Measures
Change from baseline in serum creatinine and blood urea nitrogen, if measured as part of the study or routine clinical care.
Time frame: Within 24 hours before and 24 hours after cardioversion
Cardioversion-Related Adverse Events
Number and proportion of participants with arrhythmias, sinus node dysfunction, cardiac arrest, transient bradycardia, atrioventricular block, ventricular arrhythmia, thromboembolic events, or other serious adverse events. Events will be recorded during cardioversion and through 24 hours afterward; serious adverse events will be followed through 30 days.
Time frame: During cardioversion through 24 hours after cardioversion; serious adverse events through 30 days
Skin Reaction at Electrode Sites
Skin findings at the anterior and posterior electrode sites, categorized as no redness, mild redness, or skin burn.
Time frame: 2 hours after cardioversion
No study locations are listed for this record.
Documents are hosted by the registry — open the source record to download them.
Plan to share: No — Individual participant data collected in this study will not be shared with researchers outside the study team. Data sharing has not been approved under the current study protocol and data governance arrangements.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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Second Affiliated Hospital, Zhejiang University, School of Medicine