Maximum-fixed energy shocks for cardioverting atrial fibrillation.

Area of Science:

• Cardiology
• Electrophysiology
• Medical Procedures

Background:

• Direct-current cardioversion is a common cardiac procedure.
• Optimal energy selection for cardioverting atrial fibrillation remains unclear.
• Low-escalating energy shocks are frequently used, but their efficacy compared to fixed high energy is debated.

Purpose of the Study:

• To compare the effectiveness and safety of maximum-fixed versus low-escalating energy shocks for cardioverting atrial fibrillation.
• To determine the optimal energy strategy for successful atrial fibrillation cardioversion.
• To evaluate safety endpoints including arrhythmias, myocardial injury, and pain.

Main Methods:

• A single-centre, single-blinded, randomized trial involving 276 elective atrial fibrillation patients.
• Patients were randomized to receive either maximum-fixed (360-360-360 J) or low-escalating (125-150-200 J) biphasic truncated exponential shocks.
• Primary endpoint was sinus rhythm at 1 minute post-cardioversion; safety endpoints included arrhythmias, myocardial injury, skin burns, and pain.

Main Results:

• Higher success rates for achieving sinus rhythm at 1 minute in the maximum-fixed group (88%) compared to the low-escalating group (66%).
• Significantly more patients achieved sinus rhythm after the first shock with maximum-fixed energy (75%) versus low-escalating energy (34%).
• No significant differences were observed in safety endpoints between the two energy groups.

Conclusions:

• Maximum-fixed energy shocks demonstrate superior effectiveness for cardioverting atrial fibrillation compared to low-escalating energy shocks.
• The study found no compromise in safety when using maximum-fixed energy shocks.
• These findings suggest that a maximum-fixed energy approach may be more advantageous for atrial fibrillation cardioversion.