Anteroposterior vs Anterolateral Shock Vectors for Atrial Fibrillation Cardioversion: Design and Rationale of the...

Area of Science:

• Cardiology
• Electrophysiology
• Medical Devices

Background:

• Atrial fibrillation (AF) prevalence is rising, impacting patient survival and healthcare resources.
• Restoring sinus rhythm improves patient survival and quality of life.
• Current guidelines for electrical cardioversion lack conclusive evidence on optimal electrode positioning and manual pressure.

Purpose of the Study:

• To compare the efficacy of anterolateral (AL) versus anteroposterior (AP) electrode placement for first-shock success in AF cardioversion.
• To evaluate the impact of manual chest pressure on cardioversion success.
• To assess cumulative success rates and analyze subgroups based on sex, obesity, and left atrial size.

Main Methods:

• A randomized trial involving 1750 patients undergoing electrical cardioversion for AF.
• Patients are randomized to AL vs. AP electrode positions and to the addition of manual pressure vs. no pressure on a second shock.
• Biphasic maximal energy (≥ 200 J) is used for all shocks, with a third shock allowed at clinician discretion.

Main Results:

• The study demonstrated the feasibility of conducting a randomized trial on electrode placement and manual pressure in AF cardioversion.
• Enrollment is ongoing, with 390 patients completing the pilot phase.
• This trial is designed to be the first adequately powered study on this topic, enabling meaningful subgroup analyses.

Conclusions:

• The SHOCK-VECTOR trial is poised to provide crucial evidence on optimizing electrical cardioversion techniques for atrial fibrillation.
• Findings will inform clinical practice guidelines for AF management.
• The study's design allows for robust subgroup analyses to personalize AF treatment strategies.