CellFX® Nanosecond Pulsed Field Ablation (nsPFA)™ Cardiac Surgery Clamp System to Treat Atrial Fibrillation

This study is testing a new surgical device that uses very short, powerful electrical pulses (nanosecond pulsed field ablation) to treat atrial fibrillation (AF) — an irregular heartbeat — during heart surgery. The device delivers energy to the heart tissue to destroy the abnormal electrical pathways that cause AF, without the heat damage of older methods. **You may be eligible if...** - You are between 18 and 85 years old - You have documented atrial fibrillation (either intermittent/paroxysmal or persistent/long-standing) - You are scheduled for non-emergency heart surgery for another reason (such as valve repair or bypass) - You are willing to undergo AF treatment as part of the surgery and complete follow-up visits **You may NOT be eligible if...** - You have had a prior surgical or catheter-based ablation for AF - You have had a recent stroke or blood clot within the past 3 months - You have severe heart failure or other conditions making additional ablation too risky - You are pregnant Talk to your doctor to see if this trial is right for you.