Evolution of Energy Sources in Surgical Ablation of Atrial Fibrillation: Current Technology and Future Directions.

Atrial fibrillation (AF) is the most common sustained arrhythmia worldwide and is associated with substantial morbidity, increased stroke risk, and a significant healthcare burden. While antiarrhythmic medications and catheter ablation remain central to rhythm control strategies, the efficacy of these therapies declines in persistent and long-standing persistent AF. Surgical ablation has consistently demonstrated superior long-term rhythm control, but this approach remains underutilized due to the associated perceived invasiveness and procedural complexity. Meanwhile, advances in energy sources have transformed the field, with bipolar radiofrequency (RF) and cryoablation established as the gold standard for lesion creation, supported by decades of durable outcomes. Nonetheless, both modalities possess limitations related to thermal injury and technical demands. Pulsed-field ablation (PFA), a non-thermal modality that induces irreversible electroporation (IRE), represents a promising new direction. Indeed, PFA preferentially ablates cardiomyocytes while sparing adjacent structures, enabling rapid, reproducible lesion formation with an improved safety profile. Preclinical studies have demonstrated the ability of this technology to create transmural lesions. Meanwhile, catheter-based studies have shown the associated efficacy and safety with this technology, and early feasibility trials suggest that surgical PFA clamps can replicate most of the Cox-Maze lesion set. Current surgical ablation lesion sets rely primarily on RF or cryoablation. However, emerging modalities such as PFA are poised to enable effective epicardial ablation on the beating heart, a challenge for thermal-based ablation technologies. With the advent of hybrid strategies that combine epicardial surgical ablation with catheter-based endocardial ablation, PFA may broaden the role of surgical ablation in advanced AF.