Optimized Posterior Left Atrial Wall Ablation Strategy for PeAF

PVI + Posterior Wall Isolation (PWI) + Electrogram Ablation (EGM) After performing PVI, electrogram mapping of the posterior left atrial wall is conducted. Subsequently, PWI and EGM ablation are performed. In this group, multipolar mapping catheters are used for EGM mapping. Target EGMs include spatially discrete potentials (STPs), localized short cycle length potentials (SCLPs), and focal activities.

After performing PVI, the mapping catheter will be placed on the posterior wall to assess electrical activity and guide ablation. A bottom linear ablation (25-40W) will be performed, connecting the lowest points beneath the lower PVs. A top linear ablation (25-40W) will be conducted at the top of the left atrium, connecting the highest points above the upper PVs. If posterior wall isolation is not achieved after completing the bottom and top lines, mapping and localization of the earliest activation point within the box will be performed during pacing from the coronary sinus (CS). Posterior wall isolation will be completed by identifying and ablating local potentials at the entry and exit sites.

The distance between the ablation lines on the posterior wall after circumferential pulmonary vein isolation should be at least 2 centimeters to limit the portion of the posterior wall within the PVI ablation zone. PVI will be confirmed by verifying entrance and exit block at the PV orifices.