Optimizing pulmonary vein and posterior wall isolation to target adjacent sites of localized reentry during atrial fibrillation: acute results of a novel, ultrahigh density mapping algorithm

Pulmonary vein (PV) plus posterior wall (PW) isolation is often performed as an empirical strategy in non-paroxysmal atrial fibrillation (AF) patients. This approach is traditionally guided by anatomical landmarks and assumes that PVs and PW harbor triggers contributing to initiation, as well as drivers maintaining AF. An ultrahigh density mapping (UHD) tool has been recently developed, which automatically assesses ablation targets with consistent morphology and activations from intracardiac electrograms (EGMs).

To describe the distribution of left atrial (LA) regions of interest (ROIs) featuring EGMs denoting stable localized reentry and report the acute results of an individualized pulsed field ablation (PFA) strategy where isolation of PVs and PW is optimized to include adjacent ROIs detected by the algorithm.

We enrolled 36 non-paroxysmal AF patients undergoing first-time ablation at 3 European centers.

LA mapping was performed during AF by using a 64-pole catheter. The target number of EGMs was >25000. PFA was performed via a 5-spline catheter. After PV and PW isolation, ablation was extended to ROIs adjacent to the PVs or PW.

We included 25 (69.4%) persistent and 11 (30.6%) long-standing persistent AF patients (67.6+/-9.4 years, 63.9% males, median AF duration: 4.3 [interquartile range (IQR): 2.6-12] months). LA mapping time was 19.3+/-11.1 min (mean EGMs: 31872+/-19249). A median of 3 [3-4] AF sources were detected; 28 (77.8%) and 28 (77.8%) patients had ≥1 ROI harbored at the PV antra (median: 1.5 [1-2]) or PW (median: 1 [1-2]), respectively. Further PFA was delivered to 1.5 [1-2] ROIs adjacent to the PV/PW isolation area in 22 (61.1%) patients.

PFA led to AF termination in 26 (72.2%) patients; 58.3% was in sinus rhythm after ablation. AF termination occurred concomitantly to ablation of a ROI in 63.9% of patients.

Overall, 79+/-19 PFA applications were delivered; LA dwelling time (mapping plus ablation) was 68+/-30 min. None of the patients experienced any major periprocedural complications.

Individualized PV and PW isolation to target sites with stable localized rotational activations detected by the novel AF Mapping EGM-based tool effectively terminated AF in 72.2% of patients. Follow-up data to assess the impact of this ablation strategy in the long-term are warranted.

LA Map showing a Ockham point