Left atrial wall thickness correlates with pulmonary vein reconnection following atrial fibrillation ablation.

Background: Pulmonary vein (PV) isolation is the cornerstone of radiofrequency (RF) ablation for atrial fibrillation (AF) and PV reconnection is a common cause of recurrent AF. The relationship between PV ostial wall thickness (WT) and durable PV isolation is a matter of ongoing investigation. Additionally, the relationship between catheter impedance and WT is not well understood. We studied the relationship between PV ostial WT, ablation lesion metrics, and PV reconnection.

Methods: 16 patients were identified who underwent an initial and redo AF ablation procedure and had a cardiac CTA analyzed using ADAS-3D imaging software performed prior to the initial ablation. Ablation lesion metrics from the initial ablation procedure were collected from the electroanatomic mapping software. Reconnected and isolated PV were identified based on electroanatomic mapping data collected at the redo AF ablation procedure. Patients with reconnected PV exhibited thicker left atrial walls (1.4 mm vs 1.2 mm, P < 0.05) and reconnected veins exhibited thicker ostial walls (1.7 mm, vs 1.5 mm, P < 0.05). LA volume, number of ablation lesions, and ablation lesion time were not significantly different between reconnected and isolated PV. Impedance drop during ablation was greater in patients with reconnected PV compared to patients with isolated PV (- 9.0 Ω vs - 6.6 Ω, P < 0.05). There was no correlation between PV ostial WT and ablation lesion impedance drop.

Conclusion: PV reconnection was associated with thicker LA and PV ostial WT. Future studies will examine whether targeting thicker PV ostial tissue with more aggressive lesion metrics or different ablation technology can improve PV isolation and ablationoutcomes.