# Ablation Parameters Predicting Pulmonary Vein Reconnection after Very High-Power Short-Duration Pulmonary Vein Isolation

## TL;DR

This study identifies ablation parameters that predict the durability of pulmonary vein isolation using high-power short-duration radiofrequency ablation for atrial fibrillation.

## Contribution

The study introduces specific ablation parameters that predict chronic pulmonary vein reconnection after very high-power short-duration ablation.

## Key findings

- Interlesion distance (ILD) cut-offs of 3.5 mm anteriorly and 4 mm posteriorly predict ablation gaps.
- Baseline generator impedance, mean current, and catheter–tissue contact loss are associated with ablation gaps.
- Smaller ILDs are needed for effective and durable vHPSD PVI compared to lower power ablation.

## Abstract

Background: Recurrences due to discontinuity in ablation lines are substantial after pulmonary vein isolation (PVI) with radiofrequency ablation for atrial fibrillation. Data are scarce regarding the durability predictors for very high-power short-duration (vHPSD, 90 W/4 s) ablation. Methods: A total of 20 patients were enrolled, who underwent 90 W PVI and a mandatory remapping procedure at 3 months. First-pass isolation (FPI) gaps, and acute pulmonary vein reconnection (PVR) sites were identified at the index procedure; and chronic PVR sites were identified at the repeated procedure. We analyzed parameters of ablation points (n = 1357), and evaluated their roles in predicting a composite endpoint of FPI gaps, acute and chronic PVR. Results: In total, 45 initial ablation points corresponding to gaps in the ablation lines were analyzed. Parameters associated with gaps were interlesion distance (ILD), baseline generator impedance, mean current, total charge, and loss of catheter–tissue contact. The optimal ILD cut-off for predicting gaps was 3.5 mm anteriorly, and 4 mm posteriorly. Conclusions: Biophysical characteristics dependent on generator impedance could affect the efficacy of vHPSD PVI. The use of smaller ILDs is required for effective and durable PVI with vHPSD compared to the consensus targets with lower power ablation, and lower ILDs for anterior applications seem necessary compared to posterior points.