Grid annotation vs. ablation tags in predicting lesion area coverage for pulmonary vein isolation using a variable-loop circular catheter
G Vetta, C Audiat, D G Della Rocca, L Marcon, L Pannone, J Sieira, E Stroker, A Del Monte, C De Asmundis, G B Chierchia, A AlmoradAbstract
Background
The Variable-Loop Circular Catheter (VLCC) is a bidirectional multi-electrode catheter capable of electroanatomical mapping and pulsed field energy delivery for the treatment of atrial fibrillation (AF).
Objective
to compare Grid projected annotation (GRID) versus projected Ablation tags (ABLt) in predicting lesion area coverage for Pulmonary Vein Isolation (PVI) with VLCC.
Methods
Consecutive AF patients undergoing PVI with VLCC were prospectively enrolled in our centre between April 2024 and October 2025. Ablation area was visualized using projected 1 mm³ grid points (GRID) or 2 mm projected ablation tags (ABLt) corresponding to each electrode of the VLCC for every ablation. Bipolar voltage maps were performed with VLCC to quantify the lesion areas per PV segment (10-segment model) after PVI. Anatomical maps with GRID or ABLt annotation without voltage data were used to calculate predicted lesion area. The predictive capability of GRID/ABLt was calculated using the formula GRID or ABLt Area in Low Voltage Area/ Total Low Voltage Area and expressed as a percentage.
Results
We enrolled 65 patients (64.5 ± 9.5 years, 55.4% males, 15.3% Persistent AF) and a total of 258 PVs. All patients underwent PVI. Median procedural time was 58 min (45-75), dwelling time 30 min (25-50) and fluoroscopy time 4 min (3-7). GRID and ABLt annotation were consistent with PV lesion area resulting in a Pearson’s correlation coefficient of 0.91 (p < 0.0001) and 0.82 (p < 0.0001), respectively. GRID showed a higher predictive capability of overall PV lesion area compared to ABLt (95.8% vs 77.6%; p<0.0001) and also for all PV segments (p<0.01) (Figure 1). GRID annotation demonstrated a lower bias (0.031) and narrow limits of concordance (0.421- -0.344) compared to ABLt demonstrated a higher bias (-0.33) and larger limits of concordance (0.356 - −1.016).
Conclusions
GRID showed a higher predictive capability of PV lesion area compared to ABLt