Abstract / Summary
Background: Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. While pulmonary vein isolation (PVI) remains the cornerstone of AF ablation, the optimal method for confirming complete acute isolation remains uncertain. This study evaluated the diagnostic value of pulmonary vein (PV) pacing compared with repeat three-dimensional (3D) electroanatomical mapping following wide antral circumferential ablation (WACA). Methods: In this prospective observational study, 58 patients with paroxysmal or persistent AF undergoing bilateral WACA at the University Heart Center Ulm between November 2023 and April 2025 were included. Following successful PVI, pacing was performed from each PV and the corresponding carina region using a maximal stimulation output of 20 mA. Subsequently, comprehensive 3D re-mapping was performed to reassess electrical conduction. Results obtained from pacing maneuvers were compared with repeat mapping findings. Results: The study population had a median age of 73 (62.7–78.2) years and a median body mass index of 26.8 (24.0–29.9) kg/m2. Median left atrial diameter was 4.8 (4.3–5.5) cm, and moderate to advanced atrial fibrosis was present in approximately one-third of patients. For the left-sided PVs, pacing assessment alone was associated with a significantly higher proportion of false-negative results compared with 3D re-mapping (left upper PV: p = 0.039; left inferior PV: p = 0.012). In contrast, no significant differences were observed for the right PVs. Evaluation of the carina regions showed a similar pattern, with a significant discrepancy on the left side (p = 0.002) but not on the right side (p = 0.453). Conclusions: PV pacing alone may not reliably identify residual conduction within the left PVs and left carina after WACA. Additional 3D re-mapping appears valuable in these regions to detect persistent conduction gaps that could otherwise remain unnoticed. For right-sided PVs, pacing-based assessment may provide sufficient confirmation of acute isolation in many cases. These findings support a complementary use of both techniques to improve procedural verification of PVI. Larger prospective studies are warranted to confirm the observed results and determine their clinical implications.