Titolo della tesi: Transcatheter Ablation of Paroxysmal Atrial Fibrillation Guided by Unipolar Signal: Impact on Efficacy and Comparison with Ablation Index
Abstract
Background
Pulmonary vein isolation (PVI) using radiofrequency ablation (RFA) serves as a cornerstone treatment for drug-resistant atrial fibrillation (AF). Ablation Index (AI) acts as an indicator of the quality of individual ablation points during circumferential ablation of atrial fibrillation. Established AI target values, which differ for the anterior and posterior atrial walls, are employed as "local endpoints." However, these target values do not take into account the real thickness of the atrial wall. Recent studies have underscored the importance of real-time unipolar electrogram (U-EGM) modification, specifically the elimination of the negative component, as a pertinent "local endpoint" for transmural lesion formation during PVI. We aimed to compare the outcomes of atrial fibrillation ablation guided by U-EGM versus AI.
Methods
156 patients with paroxysmal AF were randomized to U-EGM (78) or AI-guided ablation (78). In the U-EGM group, radiofrequency was extended 5 seconds after a positive U-EGM while concurrently recording the corresponding Ablation Index values. In the AI group, target values were AI 500 for the anterior and AI 380 for the posterior wall.
Results
Both groups showed similar sinus rhythm maintenance. The U-EGM group had significantly lower average AI values (p < 0.001) and shorter ablation times (p < 0.001). No significant differences were found in RF points, fluoroscopy time, and complication rates.
Conclusion
U-EGM and AI guidance for PVI yielded comparable sinus rhythm maintenance. Notably, local endpoints in ablation guided by U-EGM modification were achieved in significantly less time compared to conventional AI-guided ablation. Moreover, the contextual AI values recorded during U-EGM-guided ablation were consistently lower than current literature benchmarks. These findings suggest that U-EGM-guided ablation may offer an efficient and potentially accurate methodology for PVI in AF ablation.