Epicardial Fragmentation Mapping in Brugada Syndrome: A Three-Patient Case Series with Literature Review.

Background: Brugada syndrome (BrS) carries a high risk of ventricular fibrillation (VF) despite protective therapy with implantable cardioverter-defibrillators (ICDs). Catheter ablation targeting epicardial substrate in the right ventricular outflow tract (RVOT) has emerged as a promising adjunctive strategy; however, optimal procedural endpoints remain unclear. Objective: To present a case series of three BrS patients who underwent high-density (HD) epicardial substrate ablation assisted by electrogram fragmentation mapping, and to review contemporary evidence on Brugada substrate ablation. Methods: Three symptomatic BrS patients underwent epicardial HD mapping using the EnSite X three-dimensional mapping system and Advisor HD Grid catheter. A dedicated fractionation mapping algorithm was used to identify regions of abnormal electrograms. All spontaneous fractionated or late potentials were ablated until the fragmentation map showed no residual abnormal points. Results: In our three cases, HD mapping localized clusters of low-voltage, fractionated electrograms in the RVOT epicardium, which were successfully eliminated with epicardial radiofrequency ablation. Complete substrate removal resulted in normalization of the Brugada electrocardiographic pattern in all patients and rendered VF non-inducible. Over 6 months of follow-up, no VF recurrence was noted and no ICD therapies were delivered. No major procedural complications were observed. Post-ablation voltage maps remained patchy (reflecting residual scar tissue); however, the fragmentation maps became uniformly clean, supporting their utility as an objective endpoint. Conclusions: This case series demonstrates the feasibility of using fragmentation mapping as an intra-procedural guide and endpoint for Brugada ablation in the absence of drug challenge. Fragmentation mapping appeared to reproducibly confirm complete substrate elimination.