RESUMO
BACKGROUND: Late potential elimination has been proposed as a surrogate endpoint for scar-related VT ablation procedures. The characteristics, distribution, and predictors of persistent LPs (pLP) after ablation have not been studied. OBJECTIVE: We sought to characterize the spatial distribution and features of pLP after catheter ablation of VT substrate with high-resolution mapping. METHODS: Cases of scar-related VT ablation with adequate pre- and post-ablation electroanatomical maps (EAM) acquired exclusively using a high-density grid (HDG) catheter were reviewed from 2021-2023. RESULTS: A total of 62 EAM (pre- and post-ablation) from 31 cases using HDG were reviewed. Persistent late potentials (pLP) were observed in 19 cases after ablation (61%). New LP, spatially distinct from pre-ablation LP, at the periphery of the ablation area comprised the majority of pLP (16/19, 84%). Isolated pLP were more prevalent than fractionated pLP with a median amplitude of 0.26mV (0.09-0.59mV). The presence of pLP was associated with a significantly lower LVEF and septal ablation but not low voltage, late potential, or ablation area as compared to absence of pLP (22.8±7.8% vs 31.5±8.0% [p =0.008] for LVEF, and 83% vs 44% [p = 0.033] for septal ablation). CONCLUSIONS: Formation of spatially distinct new LP after targeted VT ablation is common especially in patients with lower LVEF and septal substrate independent of ablation burden. This finding highlights the limitations of complete LP elimination as an endpoint to VT ablation procedures.
