Characterization of atrial substrate to predict AF ablation success

Abstract Funding Acknowledgements Type of funding sources: Private company. Main source(s): The study has been financially supported by an investigator-initiated research grant Biosense Webster (Study ID – IIS-532) (MRM) Background Left atrial (LA) substrate may have mechanistic relevance for ablation fibrillation (AF). We sought to analyze the relationship between low-voltage zones (LVZ), transition-zones (TrZ) and AF recurrence in patients undergoing pulmonary vein isolation (PVI). Methods conducted a prospective multicenter on consecutive PVI-only approach. LVZ TrZ (0.5-1mV) were analyzed offline high-density electroanatomical maps collected prior PVI. Results 262 (61±11 years, 31% female) with paroxysmal (130 pts) or persistent (132 included. After 28 months follow-up, 73 (28%) experienced recurrence. An extension more than 5% 15% associated (HR=4.4 [2.0-9.8], p<0.001 HR=1.9 [1.1-3.7], p=0.045, respectively). Significant linear association was found left volume index (LAVI) (both p<0.001). One-third had significantly increased LAVI without LVZ. Eight percent despite normal LAVI. Older age, female sex, oncological history characterized this latter subgroup. Conclusions In first PVI, impact outcomes occurs lower burden suggesting that not all LVZs equal prognostic implications. A proportional area moderately decreased voltages accompanies LVZ, continuous fibrotic instead dichotomous division healthy diseased tissue. generally correlates but small subgroup present disproportionate remodeling,