Abstract
Objectives: We sought to investigate the relationship between the size of the left atrial (LA) isolated surface area (ISA) after pulmonary vein antrum isolation (PVAI) for paroxysmal atrial fibrillation (AF) and rhythm outcome after a 12 month follow up. Methods: One-hundred-one consecutive patients with paroxysmal AF after PVAI were enrolled. ISA was expressed as the proportion of isolated surface areas (cm2), i.e. the isolated antral regions of the LA excluding the PVs, to the sum of the surface areas of the antral regions plus the surface of the posterior wall (cm2) taking into consideration the individual antral anatomy. All surface areas were assessed using a special software of the NavX system. Patients were arbitrarily divided into four groups according to ISA (Group I: <50%, group II: 50 to <60%, group III: 60 to <70%, group IV: ≥70%). Results: In Kaplan-Meier analysis, recurrence rate was significantly lower in group III and group IV, respectively, as compared to group I (p<0.03 for both comparisons). According to receiver-operator characteristic curve analysis, the optimal cutoff value of ISA was 55%. Conclusion: After 12 months, a larger ISA was associated with a significantly lower AF/MRT recurrence rate. ISA ≥55% might serve as a predictor for long-term success after PVAI.
