Extremely late recurrences (≥3 years) of atrioventricular nodal reentrant tachycardia: Electrophysiological characteristics of the index and repeat ablation procedures

Abstract Background Catheter ablation is an effective treatment for atrioventricular nodal reentrant tachycardia (AVNRT). However, the characteristics of extremely late (>3 years) recurrences of AVNRT after a successful initial ablation are not fully elucidated. We aimed to explore the electrophysiological characteristics of extremely late recurrences of AVNRT after a successful ablation. Methods From 1991 to 2018, 3311 patients (mean age: 48.7 ± 17.4 years; men: 1328 [40.1%]) who underwent catheter ablation for AVNRT were investigated. Baseline characteristics of the patients, recurrence status, and detailed electrophysiological parameters of the index and repeat ablation procedures were obtained for analysis. Results After a mean follow-up period of 129.5 ± 58.0 months, 65 (2.0%) patients underwent repeat ablation for recurrences of AVNRT, of whom 17 (0.5%) presented with extremely late recurrences. The incidence of transient AV block was significantly higher in patients with extremely late recurrences (5.9%) than in those without recurrences (1.9%) but lower than that in patients with recurrences within Conclusion Recurrences of AVNRT can occur 3 years after a successful initial ablation. The electrophysiological features of the index and repeat ablation procedures differed between patients with extremely late recurrences of AVNRT and those with recurrences within