Predictors of long-term success in catheter ablation of atrioventricular nodal reentrant tachycardia: a multivariate regression analysis

Background: To investigate the predictors of long-term success after catheter ablation of atrioventricular nodal reentrant tachycardia (AVNRT). Methods: One-hundred and fourteen consecutive patients underwent slow pathway ablation using anteroseptal (n=24), midseptal (n=65) and posteroseptal approach (n=25). The correlation between ablation approaches, electrophysiological characteristics during and after ablation and the recurrence rate of AVNRT was analyzed by a multivariate regression analysis. Results: During ablation, transient AV block in the anteroseptal, midseptal and posteroseptal approach occurred in 8.3, 4.6 and 0%, respectively (P<0.01). AVNRT recurred in seven patients after 5 years follow-up. Five recurrences (20.8%) were from anteroseptal approach group and two (3.1%) were from midseptal approach group. Multivariate regression analysis revealed that anteroseptal ablation approach and residual dual atrioventricular nodal pathway following apparently successful ablation were the predictors for recurrence of AVNRT (R=0.645, P<0.001). Conclusion: Anteroseptal approach of slow pathway ablation is associated with a higher incidence of transient AV block and AVNRT recurrence than other approaches. Residual dual atrioventricular nodal pathway after apparently successful ablation also carries a high risk of recurrence.