Three-dimensional electroanatomically guided slow pathway elimination is associated with procedural improvements and clinical benefit in atrioventricular node reentrant tachycardia patients.

Background: Slow pathway (SP) ablation, in the context of atrioventricular node reentrant tachycardia (AVNRT) treatment could result in either complete elimination or only modification of the SP with ambiguity regarding associated benefits. Three-dimensional electroanatomical mapping (3D-EAM) may be used adjunctively aiming to complete SP elimination. Our purpose was to compare a 3D-EAM-based strategy targeting SP elimination to the conventional fluoroscopic approach with respect to clinical outcomes.

Methods: One hundred and two consecutive AVNRT patients (36 males, mean age 53.2 ± 13.7 years) underwent in two successive periods a conventional fluoroscopic ablation approach ( = 42) or a 3D-EAM-guided ablation focusing on complete SP elimination ( = 60).

Results: Several procedural parameters improved with 3D-EAM use, including fluoroscopy time (2.4 ± 4.7 min vs. 13 ± 4.5 min), dose-area product (1061 ± 3122 μGy × m vs. 5002 ± 3032 μGy × m) and slow pathway elimination frequency (95% vs. 50%, all  < .001). Procedural time was slightly prolonged in the 3D-EAM group (101 ± 31 min vs. 87 ± 24 min,  = .013). Two major complications occurred in the conventional group. Altogether, over a mean follow-up of approximately 2.7 years, recurrence occurred in 6 of 42 (14.3%) in the conventional group as compared to 1 of 62 (1.7%) in the EAM-based group ( = .019). In the Kaplan-Meier analysis, time-to-event was significantly longer for the EAM-based patients ( < .030). Moreover, the EAM-based strategy was associated with less redo procedures' rates (9.5% in the non-EAM group vs. 0% in the EAM group,  = .026).

Conclusions: The present study showed that an EAM-based SP elimination strategy is not only feasible and safe but it is also accompanied by improved clinical outcomes in the setting of AVNRT ablation.