Empiric slow-pathway ablation results for presumed atrioventricular nodal reentrant tachycardia in pediatric patients.

BACKGROUND: In pediatric patients with documented narrow QRS tachycardia that is suggestive of atrioventricular nodal reentrant tachycardia (AVNRT) and not inducible in electrophysiological study (EPS), empiric slowpathway ablation (ESPA) may be considered. There is limited data in children about this topic. METHODS: Seventy-nine patients who underwent cryoablation and/or radiofrequency ablation (RFA) for presumed AVNRT between January 2010 and January 2020, with no inducible tachycardia and no other tachycardia mechanisms during EPS, were included in this study. RESULTS: The age was between 6 and 18 years. All patients had no structural heart disease. Preablation exhibited sustained SP conduction for all patients. In all cases, the ablation end points were prolongation in wenckebach cycle length (WBCL) with loss of cross and/or jump, and/or echo beat. The end points were not achieved in two patients. Overall, the mean basal WBCL increased to 351 ms (240-500 ms) from 301.3 ms (180-420 ms), evident in the non-recurrence group. Nine patients had a transient AV block that improved. We followed the patients without medication for about 46.9 months (8 months to 10 years). Palpitations occurred again in 9 of 77 patients (clinical recurrence rate 9/79 - 11.3%). The documented ECG recurrence rate was 1.2% (1/79). In the non-recurrence group, WBCL prolongation was higher and mean age was lower than in the recurrence group (13.075 vs. 15.33 years). CONCLUSION: In cases with presumed AVNRT, ESPA seems to be a reasonable and safe way. In our study, we found our procedural success rate as 97.4% and follow-up recurrence rate as 12.6% (9+1/79).