General anaesthesia compared to conscious sedation for catheter ablation of atrioventricular nodal reentrant tachycardia in adolescents

Abstract Introduction Atrioventricular nodal reentrant tachycardia (AVNRT) is one of the most common types of supraventricular tachycardia (SVT) in adolescents, with catheter ablation (CA) for slow pathway modification being the preferred treatment for symptomatic patients. For safety and comfort, ablation in paediatric patients is typically performed under general anaesthesia (GA). However, GA can contribute to prolonged procedural time and extended hospital stays. Alternatively, ablation under conscious sedation (CS) has been safely performed in adolescents, though data on its procedural and long-term outcomes remain limited. Purpose To characterise AVNRT ablation in adolescents and evaluate long-term outcomes and complications in ablations performed under CS compared to those under GA. Methods We conducted a single-centre retrospective cohort study, including all patients aged 12 to 18 who underwent CA for AVNRT between 2016 and 2023. Patients with congenital heart disease, severe comorbidities or accessory pathways were excluded. Results A total of 58 patients underwent CA during the assessment period, with a mean age of 15.3 ± 2.19 years. The median weight was 56 kg (IQR 17 kg), and 59% were female. SVT was documented in 90% of cases. Additionally, 84% of patients were on antiarrhythmic medication: 67% were receiving beta-blockers alone, 14% were on a combination of beta-blockers and flecainide, and 3% were on flecainide alone. All patients underwent radiofrequency CA. In 55% of the procedures, patients received GA, and an electroanatomic mapping was performed in 76% of cases. Typical AVNRT was observed in the majority of patients (98%). Patients in the GA group were younger (mean age 14.4 vs. 16.3 years, p < 0.001) and had a lower median weight (56 kg vs. 65 kg, p = 0.042). Procedure duration tended to be longer in the GA group (65 vs. 51 minutes, p = 0.058), although fluoroscopic time (0.8 vs. 0.6 minutes, p = 0.791) and radiation dose (32 vs. 27 µGym², p = 0.881) were similar between the groups. Over a median follow-up of 3.5 years, AVNRT recurrence rates (9.1% in the GA group and 6.3% in the CS group, p = 0.477) and repeat ablation rates (4.5% in the GA group and 6.3% in the CS group, p = 0.671) were similar. No major complications were observed; however, two cases of first-degree AV block occurred in the GA group, while none were reported in the CS group. Conclusion Our study suggests that AVNRT CA in adolescents can be effectively performed under CS, with high procedural success and a low risk of complications or recurrence.