Midseptal and Anteroseptal Accessory Pathway Ablation in Children

<b>Objectives:</b> The goal of this study is to document outcomes of ablation for high-risk accessory pathways in paediatrics using 3D mapping systems with minimal to zero fluoroscopy. <b>Methods:</b> It is a cross-sectional, multicentre study, conducted between 2013 and 2023, and involving four different centres in Hungary, Croatia, Kuwait, and Slovenia. <b>Results:</b> A total of 128 procedures were performed on 111 patients. The cohort included 57.8% anteroseptal (AS) pathways and 42.2% midseptal (MS) pathways. The mean follow-up time was 2.0 ± 2.1 years. Cryoablation was used in 72.7% of the cases, and radiofrequency ablation was used in 27.3%. The EnSite Precision™ Cardiac Mapping System was the predominant system used. The overall acute success rate was 89.1%, with recurrence rates at 17.2% with similar results regardless of the type of energy used. The success rate was not significantly different between AS and MS substrates. The age and weight of the patient had no bearing on the outcomes (median age and weight were 13 years and 52 kg, respectively). The complications rate was at 4.69% and included transient AV block (three patients), hematoma (one patient), right bundle branch block (one patient), and possible permanent complete AV block (one patient). Fluoroscopy was utilized in 18 cases, with a fluoroscopy time mean of 3 min and 45 s. <b>Conclusions:</b> MS and AS AP in paediatric patients can be treated effectively with either RF or cryoablation and with a low dose of radiation using 3D mapping systems, with excellent acute success rates and low complication rates.