Moderated poster - AVNRT cryoablation in children < 26 kg: efficacy and safety of electrophysiologically guided low voltage bridge strategy

Background and Aim: Recent studies have reported that the low voltage bridge (LVB) strategy is very effective in atrioventricular nodal reentrant tachycardia (AVNRT) ablation. The purpose of our study was to evaluate the efficacy and safety of AVNRT cryoablation in pediatric patients &lt; 26 Kg using the electrophysiologically guided LVB strategy both in the acute phase and in a mid-term follow up. Methods: Thirteen pediatric patients (69% males, mean age 7±1.65 years, mean weight 24.8±1.77 Kg), with previous history of AVNRT confirmed by the transesophageal atrial stimulation, underwent slow pathway cryoablation using the electrophysiologically guided LVB strategy. Results: In 12 patients a typical AVNRT was induced, while 1 patient showed both a typical and an atypical form. An AV “jump” occurred in 46% of patients. One small LVB was found in 7 patients (54%) at the M1-M2 level, in 4 (31%) at P2 or P2-M1 level, in 1(7.5%) at A2 and another 1 (7.5%) at M1 level. Acute success was 100% with an average of 5 cryoablations per patient. No peri-procedural complications occurred. All procedures were performed with near-zero fluoroscopy. No recurrence occurred during the follow up (10.58±10.23 months). Conclusion: AVNRT cryoablation using the electrophysiologically guided LVB strategy seems to be an effective and very safe procedure in small children who are the highest risk patients for this type of ablation.