Cryoablation Versus Radiofrequency Ablation for Atrioventricular Nodal Reentrant Tachycardia in Children: Long-Term Results

Introduction: Cryoablation is used increasingly for the treatment of atrioventricular nodal reentrant tachycardia (AVNRT). We sought to compare the long-term outcomes of cryoablation (Cryo) vs. radiofrequency (RF) ablation for the treatment of AVNRT in children. Methods: Two groups of consecutive patients were analyzed retrospectively: the RF group, 20 patients (60% males, mean age 13.25 +/- 2.59 years), and the Cryo group, 20 patients (55% males, mean age 12.17 +/- 3.07 years). Follow up was 52.7 +/- 16.5 months for the RF and 32.8 +/- 11.9 months for the Cryo group. Results: Acute success rates (100% for RF vs. 90% for Cryo), procedural times (147.75 +/- 37.15 min for RF vs. 184.4 +/- 75.59 min for Cryo), and fluoroscopy times (10.9 +/- 6.46 min for RF vs. 6.41 +/- 6.92 min for Cryo) were not statistically significantly different between the two groups. The number of lesions was significantly higher in RF than in Cryo (8.85 +/- 6.63 vs. 3.6 +/- 1.9, p=0.007). Transient AV block during ablation occurred in 1 patient in each group. No permanent AV block was observed. Recurrence rate was 10% in the RF and 27.7% in the Cryo group (p=0.222) occurring up to 14 months after the procedure. Conclusion: Cryoablation is safe and effective for the treatment of AVNRT in pediatric patients, but there is a tendency for higher recurrence rates compared to radiofrequency ablation. Techniques to reduce recurrence rates after cryoablation are needed.