Linear Lesion Cryoablation for the Treatment of Atrioventricular Nodal Re-entry Tachycardia in Pediatrics and Young Adults

Abstract

Radiofrequency (RF) ablation is a relatively safe and effective method for treatment of atrioventricular nodal re-entry tachycardia (AVNRT), but carries a 1-2% risk of AV nodal injury. Cryothermal ablation reduces the risk of AV block, but has had decreased procedural success and increased recurrence of tachycardia. We sought to evaluate the technique of linear lesion cryoablation (LLC) for treatment of AVNRT. Single institution retrospective cohort study. Each patient underwent slow pathway modification using either RF, single lesion cryoablation, or LLC. Procedural success, recurrence, freedom from tachycardia 12 months following ablation and fluoroscopy time were compared between ablation methods. A total of 125 patients, median age 15.5 (4.7-23.1) years, underwent ablation: 32 RF energy, 31 single lesion cryoablation, 62 LLC. Procedural success was obtained in 94% of the LLC group compared to 58% using single lesion cryoablation (P ≤ 0.001). Ninety-seven percent of the LLC group was free from tachycardia recurrence, significantly higher than with single lesion cryoablation (68%, P = 0.001) and equal to that of RF (97%, P = NS). Fluoroscopy time was reduced in the LLC group compared to both single lesion and RF groups (P = 0.02). There was no permanent AV nodal injury in the cryoablation groups. LLC is an effective means of treatment for AVNRT and is associated with significantly improved procedural success and freedom from recurrence compared to single lesion methods, while at the same time obtaining equivalent efficacy to RF.