Transcatheter cryoablation for atrioventricular nodal reentrant tachycardia and septal accessory pathways: Experience from a tertiary center

INTRODUCTION AND OBJECTIVES: For atrioventricular nodal tachycardia (AVNRT) and right-septal anatomically high-risk accessory pathways (AP) with risk of atrioventricular (AV) block, cryoablation is accepted as a safer option. The aim was to evaluate the efficacy, safety and recurrence rates of focal catheter cryoablation for the treatment of AVNRT and right-sided septal AP. METHODS: We performed a retrospective single-center study of patients undergoing focal cryoablation between January 2007 and May 2025 with the electrophysiologic diagnosis of AVNRT or AP based on electrophysiological criteria. Clinical, electrophysiological, and follow-up data were systematically collected from hospital electronic medical records. Clinical characteristics, procedural data, safety and recurrence were analyzed. RESULTS: We included 49 patients, median age 28 years (interquartile range IQR 17-50) who had been referred for the procedure due to Wolff-Parkinson-White syndrome (WPW - 55%); documented tachycardia (37%) and recurrent palpitations in the remaining patients. Seven patients had previously undergone radiofrequency ablation, with arrhythmia recurrence. Six patients were >65 years and had pre-existing slight conduction system abnormalities. Electrophysiologic evaluation revealed AVNRT in 30.6% and right-septal AP in 69.4% (Table 1). Acute procedural success was 100% in AVNRT (15/15 patients) and 77% in accessory pathways (26/34 patients). Unsuccessful cases involved electrophysiologically low-risk AP in oligosymptomatic patients, one of whom had transient AV block during application. All cases with a history of previous unsuccessful ablation/recurrence achieved acute success with cryoenergy. Noone experienced further recurrences during follow-up (FUP). Zero-fluoroscopy procedures were performed in 24% of cases. No major complications were reported. Over a median FUP of 13 (IQR 1-60) months, recurrence occurred in 5 patients (12.2%; 2 with AVRNT and three with AP). CONCLUSIONS: Cryoablation is an effective and safe approach for the treatment of patients with supraventricular arrhythmias involving the perinodal area, with good acute success rates, low recurrence rates and a favorable safety profile. These findings are especially relevant in younger patients where minimizing the risk of permanent AV block is critical. These results also suggest a role for cryoablation in older patients with baseline conduction system abnormalities.