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. No-one 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%; two 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.