Safety of Ablation Within the Coronary Venous Sinus in Pediatric Patients

BACKGROUND: Catheter-based ablation in the coronary venous sinus (CS) can be associated with inadvertent coronary artery (CA) injury. However, a significant gap remains in the literature with regard to safety of such ablation in pediatrics. OBJECTIVES: The primary aim of this study was to describe the safety of catheter-based ablation within the CS. Secondary aim was to describe the practice pattern of ablation energy source within the CS among pediatric centers. METHODS: This was a multi-center, retrospective study over a period of 20 years (1999-2019) involving seven centers. Pediatric patients (≤ 21 years of age) undergoing ablation within the CS were included. RESULTS: A total of 211 patients were included (median age: 14 [IQR: 10.5, 16.0]). Accessory pathways were the target in almost 90% of the patients with cryoablation in 55%, nonirrigated RF in 40% and irrigated RF in 6%. Only 16% had coronary arteriogram done before RF. There was a single patient who had CA injury, in the form of a transient spasm of the left circumflex CA following RF in the proximal CS. There was transient high-grade AV block in six patients (2.8%) who either had RF or cryoablation. There was no permanent AV block. CONCLUSION: The use coronary arteriogram before RF in the CS is infrequent, although acute CA injury appears to be rare following such ablation. Transient heart block is not uncommon, and the operators need to be vigilant in monitoring AV nodal conduction.