Catheter Ablation of Coronary Sinus Accessory Pathways in the Young

BACKGROUND

Accessory atrioventricular pathways (AP) are the most common tachycardia substrate for supraventricular tachycardia (SVT) in the young. Endocardial catheter ablation of AP may be unsuccessful in up to 5% due to a coronary sinus location.

OBJECTIVE

Data on ablation of accessory pathways within the coronary venous system (CVS) in the young is sparse.

METHODS

Analysis of feasibility, outcome, and safety in patients ≤18 years with coronary sinus accessory pathways (CS-AP) and catheter ablation via CVS in a tertiary pediatric electrophysiological referral center (05/2003-12/2021). Control group adjusted for age, weight, and pathway location was established from patients of the prospective European Multicenter Pediatric Ablation Registry who all had endocardial AP ablation.

RESULTS

24 individuals had mapping and intended AP ablation within the CVS (age: 2.7-17.3 years, body weight: 15.0-72.0 kg). Due to proximity to coronary artery, ablation was withheld in 2/24. Overall procedural success was achieved in 20/22 (90.9%) study patients and in 46/48 (95.8%) controls. Coronary artery injury after RF ablation was noted in 2/22 (9%) study patients and in 1/48 (2%) controls. In CVS patients repeat SVT occurred in 5/22 (23%) during a median follow-up of 8.5 years, 4/5 underwent reablation resulting in 94.4% overall success. Controls were free from SVT during follow-up of 12 months as defined by registry protocol.

CONCLUSIONS

Success of CS-AP ablation in the young was comparable to endocardial AP-ablation. Substantial risk of coronary artery injury should be considered when CS-AP ablation is performed in the young.