Acute Success of Cryoablation of Left-Sided Accessory Pathways: A Single Institution Study

Objective: To compare the acute success and recurrence rate of cryoablation for left-sided accessory pathways (AP) with controls who underwent radiofrequency ablation (RFA) at the same institution.
Background: Catheter cryoablation of supraventricular tachycardia (SVT) is considered to be a safer alternative a compared with RFA. At our institution, cryoablation has become the primary interventional modality for all APs. The reported success rates of cryoablation for AP-mediated tachycardia have generally been less favorable than for RFA. However, the location of AP may influence cryoablation outcome. Furthermore, there are little data available on cryoablation of left-sided pathways.
Methods: A chart review was performed for all patients undergoing cryoablation between August 2005 and August 2007. Twenty-nine patients (mean age 13 years, range 6–18 years) were identified with SVT secondary to left-sided AP. The data collected included patient age, height, weight, date of procedure, mapping, ablation and procedure time, pathway location, success, and recurrence. Cryoablation was performed via a transseptal approach. Procedural success and recurrence rate were compared with our most recent 28 patients undergoing RFA ablation.
Results: Procedural success was achieved in 97% of patients in the cryoablation group, compared with 100% in the RFA control group. Recurrence rate in the cryoablation group was 1 of 24 (4.2%) patients compared with 4 of 28 (14%) patients in the RFA group over 12 months.
Conclusion: Cryoablation can be safely and effectively used in the treatment of left-sided AP. Long-term outcomes remain to be seen.