title: Cryoablation of accessory pathways in the coronary sinus in young patients: a multicenter study from the Pediatric and Congenital Electrophysiology Society's Working Group on Cryoablation.
abstract: BACKGROUND
  This is a multicenter retrospective study evaluating the immediate- and mid-term outcomes of cryoablation of accessory pathways in the coronary sinus in children or in patients with congenital heart disease.
  
  
  RESULTS
  Twenty-one patients (median age 13.0 years, range 2-40) from six institutions were included. The accessory pathways were concealed in 11 and manifest in 10. Of 12 patients who had coronary sinus angiography, two had large coronary sinus diverticula, one had a dilated coronary sinus due to a left superior vena cava to coronary sinus, and one had a "pouch" at the mouth of the coronary sinus. Six patients underwent ablation procedures with cryoablation alone, while in the remaining 15 patients, both cryoablation and radiofrequency ablation were utilized. The ablation procedure included left-sided endocardial mapping via a retrograde or transseptal approach in 13 (62%). Procedural success was achieved with cryoablation in the coronary sinus in 15/21 (71%). Four patients (19%) had successful radiofrequency ablation at the right or left posterior septum. Two patients (10%) had unsuccessful procedures. Of the 15 patients with initially successful cryoablation procedures, six (40%) had arrhythmia recurrences at a median of 17 days (range 1-120). Recurrences could not be explained by differences in patient or procedural variables.
  
  
  CONCLUSIONS
  Cryoablation in the coronary venous system in young patients is feasible but associated with a high arrhythmia recurrence rate. Cryoablation techniques and/or equipment need to be improved in order to safely create more permanent lesions in this arrhythmia substrate.
authors.affiliation: Department of Pediatrics, Division of Cardiology, University of California, San Francisco, California 94143-0632, USA. kathryn.collins@ucsf.edu
authors.forename: Kathryn K
authors.initials: KK
authors.lastname: Collins
authors.forename: Edward K
authors.initials: EK
authors.lastname: Rhee
authors.forename: Joel A
authors.initials: JA
authors.lastname: Kirsh
authors.forename: Bryan C
authors.initials: BC
authors.lastname: Cannon
authors.forename: Frank A
authors.initials: FA
authors.lastname: Fish
authors.forename: Anne M
authors.initials: AM
authors.lastname: Dubin
authors.forename: George F
authors.initials: GF
authors.lastname: Van Hare
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D003330:Coronary Vessel Anomalies / Q000150:complications / Q000175:diagnosis / Q000601:surgery*; D003452:Cryosurgery / Q000379:methods*; D022062:Electrophysiologic Techniques, Cardiac / Q000379:methods; D005500:Follow-Up Studies; D006329:Heart Conduction System / Q000601:surgery*; D006801:Humans; D012189:Retrospective Studies; D013610:Tachycardia / Q000175:diagnosis / Q000209:etiology; D016896:Treatment Outcome