Radiofrequency catheter ablation of atrioventricular nodal reentrant tachycardia in children aided by the LocaLisa mapping system.
OBJECTIVE
In young patients, slow pathway ablation for treatment of atrioventricular nodal reentrant tachycardia (AVNRT) carries a small but definite risk of permanent AV block. The aim was to assess the efficacy of slow pathway ablation aided by the LocaLisa mapping system.


METHODS
Radiofrequency (RF) modification of the slow AV nodal pathway was performed in 26 children < 19 years of age (median age 9.8 years, range 3-18.9). Three measures to limit the risk of AV block were applied: (1) use of LocaLisa, a non-fluoroscopic mapping system, to determine and mark the location of the AV node/His bundle axis, and monitor ablation catheter position, (2) continuous atrial stimulation during RF delivery to monitor AV conduction, and (3) gradual increase of RF power during RF ablation.


RESULTS
AVNRT was rendered non-inducible in all patients. Dual AV physiology was abolished in 24/26 patients; 2 patients had single atrial echoes at the end of the procedure. At follow-up, AVNRT recurred in 3 patients (including the above 2), necessitating a second procedure. The median number of RF applications was 4 (3-8); median fluoroscopy time was 16 (7-33)min. One patient developed transient second-degree AV block, with full recovery within 6 weeks of the procedure.


CONCLUSIONS
RF modification of the slow AV nodal pathway in children can be safely accomplished, achieving the ideal end-point of abolishing dual AV physiology, aided by use of the LocaLisa mapping system.
Kammeraad
Janneke
J
University Medical Center, Utrecht, The Netherlands.
Udink ten Cate
Floris
F
Simmers
Tim
T
Emmel
Mathias
M
Wittkampf
Fred H M
FH
Sreeram
Narayanswami
N
D000293:Adolescent; D000367:Age Factors; D017115:Catheter Ablation / Q000379:methods*; D002648:Child; D002675:Child, Preschool; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006329:Heart Conduction System / Q000503:physiopathology; D006801:Humans; D008297:Male; D013611:Tachycardia, Atrioventricular Nodal Reentry / Q000503:physiopathology / Q000601:surgery*