A Comparison of AV Nodal Reentrant Tachycardia in Young Children and Adolescents: Electrophysiology, Ablation, and Outcomes.

BACKGROUND: Atrioventricular nodal reentrant tachycardia (AVNRT) typically occurs in adolescents and adults with limited data regarding AVNRT in young children.

METHODS: All patients with AVNRT who underwent electrophysiology study and ablation between 2005 and 2012 were retrospectively studied. Patients were stratified by age <10 years (young AVNRT) or ≥10 years (older AVNRT). Young AVNRT patients were also compared to age-matched patients with orthodromic reentrant tachycardia (ORT).

RESULTS: A total of 275 studies in 272 patients were evaluated including 38 young AVNRT patients (7.7 ± 1.5 years) and 202 older AVNRT patients (14.9 ± 2.1 years). An atrial-His jump ≥50 ms was demonstrated in 56% of young and 64% of older patients. Slow pathway modification was attempted in all but one older patient with acute ablation success achieved in all. RF ablation was the primary ablation modality with cryoablation used in 10 patients (three young and seven older). Recurrences were rare (zero young and three older patients) despite residual AVNRT echo beats postablation in 34% of young and 40% of older patients. One older AVNRT patient (0.5%) required a pacemaker for heart block while no complications occurred in the young patients. Electrophysiologic parameters were comparable to the 35 age-matched young ORT group (7.7 ±1.7 years) in whom supraventricular tachycardia was more inducible.

CONCUSIONS: Slow pathway modification for AVNRT in children resulted in high success and low complication rates, regardless of age. Recurrence of tachycardia was infrequent despite persistence of AVNRT echo beats in 34-40% of patients following slow pathway modification.