Abstract 19031: Utilization and Outcomes of Anti-Tachycardia Pacing Therapy in Children and Young Adults With Implantable-Cardioverter Defibrillators
Background: Inappropriate and unnecessary ICD shocks are a concern in the growing pediatric device population. Historically, ICDs have been programmed as “shock boxes,” with a single therapy zone for ventricular fibrillation (VF). Adult trials have demonstrated safe shock reduction by programming a second zone for ventricular tachycardia (VT), with anti-tachycardia pacing (ATP) as initial therapy. The utilization and outcomes of ATP therapy have not been described in the pediatric population.
Methods: Subjects ≤ 30 years of age with ICDs implanted at a single tertiary pediatric center between 9/30/2009 and 9/30/2012 were included. Patient characteristics, ICD programming, and outcomes were retrospectively reviewed.
Results: 45 patients underwent ICD implantation at a mean age of 13.9 ± 4 years (55% primary electrical disorder, 36% cardiomyopathy, 9% congenital heart disease). A primary prevention indication was present in 64% (n=29). A single VF zone with shock therapy only was programmed in 32 patients (71%). Thirteen patients (29%) had a second VT zone with ATP as initial therapy. Of 11 patients with a history of monomorphic VT, 45% (n=5) had two zone programming. ATP during charging was programmed in the VF zone in 91% of devices. At a median follow-up of 19.2 months (IQR 8.4-26.1 months), 37 events (2 VF, 28 monomorphic VT, 7 polymorphic VT) met criteria for therapy in 4 patients; 16 (43%) events were treated with shocks, including 9 that required multiple shocks; 21 (57%) events, all monomorphic VT, were pace-terminated in 2 patients. ATP was successful in 21 of 22 (95%) attempts. In 3 events, VT terminated with ATP while charging, so shocks were aborted. There were no syncopal events due to delay in shocks by ATP failure. There was no difference in the number of inappropriate shocks between single (n=6) and two zone (n=4) programming groups, although 2 patients with two zone programming were shocked for sinus tachycardia in the VT zone.
Conclusions: The pediatric ICD population is heterogeneous, making it difficult to adopt a uniform programming strategy. ATP can prevent unnecessary shocks in children with monomorphic VT. Two zone programming should be considered for patients at risk for monomorphic VT.
- © 2013 by American Heart Association, Inc.