PO-03-170 INAPPROPRIATE SHOCKS IN PEDIATRIC PATIENTS WITH ICDS

Abstract

Implantable-cardioverter defibrillators (ICDs) can deliver shocks under inappropriate clinical circumstances [including supraventricular tachycardia (SVT)]. Delayed detection programming has been studied in adults to reduce inappropriate shocks, but the data is limited in the pediatric population. Evaluate the incidence and risk factors for inappropriate shocks in patients (pts) <19 years of age at time of ICD implant Retrospective study of pts <19 years of age at time of ICD implant between 2010-2020. Treatment zones were defined as “conventional” if programmed with a threshold of 180bpm for <5 seconds (sec) or 200bpm <3 sec; and “delayed” if 180bpm ≥5 sec, 200bpm ≥3sec or 220bpm ≥1sec. A total of 126 pts were included with a median age of 15 (range 0.5, 18.8) years at first ICD implant. Transvenous devices accounted for 113 (90%), epicardial 10 (8%), subcutaneous 3 (2%); 39 (31%) were for secondary prevention. Diagnoses included cardiomyopathy 62 (49%), channelopathy 21 (17%), congenital heart disease 16 (13%), acquired 7 (6%), and other 20 (15%). Delayed programming was present in 88 (70%) with 98 (78%) having detection thresholds of ≥220 bpm. Appropriate shocks were delivered in 21 (17%) pts, inappropriate 7 (6%), and both 3 (2%). Inappropriate shocks were delivered for sinus tachycardia (3), atrial flutter (2), atrial fibrillation (2) and other SVT (3). There were no shocks for lead malfunction. Conventional programming had a greater but not statistically significant risk for an inappropriate shock (p=0.14). Patients with a history of SVT had a statistically significant increased risk for inappropriate shock (Fig 1) - neither antiarrhythmic use, nor use of ICD discriminators had an effect. Risk for inappropriate shock was 5% at 1 year, 9% at 5 years after implant. Risk for appropriate shock was 4% and 22%, respectively. The majority of children with ICDs are programmed with high detection rates for therapy. The burden of inappropriate shocks is low, with no modifiable risk factors (i.e. antiarrhythmics, treatment zones). The majority of inappropriate therapy resulted from SVT, raising the potential for performing programmed atrial stimulation at implant to identify those patients who may benefit from an early ablation strategy.