Inappropriate ICD shocks in pediatrics and congenital heart disease patients: Risk factors and programming strategies.

Abstract

Inappropriate implantable cardioverter-defibrillator (ICD) shocks are a common and significant problem in pediatric patients and patients with congenital heart disease (CHD). The purpose of this study was to evaluate the effect of programming high detection rates and long detection duration on inappropriate shocks in this population. We performed a retrospective review of all patients with ICDs at a single pediatric center. Inappropriate shocks were defined as a shock for any rhythm except ventricular tachycardia or fibrillation. A total of 144 patients were included, 63 (44%) with CHD. At implant, mean age and weight were 17 ± 10 years and 57 ± 23 kg. ICDs were single chamber in 35 (24%), dual chamber in 97 (67%), and biventricular in 12 (8%). The mean follow-up duration was 42 ± 39 months. Appropriate shocks occurred in 29 (20.1%) and inappropriate shocks in 14 (9.7%). Causes of inappropriate shocks were supraventricular tachycardia (n = 6), lead malfunction (n = 4), sinus tachycardia (n = 3), and T-wave oversensing (n = 1). The mean ventricular fibrillation detection rate was 222 ± 15 beats/min, and the detection duration was 18 ± 12 beats. Patients with shocks programmed in the ventricular tachycardia zone were more likely to receive an inappropriate shock (P = .03). There were no associations between inappropriate shocks and age or weight at implant, presence of CHD, dual-chamber vs single-chamber device, history of supraventricular tachycardia, or antiarrhythmic use. There were no adverse events as a result of programming. Programming high detection rates and long detection duration resulted in a low rate of inappropriate shocks without associated adverse events in this large cohort of pediatric and CHD patients with ICDs.