PO-674-05 THE SHOCKING PRACTICES OF PEDIATRIC ELECTROPHYSIOLOGISTS: CONTEMPORARY DFT DATA FROM CIED REGISTRY

Abstract

Defibrillator threshold (DFT) testing is no longer recommended except in certain circumstances. Data on current national practice pertaining to DFT testing in pediatrics is scarce. To report current implant characteristics, DFT testing practice, and intraprocedural events in pediatric patients undergoing implantable cardiac defibrillator (ICD) placement. We leveraged the pediatric cardiac implantable electronic devices (CIED) registry, a retrospective multicenter study endorsed by PACES, to identify patients (age≤21) who underwent ICD placement between 2017 and 2020. Among 705 patients, 51 underwent new ICD implantation. Median age and median weight at implant were 16 years (IQR 14-18) and 62 kg (53-78) respectively. Cardiomyopathy was diagnosed in 28, congenital heart disease (CHD) in 8, idiopathic VT/VF in 8, channelopathy in 5, and other in 2. An ICD was implanted for secondary prevention in 18 patients. Type of implants were as follows: transvenous in 39, subcutaneous in 8, and epicardial in 4. DFT status was known in 49 patients, of whom 30 (61%) underwent testing. DFT testing was performed in all patients who had a subcutaneous device but there was no difference in those with transvenous vs. epicardial leads (53% vs. 66%, p=0.63). DFT testing was less likely in patients seen at a freestanding Children’s Hospital (48% vs. 87%, p=0.012) but did not vary between diagnoses (CHD 59%, cardiomyopathy 62%, channelopathy 60%, and idiopathic ventricular fibrillation 75%, p=0.68) or type of cardiomyopathy (hypertrophic cardiomyopathy vs. all other types, 62% vs. 55%, p=0.67). Age, weight, mild ventricular dysfunction or greater, history of cardiac arrest, or implant provider were not associated with DFT testing. DFTs failed in 2 patients: inability to induce VT/VF in 1 and inability to defibrillate with an acceptable safety margin in 1. There were no reported complications with DFTs. DFT testing is still performed at implant in the majority of transvenous devices in pediatric patients. Presence of CHD or hypertrophic cardiomyopathy was not associated with higher DFT testing rates. Freestanding children’s hospitals were less likely to perform DFTs.