J Card Surg. 2020;1–6. wileyonlinelibrary.com/journal/jocs © 2020 Wiley Periodicals, Inc. | 1 DOI: 10.1111/jocs.14506 ORIGINAL ARTICLE Institutional experience of healthy pediatric patients presenting with atrial fibrillation who had an electrophysiology study William B. Orr MD | Chad Stanley BS, MS | Aarti Dalal DO | Bridget Zoeller MD | George F. Van Hare MD, FHRS | Jennifer N. Avari Silva MD, FHRS Division of Pediatric Cardiology, Saint Louis Children's Hospital, Washington University School of Medicine, Saint Louis, Missouri Correspondence Jennifer N. Avari Silva, MD, Washington University School of Medicine, 1 Children's Place, CB 8116 NWT, Saint Louis, MO 63110. Email: jennifersilva@wustl.edu Abstract Introduction: Atrial fibrillation (AF) is a very common tachyarrhythmia with in- creasing prevalence with age, but uncommon in the pediatric population. Under- standing that AF increases comorbidities make the need for investigation and potential elimination of alternate etiologies in pediatric AF patients critical. The objective of this study was to review our institutional data and compare our findings with previously documented adult AF risk factors to pediatric patients while also identifying which patients had alternate electrophysiology diagnoses amenable to transcatheter ablation. Methods: A retrospective chart review was performed identifying AF patients who were less than 21 years old, had no significant congenital cardiovascular anomalies, a documented episode of AF on electrocardiogram and underwent invasive electro- physiology study (EPS). Results: Nineteen patients were identified over a 9‐year period of time finding a male predominance (74%), the average age of 14.95 ± 4.17 years, the average weight of 78.5 ± 31.4 kg, and average body mass index of 26.8 ± 6.87 kg/m 2 . Preprocedural left atrial volumes made on echocardiograms demonstrated a mean of 33.96 ± 16.35 mL/m 2 (Z‐scores -0.81 ± 1.50), indicating no dilation. Five of nineteen patients (26%) had addi- tional electrophysiologic diagnoses during EPS, including atrioventricular reentrant tachycardia (n = 2, 10%) and atrioventricular nodal reentrant tachycardia (n = 3, 16%). Four patients underwent successful ablation with no documented or clinical AF recurrence. Conclusions: Adult risk factors of male predominance and obesity were seen in pediatric AF patients, while left atrial enlargement was not. Twenty‐one percent of the pediatric AF patients who had additional electrophysiologic substrates and successful ablations resulted in no further clinical episodes of AF. This suggests that pediatric patients presenting with AF might benefit from an EPS as part of a com- plete evaluation. KEYWORDS atrial fibrillation, electrophysiology study, pediatrics