BackgroundWolff-Parkinson-White (WPW) syndrome is associated with ventricular dysfunction in the absence of sustained tachyarrhythmias. Our aim was to determine the prevalence of ventricular dysfunction and to assess risk factors associated with this condition. MethodsA single-center retrospective analysis of all patients < 18 years of age with WPW syndrome and normal cardiac anatomy who underwent an electrophysiology study (EPS) ablation over a 14 year period was performed. Patients with an ejection fraction (EF) < 55% were defined as having ventricular dysfunction. ResultsAmongst 305 patients, 14 cases (4.5%) with ventricular dysfunction were identified. In 4/14 (28%) the presenting symptom was heart failure, and only 6/14 (43%) had symptoms of palpitations or documented SVT. The vast majority of patients with dysfunction had right-sided pathways and only two patients had a left-sided pathway locations. Right antero-septal, anterior and anterolateral accessory pathway locations were more common in the dysfunction group. The presence of multiple pathways and pathway characteristics assessed during EPS were comparable between the two groups. ConclusionsThe prevalence of ventricular dysfunction in WPW syndrome in children was 4.5%, and this is seen more frequently with right anteroseptal, anterior and anterolateral pathway locations. Risk analysis identified these pathway locations to be associated with a four-fold risk of developing ventricular dysfunction (OR 4.32[CI 1.38-14.18], p=0.012). Due to this rare complication, serial assessment of ventricular function is recommended regardless of arrhythmia burden and an ablation should be considered in the presence of dysfunction.