Spontaneous Resolution of Ventricular Pre-Excitation During Childhood: A Retrospective Study

<b>Background/Objectives:</b> Ventricular pre-excitation (VP) increases the risk of sudden cardiac death among children. While transcatheter ablation could potentially be therapeutic, it is not without risk, especially in smaller children. Accessory pathways (APs) may spontaneously lose anterograde conduction properties over time, making invasive treatment unnecessary. We aim to investigate the probability of spontaneous loss of VP during childhood, as well as the potential factors that may be associated with VP resolution. <b>Methods:</b> We conducted a retrospective study of patients with VP diagnosed before 12 years of age and referred to two Northern Italian tertiary care hospitals between 1993 and 2021. Patients with complex congenital heart disease were excluded. Our primary objective was to determine the likelihood of spontaneous resolution of VP. <b>Results:</b> Overall, 153 patients were included, with a median age at first diagnosis of 4.9 years (25th-75th percentile: 75 days-8.4 years) and a median follow-up of 4.9 years (25th-75th percentile: 1.8-8 years). Through left truncated Kaplan-Meier analysis, we estimated that anterograde conduction would persist in 53% and 33.8% of patients at the age of 1 and 16 years, respectively. Our findings revealed that the absence of symptoms and intermittent VP were associated with a higher likelihood of VP resolution. It is noteworthy that no major arrhythmic events were reported. <b>Conclusions:</b> Our study strongly supports the implementation of a conservative strategy in younger children with VP. Our findings indicate that a significant proportion of pediatric patients may experience spontaneous resolution of VP in the early years of their lives, making any invasive treatment unnecessary.