Abstract
<title>Abstract</title> <p> <bold>Objective</bold> To evaluate the relationship between electroclinical features of epilepsy and cardiac autonomic function, assessed through heart rate variability (HRV), in children and youths with paediatric-onset epilepsies. <bold>Materials and Methods</bold> We prospectively enrolled patients with epilepsy aged 3–25 years who underwent polygraphic EEG recordings, analysing HRV in a 5-minute resting ECG segment. Nine indices were examined, including time-domain, frequency-domain, and nonlinear measures. Associations between HRV parameters and clinical variables were assessed using Spearman correlations and linear regression models adjusted for age and sex. Principal component analysis (PCA) was used to identify composite autonomic profiles. <bold>Results</bold> Ninety-eight patients were included (mean age 14.6 ± 5.2 years; 54.1% female). Earlier epilepsy onset was significantly associated with higher resting heart rate and reduced long-range HRV scaling (lower DFA α2), suggesting impaired autonomic maturation. The duration of active epilepsy was significantly associated with a composite HRV profile identified by the PCA analysis (PC1; r = 0.266, p = 0.016), reflecting sympathetic predominance, reduced parasympathetic activity, and altered nonlinear dynamics. <bold>Discussion</bold> Cardiac autonomic regulation appeared to be influenced by the electro-clinical characteristics of epilepsy, mostly dependent on the age at seizure onset and the duration of active epilepsy. The progressive shift toward sympathetic dominance and reduced autonomic complexity warrants to monitor autonomic function in patients with paediatric-onset epilepsies <bold>.</bold> </p>