Effects of antiepileptic drug therapy on heart rate variability in children with epilepsy

Impaired cardiac autonomic function may contribute to the risk of sudden unexpected death in epilepsy. Heart rate variability (HRV) is a useful tool for the detection of sympathetic-parasympathetic balance of autonomic nervous system. In the present study, epilepsy patients who had never received antiepileptic medication and those whose seizures have been successfully controlled with antiepileptic drugs were compared with each other and a control group in order to investigate the effects of epilepsy and various antiepileptic drugs on HRV. HRV were tested via 5 min ECG monitoring in 92 patients and 83 controls. Time domain parameters including SDNN, RMSSD and the frequency domain parameters including HF (reflects parasympathetic activity) and LF (reflects sympathetic activity) were assessed. In this group, 78 patients were using antiepileptic drugs including valproic acid (n=33), oxcarbazepine (n=19), phenobarbital (n=11), combined regimens (n=10) and other drugs (n=5), while 14 patients had never received antiepileptic medication. For both of the epilepsy patients groups with or without treatment, time domain parameters were found to be significantly suppressed. In addition, parasympathetic activity was found to be decreased (HF was decreased, LF/HF ratio was increased) in epilepsy patients without antiepileptic drug therapy. Our results indicate that seizure control with antiepileptic drugs may help to improve the cardiac autonomic function impairment in epilepsy patients.