The analysis of circadian rhythm of heart rate variability in patients with drug-resistant epilepsy

The significant suppression of HRV parameters in patients with refractory epilepsy may reflect the inhibitions of both sympathetic and parasympathetic activities. This is notably the first time that marked circadian diversity of HRV measurments between the patient and control groups were found and quantified by cosinor fit method. The difference in amplitude increased during night with peak occurrence between 5:00 or 6:00 a.m. These findings may be linked to cardiac autonomic dysfunction and subsequent sudden unexpected death in epilepsy (SUDEP), which is reported to often occur during night or early morning. Taken together, HRV parameters may be potential bio-markers for predicting SUDEP.