Abstracts

Rationale: Assessment of heart rate variability (HRV) via spectral analysis can used to measure the autonomic cardiac function. One can separately measure the sympathetic and parasympathetic components of the spectrum. Reduced HRV has been shown to predict increased mortality and risk of sudden death in CHF, MI, and diabetes. Other studies have shown reduced HRV in temporal lobe epilepsy patients. We previously demonstrated that there were measurable differences in HRV between patient patients with normal and abnormal EEGs utilizing 5 minute epochs. EKG abnormalities are also seen in patients in status epilepticus. We set out to determine if measurable differences in HRV can be seen in patients in Status Epilepticus. Methods: We retrospectively reviewed the autosections of patients monitored under the status protocol in 2006 and 2007. A total of 53 patients were monitored in our adult epilepsy monitoring unit, collecting EEG along with he heart rate data. We reviewed the first autosection of the EKG data. R-R intervals were marked by hand and this data was exported from the software (NicVue) in ASCII format. The R-R intervals were then analyzed using HRV software 1.1 and various time domain and frequency domain measurements were made. Results: Just as we saw in our previous study, there is a statistically significant difference between the two groups in SDNN (p<0.05), which is a time domain measure measure of heart rate variability. In the patients with non-status EEGs, the SDNN is an average of 41.4 ms, while those in status epilepticus are 20.5ms. The decreased SDNN in those patients in status epilepticus is suggestive of decreased heart rate variability. In comparing the ratios of LF (sympathetic) to HF (parasympathetic) between the two groups using normalized units (n.u.), there is a trend of increasing sympathetic activity in the patients with status epilepticus. Conclusions: We were able to confirm that there is statistically significant decreased heart rate variability using time domain measures. There was a trend for increasing sympathetic activity in patient's in status epilepticus, but it was not statistically significant. So we were able to demonstrate there are measurable differences in heart rate variability in patients in status epilepticus utilizing short epochs of time at the beginning of the recording.