Abstract
Background
Seizures commonly affect the heart rate and its variability. The increased interest in this area of research is related to the possible connection with sudden unexpected death in epilepsy (SUDEP). Generalized tonic-clonic seizures (GTCS) are reported as the most consistent risk factor for SUDEP. However, the general risk of seizures (and their type) on cardiac function still remains uncertain.
Purpose
To evaluate the influence of seizure type (GTCS vs non-GTCS) on ictal and early post-ictal Heart Rate Variability (HRV) in patients with refractory epilepsy.
Methods
From January 2015 to July 2018, we prospectively evaluated 121 patients admitted to our institution's Epilepsy Monitoring Unit with focal resistant epilepsy. All patients underwent a 48-hour Holter recording. We included only patients who had both GTCS and non-GTCS during the recording and selected the first seizure of each type to analyze. HRV (AVNN, SDNN, RMSSD, pNN50, and LF/HF) was evaluated by analyzing 5-min-ECG epochs, starting with the seizure onset (ictal and early post-ictal period). The study was approved by our Institution Ethics Committee and all patients gave informed consent.
Results
Fourteen patients were included (7 Females, 4 patients with Temporal Lobe Epilepsy). The median age was 39 years (min-max, 18–57). Thirty-six percent presented cardiovascular risk factors without known cardiac disease.
A significant statistical reduction was found for AVNN (p=0.013), RMSSD (p=0.008), pNN50 (p=0.005) and HF (p=0.003), during GTCS when compared with non-GTCS (Wilcoxon test, p<0.05; two tailed).
Conclusion
Our study shows a significant reduced vagal tone during GTCS when compared with non-GTCS. Hence, GTCS had a more pronounced impact on HRV changes than other seizure types, which can be associated with higher SUDEP risk after GTCS.
Simulated driving in the epilepsy monitoring unit: Effects of seizure type, consciousness, and motor impairment
