Abstracts

Rationale: Significant autonomic changes occur during seizures and may be related to sudden unexplained death in epilepsy (SUDEP). Accordingly, we performed a study to determine the prevalence and spectrum of electrocardiographic (including heart rate and QTc) and oximetric changes during seizures in children and adults. Methods: Patients admitted to our Epilepsy Monitoring Units were recruited prospectively to undergo quantitative analysis of ECG and pulse oximetry recordings obtained during seizures. Results: 218 seizures from 76 patients were analyzed. Ictal sinus tachycardia occurred in 76% of patients (57% of seizures) and was associated with normal pre-admission MRI (23/25 with normal imaging versus 34/48 with abnormal imaging, Pearson s chi-square p=0.04), higher number of failed anti-epileptic drugs (6.1 /- 3.0 drugs versus 4.4 /- 2.5 drugs, independent-samples student s t-test 2 tailed p=0.025), and generalized seizures (58/79 generalized versus 66/138 complex partial, Pearson s chi-square p<0.001). Ictal sinus bradycardia occurred in 5.3% of patients (1.8% of seizures) and was associated with current beta blocker use (1/3 on beta blockers versus 3/73 off such medications, Pearson s chi-square p=0.026). Ictal hypoxemia occurred in 35% of patients (25% of seizures) and was associated with longer seizure duration (173 /- 162 seconds versus 101 /- 196 seconds, independent-samples student s t-test 2 tailed p=0.049), ictal tachycardia (17/34 with tachycardia versus 1/16 without, Pearson s chi-square p=0.003), and normal preadmission brain MRI (11/18 with normal imaging versus 7/31 with abnormal imaging, Pearson s chi-square p=0.01). Ictal QT prolongation (QTc >