Cardiac arrhythmias in sudden unexpected death in epilepsy: A systematic review.

Abstract

Aim: Sudden unexpected death in epilepsy (SUDEP) is a rare but devastating event in patients with epilepsy. The role of cardiac arrhythmias is poorly understood. We systematically evaluated the role of cardiac arrhythmias in patients with SUDEP or near-SUDEP from the published literature. Method: A systematic search was performed on PubMed and Embase using terms “cardiac arrhythmias” and “sudden unexpected death in epilepsy”. Case reports/series were included if cardiac monitoring was available and documented during SUDEP/near-SUDEP events. Data collected included baseline demographics, seizure types, baseline and peri-ictal cardiac rhythm, electroencephalograms and respiratory patterns where available. Results: A total of 50 SUDEP and 16 near-SUDEP patients were identified. Epilepsy types were generalised (n=27/66), focal/partial (n=32/66), generalised and focal (n=1/66), and unknown (n=6/66). Amongst generalised tonic-clonic seizures, nearly half (n=13/27) of SUDEP/near-SUDEP occurred at night. Normal sinus rhythm was the most common baseline rhythm (n=29); abnormal baseline rhythms included tachycardia/bradycardia (n=3), first-degree atrioventricular (AV) block (n=2), and QTc prolongation (n=1). During SUDEP/near-SUDEP events, there were 32 documented episodes of asystole (mean onset 6.3±11.5 minutes post-seizure), 7 ventricular fibrillation episodes (mean onset 0.5±0.7 minutes post-seizure), 6 ventricular tachycardia episodes (mean onset 0 minutes post-seizure) and 6 high-degree AV block episodes. The mean onset of apnoeic events post-seizure was 3.8±3.7 minutes. Conclusion: Cardiac arrhythmias observed in SUDEP and near-SUDEP are heterogeneous. The most common mechanism appears to be respiratory apnoea followed by progressive asystole. Further prospective data are needed to clarify this potential mechanism.