Cardiac Asystole in Epilepsy: Clinical and Neurophysiologic Features

Abstract

Summary: Purpose: Cardiac asystole provoked by epileptic seizures is a rare but important complication in epilepsy and is supposed to be relevant to the pathogenesis of sudden unexplained death in epilepsy (SUDEP). We sought to determine the frequency of this complication in a population of patients with medically intractable epilepsy and to analyze the correlation between EEG, electrocardiogram (ECG), and clinical features obtained from long‐term video‐EEG monitoring.Methods: Retrospective analysis of the clinical records of hospitalized patients from May 1992 to June 2001 who underwent long‐term video‐/EEG monitoring.Results: Of a total of 1,244 patients, five patients had cardiac asystole in the course of ictal events. In these patients, 11 asystolic events, between 4 and 60 s long in a total of 19 seizures, were registered. All seizures had a focal origin with simple partial seizures (n = 13), complex partial seizures (n = 4), and secondarily generalized seizures (n = 2). One patient showed the longest asystole ever reported (60 s) because of a seizure. Cardiac asystole occurred in two patients with left‐sided temporal lobe epilepsy (TLE) and in three patients with frontal lobe epilepsy (FLE; two left‐sided, one bifrontal). Two patients reported previous cardiac disease, but only one had a pathologic ECG by the time of admission. Two patients had a simultaneous central ictal apnea during the asystole. None of the patients had ongoing deficits due to the asystole.Conclusions: These findings confirm that seizure‐induced asystole is a rare complication. The event appeared only in focal epilepsies (frontal and temporal) with a lateralization to the left side. A newly diagnosed or known cardiac disorder could be a risk factor for ictal asystole. Abnormally long postictal periods with altered consciousness might point to reduced cerebral perfusion during the event because of ictal asystole. Central ictal apnea could be a frequent associated phenomenon.

Clinical cues for detecting ictal asystole

“…One might predict that pallor would be more common in ictal syncope than in other seizures, but this could not be determined in our study. It has been suggested that prolonged post-ictal confusion might be a clue to the diagnosis of ictal bradycardia [17]. However, the post-ictal recovery period in ictal asystole and non-asystolic seizures was not significantly different in our series.…”

Cardiac arrhythmias during or after epileptic seizures

“…5 6 The mean prevalence of ictal asystole in all people with refractory focal epilepsy admitted for a vEEG recording was 0.318% (95% CI 0.316% to 0.320%). [7][8][9][10][11] Ictal asystole was only reported in people with focal epilepsy (table 1). Most of the ictal asystoles occurred during the course of a focal dyscognitive seizure (formally known as a complex partial seizure), on average starting 30 s after seizure onset.…”

Ictal Asystole in Focal Epilepsy

“…6 Ictal bradyarrhythmias have been postulated to be secondary to vagal cardiac activation. 7 However, it is not clear whether bradyarrhythmias are from vagal-mediated activation of cardiac function or uncoordinated autonomic effect. 7,8 Prior case reports have demonstrated that ictal bradyarrhythmias begin between 5 and 20 seconds after ictal discharge in partial seizures and 60 and 100 seconds in generalized seizures.…”