Ictal asystole and ictal syncope: insights into clinical management

Ictal asystole is a rare, serious, and often treatable cause of syncope. There are currently limited data to guide management. Characterization of ictal syncope predictors may aid in the selection of high-risk patients for treatments such as pacemakers.

We searched our epilepsy monitoring unit database from October 2003 to July 2013 for all patients with ictal asystole events. Clinical, electroencephalogram, and ECG data for each of their seizures were examined for their relationships with ictal syncope events. In 10 patients with ictal asystole, we observed 76 clinical seizures with 26 ictal asystole episodes, 15 of which led to syncope. No seizure with asystole duration≤6 s led to syncope, whereas 94% (15/16) of seizures with asystole duration>6 s led to syncope (P=0.02). During ictal asystole events, 4 patients had left temporal seizure onset, 4 patients had right temporal seizure onset, and 2 patients had both. Syncope was more common with left temporal (40%) than with right temporal seizures (10%; P=0.002). Treatment options included antiepileptic drug changes, epilepsy surgery, and pacemaker implantation. Eight patients received pacemakers. During follow-up of 72±95 months, all patients remained syncope free.

Ictal asystole>6 s is strongly associated with ictal syncope. Ictal syncope is more common in left than in right temporal seizures. A permanent pacemaker should be considered in patients with ictal syncope if they are not considered good candidates for epilepsy surgery.