BS10. Asystole in the video-telemetry unit-two cases

Abstract

Primary asystole occurs when the cardiac purkinje fibers intrinsically fail to generate a ventricular depolarization. This is preceded by a bradyarrhythmia due to complete heart block, sick sinus syndrome, or both. Ictal asystole occurs due to synchronization of cardiac autonomic neural discharges with ictal epileptiform activity. Both types of asystole can cause similar events with loss of consciousness and collapse, and are important to differentiate from one another. Ictal asystole has been reported in as many as 0.4% of video-EEG monitored patients (Scheule et al., 2007), and is more common in temporal lobe epilepsies, where ictal bradycardia can evolve into asystole. In patients with intractable focal epilepsy, in whom a loop recorder had been placed, the incidence of significant bradycardia or asystole has been found to be much higher (up to 21% of these individuals) then previously suspected (Rugg-Gunn et al., 2004). We report the video-electrographic, clinical, and semiological features of two cases who were seen at our institution for diagnostic evaluation. The first individual was 43 year-old lady with a 33-year history of recurrent events. The events were characterised by speech arrest, staring ahead, and subjective visual disturbance, and sometimes by sudden collapse without any focal features or tonic/clonic movements. The second patient was a 35-year old man who presented with recurrent episodes of ringing in his ears, and a feeling of derealisation, with confusion afterward. The same events would frequently evolve with collapse, and/or generalised tonic-clonic movements. Both patients had asystole noted during a period of video-telemetry, one with asystole associated with a focal EEG seizure, and one with primary asystole with no ictal EEG change. We present the clinical and EEG findings in both patients. We will discuss relevant clinical features and semiology that can alert the treating clinician to the need for cardiac monitoring and video-EEG telemetry in order to discern attacks of cardiac from those of ictal origin.