De novo ADGRV1 variant in a patient with ictal asystole provides novel clues for increased risk of SUDEP.

Background: Various cardiac and autonomic manifestations are frequently reported during seizures. Among the seizure-related arrhythmia, ictal tachycardia is the most common, followed by ictal bradycardia, with ictal asystole being the rarest. The occurrence of ictal asystole may obscure the clinical presentation and delay the diagnosis, representing a life-threatening presentation of epilepsy, with an elevated risk of sudden unexpected death in epilepsy patients (SUDEP). These cardiac abnormalities are being increasingly recognized as the key to elucidating the mechanisms of SUDEP.

Case presentation: We present a 35-year-old man with a history of focal-onset seizures with impaired consciousness since his mid-20 s. He developed different types of seizures for 2 years, described as tonic seizure and atonic seizure (drop attack). During such clinical events, he suffered from falls and cardiac arrest. However, thorough cardiac electrophysiology and imaging workup failed to reveal a cardiac etiology. Subsequent video electroencephalograph (EEG) monitoring was performed, and ictal bradycardia and ictal asystole were discovered. A cardiac pacemaker was implanted, and at 3-year follow-up, the patient did not suffer more atonic seizures, or falls. Genetic tests discovered a de novo variant of Adhesion G Protein-Coupled Receptor V1 (ADGRV1), which may provide a clue for the patient's ictal asystole and the increased risk of SUDEP.

Conclusions: Considering the important impact of ictal bradycardia and asystole on the morbidity and potential mortality of epileptic patients, it is important to simultaneously utilize EEG and electrocardiogram to confirm the diagnosis. This case report highlights the link between the de novo variant of ADGRV1 and the ictal bradycardia/asystole phenotype and implicates the importance of genetic testing in adult epilepsy patients.