it has been recognized for some time that significant cardiac arrhythmias may frequently be seen with epileptic seizure activity1 ) . ictal tachycardia and bradycardia are common arrhythmias , but ictal sinus pause and asystole are rare and more severe . recently , ictal arrhythmia has become a notable warning sign of sudden unexpected death in epilepsy ( sudep ) , which accounts for 15% of all epilepsy - related deaths2 ) . here , a 27-month - old girl was hospitalized due to 5 episodes of convulsions during the past 2 days . the episodes were generalized , febrile or afebrile , and lasted for 30 seconds to 1 minute . in the interictal phase , her mental state was alert , without neurologic deficit . she did not vomit , and had no sign of meningeal irritation on neurologic examination . she had no specific problems in the perinatal period , but she had a history of simple febrile convulsion at 16 months of age . she appeared to be developing proper motor and language skills , without any known disease . all investigations , including blood counts , electrolyte levels , glucose level , chest radiography , echocardiography ( ecg ) , and brain magnetic resonance imaging ( mri ) , were normal . routine sleep electroencephalography ( eeg ) was normal , but she experienced 1 generalized tonic seizure , lasting for 1 minute , every day for 3 days . during 24-hour video - monitored eeg , she showed frequent myoclonic seizures and generalized polyspike discharges with myoclonus followed by sinus pause for > 4 seconds ( asystole ) starting about 5 seconds after myoclonus onset ( fig . one time of sinus pause was noted , which was not accompanied by myoclonus ( fig . twenty - four - hour holter ecg monitoring during the frequent seizure episodes revealed sinus arrhythmia and sinus pauses lasting for 2 to 3 seconds ( fig . the next day , she was initially given valproic acid 20 mg / kg / day . however , 5 days later , she voluntarily stopped taking the anticonvulsant due to a rash on her trunk and back . seven weeks later , she experienced a generalized tonic febrile seizure that lasted for 15 seconds . video - monitored eeg revealed an occasional high - voltage generalized spike and wave or polyspike discharges . twenty - four - hour holter ecg monitoring revealed a sinus block for 1 second , which was not accompanied by clinical seizure . after the valproic acid was restarted , she did not experience any more seizures . in the following 6 months , , she experienced a generalized tonic febrile seizure and myoclonus . at that time , we did not perform eeg or 24-hour holter ecg monitoring . results of an scn1a gene study were normal . at 44 months of age , she maintained the antiepileptic medication and had no seizures , ictal arrhythmias , or developmental delays . our patient experienced frequent myoclonic seizures accompanied by sinus pause lasting for 2 to 3 seconds , resulting in asystole . accidentally an interictal sinus pause was found on the video - monitoring not accompanying by clinical sign . after antiepileptic treatment , there were not any ictal events , interictal epileptiform discharges nor sinus pause on the repeat 24-hour video - monitored eeg and 24-hour holter ecg . seizure - related cardiac arrhythmias are frequently reported in adult : asystole , tachycardia , bradycardia , atrioventricular conduction block , atrial flutter / fibrillation , and ventricular fibrillation . asystole was defined as an relative risk interval of > 3 seconds or > 4 seconds in several reports4 ) . in a recent retrospective study by van der lende et al.4 ) mean prevalence of ictal asystole in all people with refractory focal epilepsy admitted for a video - monitored eeg recording was 0.318% . in a study from rocamora et al.5 ) 5 out of 1,244 patients ( 0.4% ) had 11 asystole events . ictal asystole clinically often presented syncope , cyanosis , loss of consciousness , and subsequent falls . especially in children , three of the 5 patients with ictal asystole had temporal lobe epilepsy , 2 had extratemporal lobe epilepsy , and none had generalized epilepsy . unlike previous reports about ictal asystole in focal epilepsy , this is the first case of a child with myoclonus seizure and asystole recorded on a video eeg and ecg . one recent prospective study reported that ictal apnea and bradycardia occurred more often in children than in adults , whereas ictal tachycardia occurred more often in adults than in children1 ) . in another study , ictal apnea and bradycardia were seen in younger boys with lesions on brain mri , whereas ictal tachypnea and tachycardia were seen in older children and in those without lesions on brain mri7 ) . cardiac arrhythmias have been suggested to play a prominent role in the pathogenesis of sudep in many studies , though the relationship is still unclear78 ) . sudep accounts for as much as 15% to 17% of all epilepsy - related deaths39 ) . sinus pauses and bradycardia mediated by vagal cardiac activation may proceed to cardiac asystole1011 ) . in addition to cardiac arrhythmias , hypoventilation and hypoxia , central apnea , and cerebral shutdown around seizures can contribute to sudden unexpected death12 ) . our patient presented with frequent sinus pauses and did progress to cardiac asystole , but not to sudep . according to van der lende et al.4 ) but there was one severe case of ictal bradycardia and asystole in infant , where the death could not be evitable despite anticonvulsant therapy and pacemaker implantation . in newly diagnosed patients with epilepsy , antiepileptic drug ( aed ) cardiac pace maker implantation should be considered in patients with refractory epilepsy or recurrence of asystole episodes . however , a pacemaker implantation was debated due to possibility of adverse events such as infection and unclear effectiveness on mortality rate . it is important to be alert to the occurrence of ictal arrhythmia and sudep and use a low threshold in cardiac monitoring and investigations . it seems reasonable to assume that the best way to identify the risk factors for sudep , especially occurring in young age and maintain a therapeutic antiepileptic aed level9 ) .
ictal tachycardia and bradycardia are common arrhythmias ; however , ictal sinus pause and asystole are rare . 
 ictal arrhythmia is mostly reported in adults with temporal lobe epilepsy . 
 recently , ictal arrhythmia was recognized as a major warning sign of sudden unexpected death in epilepsy . 
 we present an interesting case of a child with ictal sinus pause and asystole . 
 a 27-month - old girl was hospitalized due to 5 episodes of convulsions during the past 2 days . 
 results of routine electroencephalography ( eeg ) were normal , but she experienced brief generalized tonic seizure for 3 days . during video - monitored eeg and echocardiography ( ecg ) , she showed multiple myoclonic seizures simultaneously or independently , as well as frequent sinus pauses . 
 after treatment with valproic acid , myoclonus and generalized tonic seizures were well controlled and only 2 sinus pauses were seen on 24-hour holter ecg monitoring . 
 sinus dysfunction should be recognized on eeg , and it can sometimes be treated successfully with only antiepileptic medication .