Case report of antiseizure medicine-induced long QT syndrome and a literature review

Abstract

BackgroundTo realize the clinical characteristics of long QT syndrome (LQTS) caused by antiseizure medicines (ASMs), and to improve the prevention and management of ASM-acquired QT syndrome.Case presentationA case of ASM-acquired QT syndrome was diagnosed and relevant literature was reviewed. The case was a 7-year-old boy who presented with a sudden onset of panic followed by changes in consciousness, with or without convulsions, lasting from tens of seconds to 3 min. The patient then received antiepileptic treatment with valproic acid, levetiracetam and oxcarbazepine and was seizure free for about a year. However, on August 12, 2021, his illness flared up again. Electroencephalogram (EEG) showed the background activity was slow, and no obvious epileptic discharge was detected. But electrocardiogram (ECG) showed a surprisingly prolonged QT interval (770 ms). Torsades de Pointes was found during Holter monitoring, while electrolyte levels were normal. The ECG recordings gradually returned to normal after stopping ASMs. For literature search, only 21 related papers were obtained after reading titles and full-texts of 105 English-language papers retrieved using keywords "acquired QT interstitial syndrome/acquired Long QT Syndrome (aLQTS)" and "anti-epileptic seizure drugs/ASMs", in the databases of Wanfang, CNKI, Pubmed, and other databases, from publication year 1965 to October 26, 2021. There are 12 types of drug-acquired LQTS caused by ASMs, most of which are Na+ blockers, but LQTS caused by oxcarbazepine had not been reported previously.ConclusionsASMs such as oxcarbazepine can cause acquired LQTS. When Na+ or K+ channel blockers are used clinically, ECG should be reviewed regularly and abnormal ECG should be intervened in time to reduce iatrogenic accidents in patients with epilepsy.