Case Report: Lacosamide unmasking SCN5A-associated Brugada syndrome in a young female with epilepsy

Abstract

Background: Lacosamide is frequently used as a mono- or adjunctive therapy for the treatment of adults with epilepsy. Although lacosamide is known to act on both neuronal and cardiac sodium channels, potentially leading to cardiac arrhythmias, including Brugada syndrome (BrS), its adverse effects in individuals with genetic susceptibility are less understood.

Case: We report a 33-year-old female with underlying epilepsy who presented to the emergency department with a four-day history of seizure clusters, and was initially treated with lacosamide therapy. During the intravenous lacosamide infusion, the patient developed sudden cardiac arrest caused by ventricular arrhythmias necessitating resuscitation. Of note, the patient had a family history of sudden cardiac death. Workup including routine laboratory results, 12-lead electrocardiogram (ECG), echocardiogram, and coronary angiogram was non-specific. However, a characteristic type 1 Brugada ECG pattern was identified by ajmaline provocation testing; thus, confirming the diagnosis of BrS. Subsequently, the genotypic diagnosis was confirmed by Sanger sequencing, which revealed a heterozygous mutation (c.2893C>T, p.Arg965Cys) in the SCN5A gene. Eventually, the patient underwent implantable cardioverter-defibrillator implantation and was discharged with full neurological recovery.

Conclusion: This case highlights a rare but lethal adverse event associated with lacosamide treatment in patients with genetic susceptibility. Further research is warranted to investigate the interactions between lacosamide and SCN5A variants.

Keywords: Brugada syndrome; SCN5A; arrhythmia; epilepsy; lacosamide; seizure.

Figure 1

(A) The electrocardiogram of the young female patient showing ventricular fibrillation during resuscitation initially. (B) After achieving recovery of spontaneous circulation, the sinus rhythm soon degenerated into polymorphic ventricular tachycardia again.

Figure 2

(A) A baseline 12-lead ECG of the patient showed a Brugada type 2 pattern (saddleback ST-segment elevation) in the precordial leads V1 placed at 4th ICS and lead V2 placed at 4th ICS. (B) About four minutes after the IV ajmaline injection, a Brugada type 1 pattern (coved-type ST-segment elevation) appeared in all precordial and high intercostal leads (V3-V6). Of note, lead V3 at the right 3rd ICS and lead V4 were placed at the left 3rd ICS, whereas lead V5 at right 2nd ICS and lead V6 were placed at the left 2nd ICS, respectively. ICS, intercostal space.