Refractory Ventricular Tachycardia and Seizures With Lacosamide Overdose

Abstract

We describe a 60-year-old female patient who suffered an apparently intentional overdose of lacosamide and who developed status epilepticus secondary to its toxicity, complicated by refractory ventricular arrhythmia necessitating advanced cardiac life support and percutaneous stellate ganglion blockade. Extracorporeal membrane oxygenation was considered, and arterial and venous small-bore sheaths were placed in order to allow for extracorporeal cardiopulmonary resuscitation if cardiac arrest recurred, but they were not ultimately used. She suffered an embolic left middle cerebral artery stroke but otherwise recovered from the episode. This eventful clinical course highlights the dangers of lacosamide in high doses.

Keywords: cardiac arrest; eeg; lacosamide; overdose; seizure; stellate ganglion block; ventricular tachycardia.

Figure 1. Time course

This timeline summarizes the patient’s hospital course starting at status epilepticus, which developed shortly after admission as evidenced by the deterioration of her examination and EEG findings, through her recovery and transfer to general care. CPR - cardiopulmonary resuscitation, VT - ventricular tachycardia, A/V - arterial and venous, L MCA - left middle cerebral artery, TTE - transthoracic echocardiogram, Afib - atrial fibrillation, VTach - ventricular tachycardia heartbeat, ECMO - extracorporeal membrane oxygenation, ROSC - return of spontaneous circulation

Figure 2. Cardiac arrest

Wide complex rapid ventricular tachycardia, which rapidly leads to cardiac arrest. The ventricular tachycardia cycle length was approximately 400 ms with a rate of approximately 260-280 bpm.

Figure 3. Right stellate ganglion block

Ultrasound view of percutaneous blockade of the right stellate ganglion. Bilateral blocks were performed during the resuscitation. The C6 vertebral body likely lies deep (below) the visualized region on this ultrasound image frame. The injection is targeted slightly medial to lateral, beneath the carotid artery, and then lidocaine is injected to visualize the separation of the muscular and fascial layers to confirm correct placement. A bilateral blockade was performed. SCM - sternocleidomastoid muscle, IJ - internal jugular vein, CS - clavicular shadow, CA - carotid artery, SG - stellate ganglion, TH - thyroid tissue, LC - longus colli muscle.