Lidocaine toxicity in the setting of HeartMate II left ventricular assist device

WHAT IS KNOWN AND OBJECTIVE: Lidocaine infused at 1-4 mg/min is an appropriate treatment modality for hemodynamically stable ventricular tachycardia (VT) with normal hepatic function. A case of acute lidocaine toxicity in the setting of left ventricular assist device (LVAD) is reported. CASE SUMMARY: A 71-year-old with a HeartMate II LVAD on chronic mexiletine and normal liver function presented with ventricular tachycardia requiring systemic lidocaine and subsequently developed altered mental status with tremors. A lidocaine level obtained within 24 hours of infusion initiation was 7.9 mcg/mL. WHAT IS NEW AND CONCLUSION: This case highlights the potential for marked deviation from published pharmacokinetic parameters for a narrow therapeutic window agent with concurrent LVAD.