A Neonate with Long QT Syndrome, Refractory Ventricular Arrhythmias, and Lidocaine Toxicity

Long QT syndrome is characterized by electrocardiographic appearance of long QT intervals and propensity to polymorphic ventricular tachycardia. Aggressive anticipatory clinical management is required for a good outcome, especially in the symptomatic neonate. We present a neonate with a compound mutation with refractory ventricular tachycardia that necessitated multimodal pharmacotherapy with lidocaine, esmolol, and amiodarone along with ventricular pacing. Despite normal serum lidocaine levels, complex pharmacokinetic interactions resulted in presumed neurotoxicity due to lidocaine. This report discusses the implications and challenges of management of a neonate with compound long mutations.