Contribution of continuous intravenous lidocaine in managing congenital long QT syndrome with 2:1 atrioventricular block

Congenital long QT syndrome (LQTS) is a rare hereditary cardiac disorder characterized by prolongation of the QT interval on electrocardiogram (ECG), predisposing affected individuals to life-threatening arrhythmias. We present a case of a newborn with congenital LQTS and 2:1 atrioventricular (AV) block who presented with bradycardia and QT prolongation. Continuous intravenous lidocaine infusion was initiated, because of hypoglycemia with beta-blockers, resulting in stabilization of AV conduction and prevention of malignant arrhythmias. This case underscores the potential utility of lidocaine as an adjunctive therapy in managing refractory arrhythmias in newborns with congenital LQTS and AV conduction abnormalities.