Heart block after intravenous lidocaine in an infant.

A 14-day-old infant received intravenous lidocaine (2 mg X kg-1) at the conclusion of cataract surgery to prevent coughing from tracheal tube stimulation. Within 30 seconds the infant developed high-grade AV heart block and a ventricular rate of 40. Following brief resuscitation efforts, the patient had a normal cardiac rhythm, blood pressure and respiratory pattern. Intravenous lidocaine may be followed by major disturbances in cardiac rhythm and rate. Cautious titration of small doses should decrease the potential for adverse effects.