Brugada syndrome unmasked by lithium.

A 38-year-old man was brought by emergency medical service after resuscitation following cardiac arrest. The patient was found pulseless with a wide complex tachycardia. The patient had bipolar disorder and was on lithium, lamotrigine, and ziprasidone. His electrolytes and lithium levels were normal. An electrocardiogram (EKG) was performed the next day and showed type 1 Brugada pattern. Lithium was held. Electrophysiologists made a diagnosis of drug-unmasked Brugada syndrome. Lithium can unmask Brugada syndrome through its ability to block sodium channels, even at subtherapeutic concentrations. Physicians need to be aware of this potentially fatal drug effect and should monitor EKGs of patients on lithium.