Lithium Toxicity and Level Dependent Sinoatrial Exit Block

Background: Lithium toxicity has been associated with variable changes on Electrocardiogram (ECG) but several long pauses secondary to Sinoatrial (SA) exit block have not been formally reported. Conclusion: Our case highlights that in chronic lithium patients presenting with altered mental status and conduction problems, an emergency physician should have a high index of suspicion for lithium toxicity and appropriate therapy to be initiated expeditiously. Further experiments on human and animal models involving molecular pharmacology and electrophysiology are necessary to understand the sinus node/perisinus tissue electrophysiological behavior caused by Lithium.