Lithium-induced sinus node dysfunction.

A 74-year-old woman, on lithium carbonate treatment, developed symptomatic sinus node dysfunction and central nervous toxicity, which disappeared after discontinuation of the drug and when serum lithium fell from 2 to 1.27 mEq/L. Our review of the literature demonstrates that sinus node abnormalities can occur both in presence of therapeutic and toxic serum lithium levels and are frequently asymptomatic and completely reversible. All patients receiving lithium should have their pulse regularly recorded and the drug should be promptly discontinued if severe bradycardia or other rhythm disturbances appeared during the treatment.