Possible involvement of hypothyroidism as a cause of lithium-induced sinus node dysfunction.
Although several reports have stated that even therapeutic levels of lithium can induce sinus node dysfunction, the mechanism has not been fully elucidated. We present here two patients with sinus node dysfunction after long-term lithium therapy. Following lithium discontinuation, sinus node function recovered completely. After resuming lithium, however, irreversible sinus node dysfunction recurred and a permanent pacemaker was implanted in one patient. The serum concentration of lithium was within therapeutic levels. Nevertheless, hypothyroidism was associated with the sinus node dysfunction in both patients. Thus, thyroid function may play an important role in sinus node dysfunction induced by lithium.
Second Department of Internal Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
T
T
Numata
H
H
Abe
T
T
Terao
Y
Y
Nakashima
D000328:Adult; D018692:Antimanic Agents / Q000008:administration & dosage / Q000009:adverse effects*; D001714:Bipolar Disorder / Q000188:drug therapy*; D004305:Dose-Response Relationship, Drug; D015716:Electrocardiography, Ambulatory / Q000187:drug effects; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000139:chemically induced* / Q000175:diagnosis; D016651:Lithium Carbonate / Q000008:administration & dosage / Q000009:adverse effects*; D008875:Middle Aged; D012804:Sick Sinus Syndrome / Q000139:chemically induced* / Q000175:diagnosis; D013960:Thyroid Function Tests
D018692:Antimanic Agents; D016651:Lithium Carbonate