Lithium Therapy with Pacemaker

To the Editor

I found much of interest in the case report by Kähkönen et al. [1] I have encountered a similar case. Although I have reported on our case up to the time when a permanent pacemaker was implanted for sick sinus syndrome induced by lithium therapy [2], it seems worthwhile to report the results of the subsequent 7-year lithium maintenance therapy under permanent pacing.

The patient was a 56-year-old woman with a 37-year history of bipolar disorder. She suffered from syncope and sick sinus syndrome during lithium therapy. This syndrome completely disappeared following lithium discontinuation. Since she relapsed into mania and her manic state did not respond to valproate or carbamazepine, low doses of lithium were resumed. After resumption of lithium, the severe sick sinus syndrome also recurred. At that time, sinus node dysfunction was not alleviated, even after lithium discontinuation. Thus, a permanent pacemaker was implanted.

After that, the patient relapsed into mania and I restarted lithium therapy. For the next 4 years, she was prescribed 600 - 1,000 mg per day of lithium (0.7 - 1.1 mEq/l), 600 - 800 mg per day of carbamazepine (6 - 12 µg/ml), 50 - 100 g per day of levothyroxine, and 2 mg per day of flunitrazepam or 0.25 mg per day of triazolam. During this period, she sometimes suffered from small fluctuations of mood but no clear relapses, and her pacemaker was functioning well. After her pharmacotherapy was established, she changed her outpatient clinic from our university hospital to a private clinic, where she has received similar psychotropic drugs, including lithium, for the last 3 years up to the present. She has remained in good condition regarding both her mental state and cardiac pacing.

In the present case, lithium maintenance therapy has been successfully carried out under permanent pacing for a total of 7 years after pacemaker implantation. As Kähkönen et al. indicated [1], cardiac pacing can maintain sinus rhythm during lithium prophylactic treatment continuation for mood disorder.

References

• 1 Kähkönen S, Kaatinen M, Juhela P. Permanent pacing-aid to carry out long-term lithium therapy in manic patient with symptomatic bradycardia.  Pharmacopsychiatry. 2000;  33 157
• 2 Terao T, Abe H, Abe K. Irreversible sinus node dysfunction induced by resumption of lithium therapy.  Acta Psychiatr Scand. 1996;  93 407-408