Sinus Node Dysfunction and Pulmonary Hypertension-"Double Trouble" with Lithium Therapy

Lithium is considered a gold standard drug for the management of bipolar disorder and is a widely used mood-stabilizing drug in psychiatry practice. However, its side effects are of important concern. The narrow therapeutic index of lithium predispose it to toxicity/side effects, but various case reports in literature have shown that adverse drug reactions can occur even in the therapeutic range. We present the case of a 56-year-old woman with no history of cardiac illness presenting with tachycardia-bradycardia syndrome along with moderate pulmonary hypertension. Patient reverted to sinus rhythm after withholding lithium therapy for 1 week while her mean pulmonary artery pressure remained the same at day 10 of drug withdrawal.