Lithium overdose with electrocardiogram changes suggesting ischemia

Lithium toxicity is associated with electrocardiogram (ECG) changes, but changes suggestive of an ST segment elevation myocardial infarction have not been reported.

A 46-year-old incarcerated man suffering from diabetes, hypertension, and schizoaffective/bipolar disorder was treated with lithium 1,200 mg twice daily. Two days prior to presentation the patient became confused, ataxic, and anorexic in jail. Lithium level was 4.69 mmol/L. He was transferred to the emergency department. On arrival, vital signs were normal. The ECG showed a normal sinus rhythm. ST segments were elevated in the anterior leads with downward concavity. T waves were biphasic. Since these changes suggested cardiac ischemia and the patient was unable to respond to questions about chest pain, cardiac enzymes and an emergent echocardiogram were done. Troponin I was less than 0.1 microg/L. Echocardiogram was normal, without wall motion abnormalities. Treatment was with hemodialysis and whole-bowel irrigation. Postdialysis lithium level was 1.30 mmol/L. Over the next several days, electrocardiogram normalized. His speech gradually became coherent. After a 1-week hospitalization, he returned to jail.

Lithium intoxication can cause transient ST segment elevations suggesting an acute myocardial infarction. In the absence of a clear history, echocardiogram and cardiac enzymes can be used to rule out a myocardial infarction.