Lithium overdose with electrocardiogram changes suggesting ischemia.

BACKGROUND

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

CASE REPORT

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.

CONCLUSION

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.