Persistent Biventricular Cardiac Dysfunction Following a Large, Acute Metformin Overdose

Metabolic acidosis and hyperlactatemia are known complications of acute metformin toxicity. However, acute cardiac complications are less well described. A 13-year-old female presented following a 150-g metformin ingestion. She developed severe metabolic acidosis, hyperlactatemia, and acute kidney injury requiring intubation and continuous renal replacement therapy. Despite rapid correction of her metabolic disturbances, she developed biventricular cardiac dysfunction requiring vasopressors and milrinone. By hospital day 8, she was extubated and off all vasopressors and inotropes. One week later, her echocardiogram demonstrated normalization of biventricular function. End organ dysfunction associated with acute metformin ingestion is often attributed to severe acidosis. However, despite rapid correction in our patient’s metabolic acidosis, she developed biventricular cardiac dysfunction. Thus, acute, reversible cardiotoxicity should be recognized as a potential complication with large, acute metformin ingestions.