# Hypomagnesemia: An Overlooked Cause of Delirium and Cardiac Complications in an Elderly Patient

## TL;DR

An elderly patient's delirium and heart issues were caused by low magnesium, showing the importance of checking magnesium levels in similar cases.

## Contribution

This case highlights hypomagnesemia as a reversible cause of delirium and cardiac complications in elderly patients.

## Key findings

- Severe hypomagnesemia was linked to delirium, ST-segment depression, and elevated troponin in an elderly patient.
- Intravenous magnesium treatment rapidly resolved neurological and cardiac symptoms.
- Electrolyte imbalances, particularly magnesium deficiency, should be routinely assessed in elderly patients with delirium.

## Abstract

Delirium is a frequent complication in elderly patients and is often multifactorial, with electrolyte imbalances representing a major contributor. While sodium, potassium, and calcium disorders are commonly evaluated, hypomagnesemia is an overlooked but clinically significant cause of both neurological and cardiac manifestations. Magnesium is essential for neuronal stability, neurotransmitter regulation, and calcium channel modulation. Its deficiency can lead to neuropsychiatric symptoms, arrhythmias, and myocardial injury. We report the case of an 81-year-old woman who presented with acute confusion following several days of diarrhea. Investigations revealed severe hypomagnesemia (serum magnesium: 0.3 mmol/L), ST-segment depression, prolonged QT interval, and elevated troponin levels. She was managed as a type 2 myocardial infarction in the context of sepsis and electrolyte imbalance. Prompt intravenous magnesium replacement resulted in rapid resolution of delirium and cognitive improvement. This case underscores the importance of routine assessment of magnesium levels in elderly patients presenting with delirium, especially in the presence of gastrointestinal losses or cardiovascular comorbidities, and highlights the reversibility of neurological and cardiac complications when deficiency is corrected.