Severe hypomagnesemia has been implicated as a cause of sudden cardiac death. While it may be suspected, proving it can be difficult.

Diagnosis of sudden cardiac death due to hypomagnesemia involves:

(1) documentation of a potential fatal cardiac arrhythmia on ECG such as ventricular tachycardia or ventricular fibrillation

(2) documentation of low serum magnesium concentrations

(3) exclusion of other causes of sudden death


Confidence in the diagnosis would be increased if the patient is in a high-risk group such as:

(1) hemodialysis

(2) massive transfusion recipient

(3) malnutrition or demonstrated deficient magnesium intake


Documentation of the hypomagnesemia should be performed on an initial blood sample prior to any therapy. Post-mortem analysis of vitreous fluid may be helpful but must be interpreted with caution. Measurement of myocardial magnesium can be performed but may not be readily available.

To read more or access our algorithms and calculators, please log in or register.