Hypomagnesemia-induced cardiomyopathy.

Magnesium is the fourth most abundant cation in the body and the second most plentiful intracellularly. Magnesium is crucial to mitochondrial integrity, oxidative phosphorylation, protein synthesis, nucleic acid stability, membrane permeability, and neuro-muscular excitability. In addition, magnesium deficiency induces other electrolyte disturbances including hypocalcemia, hypokalemia, and hypophosphatemia. Because it is not routinely measured, many physicians fail to remember the significance of this element. Reported here is a patient with bulimia who presented with a magnesium deficiency which resulted in her refractory and eventually fatal cardiomyopathy. The cardiac pathophysiology of hypomagnesemia, hypokalemia, hypocalcemia and hypophosphatemia is reviewed and correlated with the clinical and pathological findings.