Serum, red blood cell and whole blood magnesium in patients with uncomplicated acute myocardial infarction.

Serum, whole blood and red blood (intracellular) magnesium determinations were made in 52 patients, without other factors predisposing to hypomagnesemia, admitted to a coronary care unit. Acute uncomplicated myocardial infarction was documented in 31 and the serum cardiac enzymes as well as the electrocardiogram remained nondiagnostic in 21 patients. There was no significant difference in the serum magnesium level in the two groups. An increasing trend with time was noted in the serum (p less than 0.001) and whole blood magnesium (p less than 0.005) during the first 4 days postmyocardial infarction. The whole blood magnesium as well as the red blood (intracellular) magnesium was higher (p less than 0.01) in myocardial infarction patients. There was no significant difference in the hematocrit or other electrolytes during this time.