Alterations of electrolytes in serum and erythrocytes after myocardial infarction.

Electrolyte concentrations in serum and erythrocytes of 56 myocardial infarction (MI) patients and 50 patients having had an orthopedic operation or an accident were measured up to 2 weeks after the event. Several hours after the MI, considerable percentages of patients had had pathologically low serum concentrations of either K, Ca or Mg. In the erythrocytes of the Mi group, K was decreased and Ca increased during the entire period of investigation, whereas the serum electrolytes K and Ca had normalized by day 15, at which time only half of the patients with pathologically low serum Mg had reached the normal Mg range. By correlation analysis it was shown that the more the Ca concentration in the serum was decreased after MI, the less was the concentration of brain muscle creatine kinase.