Possible correlation between decrease of ionized magnesium and calcium in blood to patient outcome after acute myocardial infarction

Journal of Clinical and Basic Cardiology 2000; 3 (2): 123-128

PDF    Summary    Figures   




Keywords: akuter Myokardinfarkt,  Kalziumionen,  magnesium,  Magnesiumionen,  acute myocardial infarction,  ionized calcium,  ionized magnesium,  total magnesium

Acute myocardial infarction (MI) can result in severe complications such as ventricular arrhythmia and congestive heart failure. Contributing factors to these complications may be disturbances in the calcium and magnesium status, especially in the biologically active ionized fraction in plasma. The purpose of this prospective study was to evaluate whether changes in ionized magnesium (iMg2+) and ionized calcium (iCa2+) concentrations could predict the outcome after acute myocardial infarction (MI). In a group of 33 MI patients, total and ionized plasma magnesium and calcium were measured within the first four hours after the onset of symptoms. Major adverse cardiac events (MACE) were observed during the entire hospital stay (23±5 days). For the measurement of iMg2+ and iCa2+ an ion-sensitive electrode was used and the total amounts of calcium and magnesium were measured by atomic absorption spectrometry. By logistic regression analysis indicators for developing complications after acute MI were found to be low iCa2+ (<1.1 mmol/l) and a low quotient between iMg2+ and total magnesium (QMg < 0.65; p < 0.05). Low QMg seems to indicate a decrease of iMg2+ in the first hours after an acute MI. When QMg was ³ 0.65, only 5 out of 23 (22 %) patients developed MACE, in contrast to 7 out of 10 patients (70 %) with QMg < 0.65 (p < 0.01). Similar results were found for iCa2+: 5 out of 22 patients with iCa 2+ ³ 1.1 developed MACE in contrast to 7 out of 11 patients with iCa2+ < 1.1 mmol/l (p < 0.05). A low quotient between ionized and total magnesium and/or low iCa2+ in blood plasma are correlated to MACE after acute MI. Low iCa2+ seems to be a risk factor for congestive heart failure while low QMg seems to indicate an increased risk of both congestive heart failure and arrhythmia after acute MI. J Clin Basic Cardiol 2000; 3: 123-7.