Concentrations of magnesium, calcium, potassium, and sodium in human heart muscle after acute myocardial infarction.

Atomic absorption spectrometry was used to measure magnesium, calcium, and sodium, and emission spectrometry to measure potassium, in myocardium (left and right ventricles) of 26 control subjects who died of acute trauma. Results were expressed in mumol/g of proteins. Mg/Ca and K/Na ratios were also determined. The same measurements were made in 24 patients who died from acute myocardial infarction. Samples were also taken from the necrotic area. Mg/Ca and K/Na ratios were significantly higher in the left ventricle of both populations, thus providing evidence of anatomical and physiological differences between the two ventricles. As a result of cytolysis and anoxia, the Mg/Ca ratio was very significantly inverted, and the K/Na ratio very significantly smaller, for samples from the necrotic area. In these clinical conditions arrhythmias could certainly be considered likely, and there is reason to believe that magnesium depletion may be a cause of arrhythmias.