Clinical studies on serum magnesium level in cardiac dysfunction with special reference to serum free fatty acid and plasma noradrenaline levels

Impaired magnesium metabolism in congestive heart failure (CHF) or in acute myocardial infarction (AMI) has been postulated as one of the important exacerbating factors for cardiac dysfunction or in dys-arrhythmias. However, the precise mechanism of lowering serum magnesium levels (s-Mg) in these clinical state still remains unclear. We tested the notion that an enhanced endogeneous sympathetic activity might impair the magnesium metabolism through peripheral free fatty acid curate action. Patients with treated congestive heart failure (n=36) and untreated acute myocardial infarction (n=19) were enrolled for this study, and plasma noradrenaline concentration (pNA, HPLC-THI), serum magnesium (s-Mg, atomic spectrometry) and free fatty acid level (FFA, enzymatic method) were examined. Moreover, in normal control subjects (n=12), the changes of s-Mg and FFA were also measured by intravenously administrated noradrenaline (0.1-0.2μg/kg/min,15minutes). Significant differences existed in pNA (586.9±67.7pg/ml,p<0.001) and s-Mg (1.19±0.04mEq/l,p