buy cialis viagra The findings demonstrate that 1 measurements of Mg i in sublingual epithelial cells correlate well with those of cardiac cells, 2 Mg i levels in patients undergoing cardiac surgery are lower than levels in control subjects despite normal serum magnesium, 3 subjects presenting with AMI have significantly lower Mg i levels compared with both healthy control subjects and acutely ill patients lacking myocardial ischemia, and 4 administration of intravenous MgSO 4 raises Mg i levels within 24 hours