Effect of magnesium sulfate on cardiac arrhythmias after open heart surgery

Postoperative cardiac arrhythmias are among the most common complications of cardiac surgery. The purpose of this study was to assess the effect of infusion of magnesium-sulfate on the incidence of cardiac arrhythmias especially atrial fibrillation (AF) and premature ventricular contraction (PVC) in patients undergoing on-pump coronary artery bypass grafting (CABG). In this clinical trial 120 patients were randomly divided into two groups. In experimental group sixty patients received intravenous magnesium-sulfate 2gr at the night before operation and 2gr during operation and 30mg/kg on the first, second, third, and fourth days after surgery. In control group sixty patients underwent surgery as the routine treatment. Incidence of atrial fibrillation and premature ventricular contraction were evaluated during and after surgery. For analysis of qualitative variables, X2 and Exact Fischer tests were used. Preoperative patient characteristics and operative variables were similar in both groups (P>0.05). No postoperative AF was detected in the patients of magnesium group, while 4 (8.3%) patients in control group developed AF post-operatively (P=0.03). Post-operative PVC occurred in 12 (20.7%) patients of magnesium group and in 21 (42.9%) patients of control group (P=0.02). Infusion of magnesium sulfate during operation seems to be effective in the prevention of new episodes of AF and PVC after coronary artery bypass grafting (CABG).