Arrhythmia prophylaxis after coronary artery surgery *1A randomised controlled trial of intravenous magnesium chloride

Abstract

One hundred and thirty patients undergoing elective myocardialrevascularisation were randomised to receive an intravenous infusioncontaining either 50 mmol magnesium chloride or placebo during the first 48h following surgery. Magnesium was given to 66 patients and a placeboinfusion to 64 patients. Postoperative serum magnesium concentrations fellin the placebo group (from 0.83 +/- 0.06 to 0.79 +/- 0.11 mmol/l) but wereelevated in the magnesium group (from 0.82 +/- 0.05 to 1.2 +/- 0.25mmol/l). In total, 35 patients (26.9%) had a supraventricular arrhythmia,of which 11 were in the magnesium group (16.7%) and 24 (37.5%) in theplacebo group (P = 0.013). Three patients in the magnesium group had anepisode of ventricular fibrillation and three patients in the placebo grouphad frequent ventricular ectopics. There was one death in the magnesiumgroup associated with a perioperative myocardial infarction. This studyshows that intravenous magnesium supplements reduce the incidence ofsupraventricular arrhythmias following coronary artery surgery.