Int J Angiol 1999; 8(3): 165-170
DOI: 10.1007/BF01616447
Original Articles

© Georg Thieme Verlag KG Stuttgart · New York

Ventricular arrhythmia suppression by magnesium treatment after coronary artery bypass surgery

Hannu Parikka1 , Lauri Toivonen1 , Kalervo Verkkala2 , Antero Järvinen2 , Markku S. Nieminen1
  • 1Division of Cardiology, Department of Medicine, Helsinki University Central Hospital, Helsinki, Finland
  • 2Department of Thoracic and Cardiovascular Surgery, Helsinki University Central Hospital, Helsinki, Finland
This study was supported by a grant from the Finnish Foundation for Cardiovascular Research, Helsinki, Finland
Further Information

Publication History

Publication Date:
24 April 2011 (online)

Abstract

Ventricular arrhythmias occur frequently shortly after coronary artery bypass grafting (CABG), and their occurrence coincides with the postoperative decline in serum magnesium (Mg) levels. To examine if this decline causes ventricular arrhythmias and if their appearance could be reduced by intravenous Mg administration, 140 consecutive CABG patients were randomized to receive 70 mmol of Mg sulphate (N=69) or placebo (N=71) over two days. Serum Mg concentration fell to 0.77 mmol/l in the control group but rose to 1.09 mmol/l in the Mg group (p < 0.001). On 48 h Holter, the number of ventricular premature complexes (VPC) on the third postoperative day was reduced in the Mg group (4 ± 5 vs 12 ± 21 VPCs/h; p < 0.05) and the incidence of complex ventricular arrhythmias (Lown grade 2–5) was significantly diminished (19% vs 41% of the patients; p < 0.05). In multivariate analysis, high risk ventricular arrhythmias (repetitive polymorphic ventricular complexes, couplets, R-on-T complexes or operative tachycardia) were independently predicted by high number of bypassed vessels (p = 0.01), poor NYHA functional class (p = 0.06), preoperative diuretic use (p = 0.07), and low postoperative Mg levels (p = 0.08). In conclusion, correction of the postoperative decline in serum Mg concentration decreases the occurrence of early VPCs and complex ventricular arrhythmias. Patients with extensive underlying coronary artery disease and prior diuretic therapy appear to benefit greatest from Mg treatment.

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