Efficacy of magnesium supplementation to prevent junctional ectopic tachycardia in infant patients after surgery for congenital heart disease / 中国小儿急救医学

ABSTRACT

Objective To approach the efficacy of magnesium sulfate(MgSO4 )supplemantation to prevent junctional ectopic tachycardia(JET)during the early postoperative period in infant patients after sur-gery for congenital heart disease.Methods A total of 325 infant patients undergoing cardiac surgery with cardiopulmonary bypass were randomly divided into two groupsthe trial group (n =162,50 mg /kg 25%MgSO4 )and the placebo group(n =163,normal saline).The serum magnesium concentrations were meas-ured at five time points.Continuous electrocardiographic documentation by Holter monitor was performed for 24 hours after cardiac sugery.Results At T3 time point(1 hour after 50 mg /kg 25% magnesium sulfate and equivalent saline applied in intravenous infusion),the concentration of serum magnesium in trial group was higher than that of the placebo group[(1.79 ±0.33)mmol /L vs.(0.92 ±0.18)mmol /L],and the differ-ence between two groups was significant(P =0.001 ).At T4 and T5 time points(after magnesium sulfate and equivalent saline applied 12 and 24 hours respectively),the concentrations of serum magnesium in trial group were throughout higher than those of the placebo group [T4(1.24 ±0.2)mmol /L vs.(0.83 ±0.17 ) mmol /L;T5(1.20 ±0.16)vs.(0.80 ±0.19)mmol /L,P =0.024,P =0.035,respectively].The overall incidence of JET was 5.2%(17 /325),the placebo group had a significantly greater occurrence of JET than that of the trial group,the difference was significant between two groups [9.2%(15 /163 )vs.1.2%(2 /162),P =0.013 ].The onset time of JET in placebo group was earlier than that of the trial group (P =0.019).A total of 14 of 17 cases(82.4%)with JET had hypomagnesaemia,the cases with JET had a signif-icant longer period of mechanical ventilation and CICU stay.Conclusion Positively supplementation with magnesium sulfate during the early postoperative period in infant patients after surgery for congenital heart diseaae could reduce the incidence of JET.Hypomagnesaemia is related to JET.