Successful uses of magnesium sulfate for torsades de pointes in children with long QT syndrome
Article first published online: 5 APR 2006
Volume 48, Issue 2, pages 112–117, April 2006
How to Cite
HOSHINO, K., OGAWA, K., HISHITANI, T., ISOBE, T. and ETOH, Y. (2006), Successful uses of magnesium sulfate for torsades de pointes in children with long QT syndrome. Pediatrics International, 48: 112–117. doi: 10.1111/j.1442-200X.2006.02177.x
- Issue published online: 5 APR 2006
- Article first published online: 5 APR 2006
- Received 16 September 2004; revised 18 February 2005; accepted 30 June 2005.
- long QT syndrome;
- magnesium concentration;
- torsades de pointes
Background: Administration of magnesium sulfate (MgSO4) is an effective and safe treatment for torsades de pointes (TdP) associated with acquired long QT syndrome (LQTS) in adults. As for children, there are few reports focusing on it. The authors discuss the efficacy of MgSO4 for TdP in children with congenital and acquired LQTS. The authors also discuss the optimal administration dosage and serum magnesium (SMg) concentration during MgSO4 therapy.
Methods: The authors studied seven consecutive LQTS children undergoing MgSO4 therapy for TdP. Of the seven children, five were congenital LQTS and two were acquired LQTS. A bolus injection of MgSO4 was given intravenously over 1–2 min followed by continuous infusion for the next 2–7 days.
Results: Of the seven patients, six responded completely to the initial bolus. The bolus dosage was 5.9 ± 3.8 mg/kg (range, 2.3–12 mg/kg) in these six, and the other remaining one (neonate with congenital LQTS) required a total of 30 mg/kg until complete abolishment. The continuous infusion was given at rates of 0.3–1.0 mg/kg per h and patients did not show recurrence of TdP. The SMg concentration was 3.9 ± 1.0 mg/dL (2.9–5.4 mg/dL) immediately after bolus injection. The mean corrected QT (QTc) interval before and after bolus injection did not show significant difference.
Conclusion: Intravenous infusion of MgSO4 was effective for TdP in children with LQTS, and MgSO4 abolished TdP without shortening the QTc interval. The optimal bolus dosage, infusion rates and SMg concentration were 3–12 mg/kg, 0.5–1.0 mg/kg per h and 3–5 mg/dL, respectively.