The effect of propofol concentration on dispersion of myocardial repolarization in children

Anesth Analg. 2008 Sep;107(3):806-10. doi: 10.1213/ane.0b013e3181815ce3.


Background: QT interval prolongation on the electrocardiogram (ECG) may be drug-induced and is traditionally associated with torsades des pointes. A better predictor of torsades des pointes is the time interval between the peak and the end of the T-wave (Tp-e). Older studies of propofol's effect on the corrected interval (QTc) are conflicting and confounded by polypharmacy. It was recently shown that target-controlled infusion of propofol at 3 microg/mL has no effect on QTc or Tp-e. This plasma concentration of propofol is at the extreme lower end of the range for surgical anesthesia. In this randomized, double-blind, clinical study, we investigated the dose-response relationship between propofol, QTc, and Tp-e in a range of doses clinically relevant for surgical anesthesia.

Methods: Sixty healthy unpremedicated children, aged 3-10 yr, were recruited. Subjects were randomized to receive target-controlled infusions of propofol, to achieve 1 of 3 plasma concentrations: 3, 4.5, and 6 microg/mL. A preoperative 12 lead ECG was performed and repeated 5 min after induction. Two investigators, blinded to group allocation and to the timing of the ECG traces, independently measured QTc and Tp-e within and between each group. Paired t-tests were used to compare QTc and Tp-e within groups. One-way analysis of variance was used for intergroup analysis. The primary outcome measure was a change of >25 ms in Tp-e both within and between groups.

Results: ECG recordings were obtained in 51 children. There were no demographic or ECG differences at baseline, at which time QTc and Tp-e values were within normal limits. There were no differences in QTc or Tp-e after induction within or between the three different groups.

Discussion: Propofol has no effect on myocardial repolarization in healthy children at clinically relevant doses. This suggests that propofol would be a rational choice for children with a preexisting repolarization abnormality.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Anesthesia / methods*
  • Child
  • Child, Preschool
  • Dose-Response Relationship, Drug
  • Double-Blind Method
  • Drug Interactions
  • Electrocardiography / methods*
  • Female
  • Heart / drug effects*
  • Heart Conduction System / drug effects
  • Humans
  • Male
  • Myocardium / metabolism
  • Myocardium / pathology*
  • Propofol / therapeutic use*
  • Torsades de Pointes / metabolism


  • Propofol