〈Originals〉The effect of sevoflurane or propofol with or without an anti-emetic dose of droperidol on the QTc interval and the transmural dispersion of repolarization

[Abstract] Purpose : Sevoflurane and droperidol but not propofol induce QTc interval prolongation, but there are several conflicting reports. We investigated the effects of sevoflurane and propofol with or without an anti-emetic dose of droperidol on the QTc interval and the transmural dispersion of repolarization for 2 hours, and the QT interval was adjusted for the patient\u27s heart rate using 3 formulae. Methods : One hundred two American Society of Anesthesiologists (ASA) physical status I-II patients, aged 20-70, were randomly allocated to one of four groups : Group 1 (n＝25) receiving sevoflurane anesthesia without droperidol (1.25 mg), Group 2 (n＝26) receiving sevoflurane anesthesia with droperidol, Group 3 (n＝ 25) receiving propofol anesthesia without droperidol, or Group 4 (n＝26) receiving propofol anesthesia with droperidol. RR intervals, QT intervals, and Tp-e intervals, which indicates the dispersion of ventricular repolarization (TDR), were mea-sured. The QT interval was adjusted for the patient\u27s heart rate using the formulae of Bazett, Fridericia, and Matsunaga. Results : Sevoflurane significantly prolonged the QTc, but droperidol did not enhance sevoflurane- induced QTc prolongation in all the formulae. Conversely, propofol did not affect the QTc in all formulae. Tp-e intervals were not affected in any of the groups. Conclusion : Although it significantly prolongs the QTc interval, sevoflurane, even with droperidol, does not seem to cause lethal arrhythmias associated with QT prolongation, because it does not induce Tp-e prolongation. Propofol is safer than sevoflurane in terms of arrhythmias associated with QT interval prolongation. Bazett\u27s formula is reliable for detecting anesthetic- induced QT prolongation