Reversing sevoflurane-associated Q-Tc prolongation by changing to propofol

Congenital or acquired forms of the long Q-T syndrome may result in ventricular tachycardia known as torsade de pointes. Many drugs including volatile anaesthetics modify the Q-T interval. Sevoflurane is known to prolong of the rate-corrected Q-T interval (Q-Tc). The objective of this study was to determine whether the sevoflurane-associated Q-Tc prolongation is rapidly reversible when propofol is substituted for sevoflurane. Thirty-two female patients were allocated to two groups. All patients received sevoflurane induction and anaesthesia for 15 min. In one group, sevoflurane was then discontinued and anaesthesia maintained on propofol for another 15 min. The second group received sevoflurane anaesthesia for 30 min. Measurements were taken before, and 15, 20, 25 and 30 min after induction. Q-Tc prolongation was significantly reduced 5, 10 and 15 min after propofol had been substituted for sevoflurane. We conclude that the sevoflurane-associated Q-Tc prolongation is fully reversible within 15 min when propofol is substituted for sevoflurane.