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

Congenital or acquired forms of the long Q-T syndrome may result in ventric ular tachycardia known as torsade de pointes. Many drugs including volatile anaesthetics modify the Q-T interval. Sevoflurane is known to prolong of t he rate-corrected Q-T interval (Q-Tc). The objective of this study was to d etermine whether the sevoflurane-associated Q-Tc prolongation is rapidly re versible when propofol is substituted for sevoflurane. Thirty-two female pa tients were allocated to two groups. AU patients received sevoflurane induc tion and anaesthesia for 15 min. In one group, sevoflurane was then discont inued 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 s ignificantly reduced 5, 10 and 15 min after propofol had been substituted f or sevoflurane. We conclude that the sevoflurane-associated Q-Tc prolongati on is fully reversible within 15 min when propofol is substituted for sevof lurane.