Modification of Tp-e and QTc intervals during caesarean section under spinal anaesthesia

There are no guidelines for the anaesthetic management of caesarean section in women with long QT syndrome; the description of myocardial ventricular repolarisation in healthy women during caesarean delivery could be a first step. The aim of this study was to describe modification of the QT interval, corrected for heart rate, and the interval between the peak and the end of the T-wave (Tpeak-Tend interval) during caesarean section under spinal anaesthesia. We studied 40 patients scheduled for caesarean section under spinal anaesthesia. Patients were randomly assigned to receive either ephedrine or phenylephrine to prevent hypotension. We injected 5 IU oxytocin after delivery. Corrected QT and Tpeak-Tend intervals were unchanged from pre-operative values after induction of spinal anaesthesia, but increased significantly after oxytocin injection. The choice of vasopressor did not affect the Tpeak-Tend interval. The risk-benefit balance of oxytocin bolus during caesarean delivery should be discussed with women with a history of long QT syndrome.