The effect of levobupivacaine and bupivacaine on QT, corrected QT (Qtc), and P wave dispersions in cesarean section

Background and objectives: In our study we aimed to investigate the effect of bupivacaine and levobupivacaine on QT, corrected QT (QTc), and P wave dispersion durations during spinal anesthesia in cesarean section.

Methods: Sixty parturients scheduled for elective cesarean section in ASA I-II risk groups were included in the study. Baseline electrocardiographic (ECG) records of the patients were obtained in the operation room. Heart rate (HR), non-invasive blood pressure (NIBP), peripheral oxygen saturation (SpO2) and respiration rates (RR) were recorded. Venous cannulation was performed with 18G cannula and fluid preload made with 10 mL.kg(-1). Lactated Ringer solution. After fluid preload, second ECG recordings were taken and the patients were randomly separated into two groups. Group B (n = 30) received 10mg of bupivacaine and Group L (n = 30) received 10mg of levobupivacaine for spinal anesthesia. ECG recordings were repeated at 1, 5 and 10 minutes after spinal block. HR, NIBP, SpO2, RR and sensory block levels were also recorded at the same time intervals. At predetermined time intervals of spinal anesthesia, P wave dispersion (Pwd), QT dispersion (QTd), and QTc dispersion (QTcd) durations were measured from ECG records. QT and QTc durations are calculated with Bazzett formula.

Results: There was no difference between two groups according to block levels, hemodynamic parameters, Pwd, QTd, QTc and QTcd durations.

Conclusion: Bupivacaine and levobupivacaine may be preferred in spinal anesthesia in pregnant patients who have extended Pwd and QTcd preoperatively.