The effects of volatile induction and maintenance of anesthesia and selective spinal anesthesia on QT interval, QT dispersion, and arrhythmia incidence

OBJECTIVE: The effects of sevoflurane general anesthesia and bupivacaine selective spinal anesthesia on QT dispersion (QTd) and corrected QT (QTc) interval were investigated. METHODS AND MATERIALS: This prospective, randomized, double-blind study was conducted between July and September 2009 in the Urology and General Surgery operating rooms. Forty ASA I-II patients undergoing noncardiac surgery were randomized into two groups: Group R (n=20) and Group V (n=20). In Group R, 5 mg bupivacaine was administered into the spinal space. Anesthesia induction in Group V was established with sevoflurane + 0.1 mg/kg vecuronium using the maximum vital capacity technique. Anesthesia was maintained with 2-3% sevoflurane + 50% N2O/O2 inhalation. All patients were tested with a 24-hour Holter ECG device. QT, QTc, and QTd intervals were measured using 12-lead ECG records at 1 and 3 minutes during preinduction, postinduction, postincision and postextubation periods. Mean arterial pressure (MAP), heart rate and ECG records were measured simultaneously. RESULTS: None of the patients displayed arrhythmia. There was no significant difference between the groups with regard to QTd values (p>0.05). However, QTc was longer in Group V than in Group R after the induction of anesthesia at 3 minutes, after the intubation at 1 and 3 minutes, and after the incision at 1 and 3 minutes. MAP and heart rate were generally higher in Group V (