title: Effects of High-Dose Rocuronium on the QTc Interval During Anaesthesia Induction in Patients Undergoing Coronary Artery Bypass Graft Surgery.
abstract: OBJECTIVE
  Existing myocardial damage in coronary artery disease patients causes prolonged QT syndrome. The primary objective of this trial is to explore the effects of different doses of the muscle relaxant agent rocuronium (0.6 mg kg(-1) and 1.2 mg kg(-1)) on QTc following anaesthetic induction. The second objective is to determine the incidence and kinds of arrhythmias.
  
  
  METHODS
  In this prospective and randomized trial, patients undergoing elective coronary artery revascularization surgery were included in one of two groups. Both groups took the same anaesthetic induction agents: midazolam and fentanyl. Rocuronium was administered in Group 1 (n=20) with dose of 0.6 mg kg(-1) and in Group 2 (n=20) with a dose of 1.2 mg kg(-1) for muscle relaxation. Heart rate, average arterial pressure and QTc were recorded before induction (T0), after induction (T1), after muscle relaxant (T2), and 2 minutes (T3) and 5 minutes after intubation (T4).
  
  
  RESULTS
  QTc was significantly longer 2 minutes after intubation (in Group 1 and Group 2, respectively, 447.9±28.3 and 466.1±37.8 ms) than at the beginning (respectively, 426.9±25.7, 432.0±35.5 ms) (p<0.01). In the intergroup comparison, average QTc values were similar in all trial periods (p>0.05). The prevalence of arrhythmias in between Group 1 (35%, n=7) and Group 2 (15%, n=3) was similar (p=0.06). Arrhythmias were recorded 2 minutes after intubation in both groups (n=10, 25%).
  
  
  CONCLUSIONS
  In patients undergoing coronary artery revascularization surgery, rocuronium doses of 0.6 mg kg(-1) and 1.2 mg kg(-1) prolong the QTc interval after intubation. Cardiac arrhythmias related to long QTc arising after intubation should be taken into consideration.
authors.affiliation: Clinic of Anaesthesiology, Van İpekyolu State Hospital, Van, Turkey.
authors.forename: Doğuş
authors.initials: D
authors.lastname: Ağdanlı
authors.affiliation: Department of Anaesthesiology and Reanimation, Celal Bayar University Faculty of Medicine, Manisa, Turkey.
authors.forename: Tülün
authors.initials: T
authors.lastname: Öztürk
authors.affiliation: Clinic of Cardiology, Grandmedical Hospital, Manisa, Turkey.
authors.forename: Ozan
authors.initials: O
authors.lastname: Ütük
authors.affiliation: Department of Anaesthesiology and Reanimation, Celal Bayar University Faculty of Medicine, Manisa, Turkey.
authors.forename: Gönül Tezcan
authors.initials: GT
authors.lastname: Keleş
keywords: QTc; Rocuronium; coronary artery disease