title: Comparison of thiopental and ketamine+xylazine anesthesia in ischemia/reperfusion-induced arrhythmias in rats.
abstract: OBJECTIVE
  To investigate the influence of thiopental (85 mg/kg, intraperitoneally (ip)), and ketamine+xylazine (ketamine 75 mg/kg and xylazine 8 mg/kg, ip) anesthesia on the incidence and duration of ischemia/reperfusion-induced arrhythmias.
  
  
  METHODS
  Myocardial ischemia was induced by a 6-min ligation of the left anterior descending coronary artery, followed by a 6-min reperfusion. Measurements were taken of the incidence and duration of ventricular arrhythmias, the mean arterial blood pressure and heart rate, and the pressure rate-product (as an.index of myocardial oxygen consumption).
  
  
  RESULTS
  The arrhythmia score and the incidence of ventricular fibrillation and tachycardia were significantly decreased in the ketamine+xylazine-anesthetized rats compared with the thiopental-anesthetized group (arrhythmia score: 2.0 ± 2.1 versus 3.7 ± 1.2, P < 0.05). The heart rate was significantly lower in the ketamine+xylazine group during the entire experiment, whilst the pressure-rate product was also significantly lower in the ketamine+xylazine group at different time points of the ischemia and reperfusion periods.
  
  
  CONCLUSIONS
  Ketamine+xylazine anesthesia has a strong antiarrhythmic effect and an apparent depressive action on the heart rate and the myocardial oxygen consumption index. Therefore, ketamine+xylazine anesthesia is not appropriate for the evaluation of possible antiarrhythmic agents. Thiopental anesthesia is preferable to ketamine+xylazine anesthesia in the in vivo ischemia-reperfusion arrhythmia model.
authors.forename: Ersöz
authors.initials: E
authors.lastname: Gonca
mesh_terms: D019162:Anesthetics, Combined / Q000494:pharmacology*; D018686:Anesthetics, Intravenous / Q000494:pharmacology; D000818:Animals; D001145:Arrhythmias, Cardiac / Q000209:etiology / Q000517:prevention & control*; D001794:Blood Pressure / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D007649:Ketamine / Q000494:pharmacology*; D015428:Myocardial Reperfusion Injury / Q000150:complications; D010101:Oxygen Consumption / Q000187:drug effects; D017208:Rats, Wistar; D013874:Thiopental / Q000494:pharmacology*; D014991:Xylazine / Q000494:pharmacology*
chemical_list: D019162:Anesthetics, Combined; D018686:Anesthetics, Intravenous; D014991:Xylazine; D007649:Ketamine; D013874:Thiopental