Tehran University of Medical Sciences Journal of Sleep Sciences 2476-2938 1 2 2016 07 27 38 43 EN Zohreh Edalatyzadeh Department of Physiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran Alireza Imani Department of Physiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran Mahdieh Faghihi Department of Physiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran Samira Choopani Department of Physiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran Sahar Askari Department of Physiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran Marjan Aghajani Department of Physiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran Khosro Sadeghniiat-Haghighi Occupational Sleep Research Center, Baharloo Hospital, Tehran University of Medical Sciences, Tehran, Iran 2016 06 17 Background and Objective: Sleep deprivation (SD) is caused by a host of reasons and has numerous consequences on cardiac system. In this study, we aimed to assess the preconditioning effects of acute SD on ischemia (IS)-induced ventricular arrhythmias in isolated rat hearts. Materials and Methods: Male Wistar rats randomly were placed into the four groups: IS-group, acute SD group, control group for SD, and sympathectomy group (SYM). SD paradigm in SD was performed 24 hours before IS induction. In SYM groups, the animals were chemically sympathectomized 24 hours before SD. The rat hearts were isolated and perfused with Krebs buffer solution by Langendorff method and subjected to 30 minutes regional IS. Throughout the experiment, the hearts were allowed to beat spontaneously; thereafter, heart rate (HR) and ventricular arrhythmias were measured. Results: No differences were found between the experimental groups for HR at baseline and IS period. As compared to IS group, SD animals showed less incidence of ventricular tachycardia and severity of arrhythmias (P < 0.050). Furthermore, significantly the number of ventricular ectopic beats episodes/min, bigeminy/min,trigeminy/min, and couple/min were less than IS group (P < 0.050). Moreover,  sympathectomy could reverse results to IS group level as compared to sleep deprived animals (P < 0.050). Conclusion: It is concluded that induction of acute SD before IS could reduce ventricular arrhythmias, and chemical sympathectomy removed this cardioprotection. https://jss.tums.ac.ir/index.php/jss/article/view/27 https://jss.tums.ac.ir/index.php/jss/article/download/27/23