chronic sleep deprevation and ventricular arrhythmias: effect of symphatic nervous system

Background: chronic sleep deprivation through activation of sympathetic nervous system leads to destructive effect on different body organs. we assessed the effect of chronic sleep deprivation on incidence of ischemia/reperfusion-induced ventricular arrhythmias (ventricular tachycardia and ventricular fibrillation) and the role of the sympathetic nervous system in this respect. materials and methods: a total of 24 rats were randomly divided into four groups of six; 1) ischemia/reperfusion group (ir): 30 minutes ischemia followed by 60 minutes reperfusion was induced, 2) control group (con): rats has been placed in large multiple platforms for 72h prior to ischemia and reperfusion, 3) chronic sleep deprivation group (sd): 72h sleep deprivation was induced by using small multiple platform prior to ischemia and reperfusion, 4) sympathectomy group (sym): chemical sympathectomy was done 24h before to chronic sleep deprivation and then underwent ischemia and reperfusion. the heart isolated and perfused by langendorff apparatus. after thoracotomy and aorta cannulation, the hearts perfused in the langendorff apparatus using krebs-henseleit buffer. hearts were allowed to recovery for 15 min. after recovery period, 15 minutes was considered as baseline prior to 30 minutes ischemia followed by 60 minutes reperfusion. two thin stainless steel electrodes fixed on the ventricular apex and right atrium for recording the lead ii of electrocardiogram (ecg). results: there were no significant differences in heart rates between groups, and ventricular tachycardia significantly increased in chronic sleep deprivation group as compared with ir group in ischemia period. sympathectomy significantly reduced ventricular tachycardia incidence when compared with sd. there is no difference in incidence of ventricular tachycardia between control group and ir group. the incidence of ventricular fibrillation during early reperfusion was significantly augmented (p<0.05) in sleep deprivation group as compared with ir group and sympathectomy significantly could reverse ventricular fibrillation incidence to ir group level as compared with sd group (p<0.05). conclusion: induction of 72h sleep deprivation prior to ischemia and reperfusion increased the probability of ventricular tachycardia and ventricular fibrillation occurrence during ischemia and reperfusion and chemical sympathectomy could eliminate this effect.