Study On The Mechanism By Which Low-Level Vagal Nerve Stimulation Regulates Heart Failure Both Electrically And Structurally

Objective Beagle Canines were given pacemaker pacing to create heart failure models.After successful making of chronic heart failure model,low-level vagus nerve stimulation was given for 8 weeks.To make illustrate the the mechanisms of low-level vagal nerve stimulation on regulating ventricular electrical and structural remodeling in canine heart failure model.Method 18 Canines were randomly divided into three groups(separately Shame-operatedgroup,Heart failure group and VNS group),since each group has six Canines.Three groups of Beagle Canines were all implanted with pacemakers.Heart failure group and VNS group were given pacemaker pacing to produce chronic heart failure model,while the shame-operated group were not given pace maker pacing.After modeling,no intervention was given in heart failure group and shame-operated group.Low-intensity vagus nerve stimulation was given in VNS canine group.At the end,make statistical analysis of the data of three Beagle Cannines for EF,LVEDD,CRP,TNF-?,Nt-proBNP,Heart rate,ERP separately before and after stimulation,and combined with Masson stain get to conclusion.Result Three groups of Beagle dogs were given a pacemaker,heart failure group and VNS group were given pacemaker pacing to make a chronic heart failure model.Compared with before and after modeling,Heart failure group: Nt-proBNP(P<0.05),EF%(P<0.05),VNS group:Nt-proBNP(P<0.05),EF%(P<0.05),heart failure models of Heart failure grop and VNS group were made successfully.After modeling,VNS group dogs were given low-intensity vagus nerve stimulation for 8 weeks.Make compare before and after the stimulation in the three groups of Beagle dogs.The shame-operated group:EF(P=0.054)?LVEDD(P=0.293)?Nt-proBNP(P=0.650)?CRP(p=0.507)?TNF-?(p=0.571)?HR(P=0.076)?ERP(p=0.372).Masson staining of myocardial tissue showed that the myocardial cells are neatly arranged,arranged in an orderly manner,and less infiltrating inflammatory cells.The heart failure group:EF(P<0.05)?LVEDD(P<0.05)?Nt-proBNP(P<0.05)?CRP(p=0.368)?TNF-?(p=0.745)?HR(P< 0.05)?ERP(p=0.430).Masson staining of myocardial tissue showed irregular myocardial cells with collagen fibers and inflammatory cell infiltration.VNS group:EF(P<0.05)?LVEDD(P=0.518)?Nt-proBNP(P<0.05)?CRP(P<0.05)?TNF-?(P<0.05)?HR(P<0.05)?ERP(P<0.05).Masson staining of myocardial tissue showed that the morphology of cardiomyocytes is relatively regular with less collagen fibers.Conclusion Low-level vagus nerve stimulation elevated EF,decreaded hemo density of Nt-proBNP?CRP?TNF-?,ERP and heart rate,delayed effective responsive peroide,inhibited ventricular remodeling,myocardia tissue degeneration and fibrillation.Low-level vagus nerve stimulation delays or even reverses remodeling of heart failure bouth electrically and structurally.