| Objective Acute myocardial infarction(AMI)is a critical cardiovascular disease that seriously threatens human life and health.The myocardial infarction characteristics of right coronary artery infarction is different from that of left anterior descending branch.In this study,myocardial ischemia-reperfusion model was established by ligating the right coronary artery in rabbits.The changes of autonomic nervous function and inflammatory response during ischemia-reperfusion of the right coronary artery were observed,and the effects of vagus nerve on reperfusion and inflammatory response were observed by cutting the vagus nerve to intervene in autonomic nervous function.Methods Eighteen healthy New Zealand white rabbits were randomly divided into sham operation group(S group),ischemia reperfusion group(IR group)and vagotomy group(P group).Myocardial ischemia-reperfusion model was established by reversible ligation of right coronary artery for 30 minutes and reperfusion for 2hours.The changes of ECG on rabbit body surface were detected to determine the type and severity of arrhythmia in each group;The heart rate variability(HRV)was analyzed by dynamic electrocardiograph at different periods(before ligation,30 minutes of ischemia,2 hours of reperfusion)and the heart rate deceleration force(DC)was calculated.The levels of serum inflammatory factors,including C-reactive protein(CRP),interleukin(IL)and tumor necrosis factor-?(TNF-?),were measured by enzymelinked immunosorbent assay(ELISA).Results1.Compared with group S,bradyarrhythmias and tachyarrhythmias occurred in both IR and P groups during ischemia.Bradyarrhythmia occurred in 1 case of IR group at the early stage of reperfusion without tachyarrhythmia.In group P,bradyarrhythmia was not observed at the early stage of reperfusion,but tachyarrhythmia occurred in 2 cases.2.Compared with group S,SDNN significantly increased [(140.167±59.069)ms vs.(63.167±19.599)ms,P=0.014],RMSSD significantly increased [(168.333±47.140)ms vs.(76.833±16.817)ms,P=0.003],PNN50 significantly increased[(45.500±15.338)vs.(24.667±8.300),P=0.028],the difference was statistically significant.Compared with IR group,SDNN in P group decreased significantly[(50.667±23.407)ms vs.(118.000±44.572)ms,P=0.005],RMSSD significantly decreased [(49.000±16.693)ms vs.(97.167±37.997)ms,P=0.009],PNNN50 significantly decreased [(14.500±6.5513)vs.(28.000±10.231),P=0.012],the difference was statistically significant.3.Compared with group S,TNF? increased significantly in group IR after 30 minutes of ischemia [(260.982±60.788)vs.(93.106±33.952),P=0.004],IL-1? increased significantly [(23.673±3.857)vs.(15.267±3.945),P=0.011],CRP increased significantly[(25.494±6.435)vs.(16.082±1.316),P=0.033].Compared with IR group,TNF? in P group increased significantly [(423.436±101.420)vs.(297.447±86.718),P=0.043],IL-1? increased significantly[(23.998±2.578)vs.(17.787±4.856),P=0.033],CRP increased significantly[(28.896±5.995)vs.(20.678±5.811),P=0.040],the difference was statistically significant.Conclusions1.Right coronary artery ischemia can lead to different types of arrhythmias.In the early stage of reperfusion,bradyarrhythmias mainly occur in IR group,while tachyarrhythmias are more likely to occur in P group.2.Autonomic nerve function changes during ischemia-reperfusion of right coronary artery.When myocardial ischemia occurs,the heart rate variability index(HRV),RMSSD,PNN50 and heart rate deceleration force(HRD)all increase significantly,which indicates that vagus nerve activity increases and sympathetic nerve activity decreases relatively at this time.When the blood vessel is opened,these indexes decrease gradually.When the right vagus nerve is cut off during reperfusion,the results indicate that these indexes decrease faster.3.Inflammation is involved in ischemia-reperfusion of right coronary artery.When myocardial ischemia occurs,inflammation begins and inflammatory factors increase significantly.After reperfusion,inflammatory factors in serum first increased,and then decreased with time.After vagotomy during reperfusion,the increase of inflammatory factors in serum was more obvious. |
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