The Influence Of The Sympathetic Neural Distribution And Function On New-onset Atrial Fibrillation After Acute Myocardial Infarction

Objective:We aimed to determine the contribution of sympathetic neural remodeling to the occurrence of Atrial fibrillation after acute myocardial infarction. And to observe the influence of myocardial infarction to the AF induction rate and sympathetic neural remodeling.Methods:We randomly divided 12 dogs into 2 groups, controlled group(n=6). Model group(n=6). We applied open heart surgery without ligating the vessels in controlled group. And in model group we ligated the LCX and right atrial branch of right coronary artery to establish the AF after AMI model. We recorded different AF induction rate of different time and the amplitude also frequency of sympathetic nerve discharge. HPLC method was established to determine the density of norepinephrine, epinephrine, tyrosine hydroxylase, tyrosine hydroxylase, norepinephrine transporter in myocardium and kidney.Results:①The AF induction rate of 30 minutes after ischemia,2 hours after ischemia,4 hours after ischemia in model group was significantly higher when compared with controlled group and baseline(P<0.05)。② The amplitude and frequency of 5 minutes after ischemia,30 minutes after ischemia sympathetic nerve discharge was larger than in controlled group(P<0.05).@The density of NE and E was significantly higher when compared with controlled group(P<0.05).④ The density of TH was higher than controlled group, whereas the density of NET was lower than controlled group(P<0.05).Conclusion: Excessive sympathetic nerve activation and sympathetic nerve remodeling is observed after myocardial infarction. The occurrence of AF after AMI is closely related to the the sympathetic neural activity and remodeling.