The Effect Of The Autonomic Nervous Function After Circumferential Pulmonary Vein Isolation For Paroxysmal Atrial Fibrillation

Objective:To evaluate the effect of the autonomic nervous function after circumferentialpulmonary vein isolation(CPVI) for paroxysmal atrial fibrillation(PAF) by analyzing thechanges of the heart rate variability(HRV).Methods:Successful CPVI was achieved in50consecutive patients with atrial fibrillation(PAFgroup).Serial24h-Holter recordings were obtained before and3days,1months,3monthsafter CPVI to analyse the HRV.The average HR,the time-and frequency-domain(SDNN,rMSSD,LnHF,LnLF,LF/HF) analyses of HRV were obtained by the24h-Holter.All these parameters were compared between pre-and post-operation,between groups withand without PAF recurrences.Logistic regression analysis was performed to determineindependent predictors of PAF recurrence among the patient characteristics, average HRand HRV at3days after CPVI. Meanwhile, select32healthy individuals as normal control(control group). Average HR and HRV before CPVI were compared between controlgroup and PAF group.Results:①PAF group,thirty-five PAF patients (20males) meet the analysis criterion,withmean age of60.6±6.8(44-73)years, mean duration of PAF6.4±7.1(1-30)years,mean leftatrial diamension (LAD)39.7±4.8(31-53)mm，mean left ventricular ejection fraction(LVEF)68±7%(45%-75%).Among these patients,26were free from PAF (non-recurrencegroup) and9had late PAF recurrences (recurrence group) at3-month follow-up.The first of success ratio was about74.3%.②In the PAF group, average HR and LF/HF weresignificantly lower and other data (SDNN,rMSSD,LnHF,LnLF) were significantly higherthan in the control group (P<0.001).③At3days after CPVI,rMSSD and LnHF power weresignificantly lower in the non-recurrence group than in the recurrence group (P<0.05).Butthere were no significant differences between the recurrence group and the non-recurrencegroup in average HR,SDNN,LnLF and LF/HF(P>0.05).④In the non-recurrence group,average HR increased at3days after CPVI and remained elevated for3months atleast(P<0.05).The time-and frequency-domain HRV parameters,including theSDNN,rMSSD,LnLF and LnHF,decreased at3days after CPVI and remained attenuatedfor3months at least (P<0.05).In the recurrence group, there were no significantdifferences between the pre-and the post-operation in average HR andHRV(P>0.05).There was no significant differences between the recurrence group and thenon-recurrence group in LF/HF(P>0.05).⑤By multivariate Logistic regressionanalysis,only the rMSSD at3days after CPVI was an independent predictor of PAFrecurrence(OR=1.036,95%CI1.004-1.069,p=0.029).Conclusions:①CPVI is a safe and effective technique for PAF patients.②The vagal activation increased in the PAF patients.③The vagal system function damaged during CPVI might be one of the mechanisms ofhealing PAF.④Long-lasting vagal denervation could help prevent late PAF recurrence after CPVI.⑤The rMSSD at3days after CPVI was an independent predictor of PAF recurrence.