| Objectives:Our study was aimed to investigate the anatomical characteristics of pulmonary vein antrum(PVA)area,as well as to evaluate the efficacy and safety of an optimized circumferential pulmonary vein ablation(CPVA)strategy in atrial fibrillation(AF)patients.Methods:(1)The pulmonary veins(PV)were obtained from 15 healthy pigs.Using the clock face method to label the PVA,PVA-LA(left atrium)and PV area.HE staining,Masson staining and immunohistochemical staining(using the polyclonal antibody PGP9.5)were performed.The characteristics of PVA area were observed and quantified using ImagePro software.(2)Continuously recruited patients with AF in the Department of Cardiology,PLA General Hospital from June 2015 to June 2017.Fast anatomic mapping(FAM)was used and combined with the Carto-merge mapping technique,then we got the most precise anatomy model of PVA and LA.Based on that precise model,an optimized ablation strategy was proposed.According to different ablation strategies,patients were divided into three groups:group A(PVA-LA group,ablation line was designed on the atrial side 10 mm from the PVA);group B(PVA-PV group,ablation line was designed on the PV side 10 mm from the PVA);group C(PVA group,ablation line was within 10mm of PVA line).Several biomarkers including CRP,IL-6,NT-proBNP,CXCL10,CCL20 and CCL22 were detected at preoperatively.All cases completed scheduled follow-up.One-way ANOVA and post-hoc methods were used for univariate analysis.Kaplan-Meier curve was used to evaluate the efficacy of different ablation strategies in AF patients.Results:(1)The pathological sections of 15 healthy pigs were obtained.?The myocardial architecture was highly variable in normal PVA.The average length of atrial myocardium within PV was 10.95±5.6 mm,and the thickness was 1.10±0.4 mm.?The average diameter of the ganglion was 61±24 ?m.The highest density of nerve fibers was found in the region of PVA(P<0.05),with the density of 1.98±1.23/mm2 in the PVA,0.21±0.13/mm2in the LA,and 0.98±0.35/mm2 in PV.In the superior PV area there was a significantly higher density of ganglions in the superior walls than in the inferior walls(P<0.05).(2)Our study enrolled 173 cases of AF.?There was no statistically significant difference in clinical characteristics among the three groups(P>0.05).?The ablation time among three groups was significantly different(P<0.05).The ablation time in group A was significantly longer than that in group B(group A:120.67±13.12 min vs.group B:116.24±18.13 min,P<0.05).?The number of immediately successful isolation cases was 146/173(84.39%).The successful ablation rate in sub-group of paroxysmal AF was 98.04%in group A,87.18%in group B and 95.92%in group C.In sub-group of persistent AF,this rate was 40%in group A,37.50%in group B and 37.50%in group C.No significant difference was found in the electrical cardioversion rate of AF(40%vs.37.50%vs.37.50%,P>0.05).? The levels of IL-6,CXCL10,CCL20 and CCL22,were significantly different among the groups at the three-period time(P<0.05).?After 12 month follow-up,the total success ablation rate in sinus rhythm maintenance in was 83.23%(134/161).The success ablation rate group A was higher than group B and group C(89.83%vs.73.33%vs.80.70%).Conclusions:Our study found that the myocardial architecture was highly variable in normal PVA.The complex arrangement in fibrosis may produce greater non-uniform anisotropic properties,which may result in a change to AF substrate.There were abundant nerve fibers and ganglion plexus in PVA area,mainly located in the epicardial side of the fat pad.We detected a higher density of nerves in PVA,which prone to atrial arrhythmic tissue anatomy.An optimized CPVA line could be designed at the atrial side 10 mm from the PVA,by using FAM of the Carto 3 imaging system,combined CT images with Carto-merge mapping.This optimized radiofrequency ablation strategy could improve the long-term outcomes of AF therapy. |
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