Study Of The Relationship Between Atrial Substrate Changes And Electric-Driver In Patients With Non-Paroxysmal Atrial Fibrillation Guided By High-Density Mapping

Objective:The study analyzed the relationship between high-density mapping guided left and right atrial substrate alterations and the electric-driver for the maintenance of atrial fibrillation in patients with non-paroxysmal atrial fibrillation,providing some theoretical basis for clarifying the mechanism of non-paroxysmal atrial fibrillation maintenance and exploring individualized ablation strategies.Methods:One hundred and thirty-four patients with non-paroxysmal atrial fibrillation,including 53 patients with persistent atrial fibrillation and81 patients with long-range persistent atrial fibrillation,who underwent ablation with our first HOT-AF procedure for the first time at the Atrial Fibrillation Center of the Third Xiangya Hospital of Central South University from January 2019 to August 2021 were enrolled.All patients underwent electroanatomic substrate mapping of the left and/or right atria under the guidance of CATRO3 electroanatomic mapping system before the procedure.Intraoperative electrophysiological characteristics of atrial potential dispersion,rapid excitation frequency and adjacent electrode folding or divergence tendency of the drive site is the electric-driver,using HOT-AF(High-density mapping Modified Box and Electric-driver Substrate Ablation)procedure for electric-driver substrate improvement.Different settings of bipolar voltage electrograms under high-density labeling were used to classify the left and right atrial labeling sites(criterion 1:regions with bipolar voltage<0.1mv were defined as scar areas,regions with 0.1-0.5mv were defined as low-voltage regions,and regions with bipolar voltage>0.5mv were defined as normal tissue;criterion 2:regions with bipolar voltage<0.05mv were defined as scar areas,the area with bipolar voltage 0.05-0.35mv was defined as low voltage area,and the area with bipolar voltage>0.35mv was defined as normal tissue).To compare the atrial stromal changes in patients with persistent AF with those in patients with long-range persistent AF,to analyze the correlation between the left and right atrial substrate changes and the distribution and number of electric-driver under two different standard voltage settings,and to analyze the recurrence rate of AF at 3-month and 6-month postoperative short-term follow-up and the risk factors for AF recurrence.Results:1.A total of 134 patients with non-paroxysmal atrial fibrillation underwent left atrial substrate specimen,and 58 of them also underwent right atrial substrate specimen.Under the standard 1 bipolar voltage scale:the low voltage index and total low voltage index in all regions of the left and right atria were higher in the long-range persistent AF group than in the persistent AF group,and the differences were statistically significant(P<0.05);the scar index and total scar index in all regions of the left atrium were higher in the long-range persistent AF group than in the persistent AF group,but the differences were statistically significant only in the posterior wall and the base of the left atrium(P=0.047,P=0.022).Under the standard 2 bipolar voltage scale:the low voltage index and total low voltage index in all regions of the left and right atria were higher in the long-range persistent AF group than in the persistent AF group,and the differences were statistically significant(P<0.05);the scar index and total scar index in all regions of the left and right atria were higher in the long-range persistent AF group than in the persistent AF group,but there was no statistical difference(P>0.05).2.A total of 359 electric-driver were labeled in the left atrium in 134patients with non-paroxysmal AF,with a mean of(2.68±1.19)driver per case,of which a total of 7 electric-driver were labeled in 58 patients who required simultaneous right atrial labeling for surgery.The electric-driver are mostly located in the low-voltage zone transition area(the junction of the normal voltage region of the myocardium shifting into the low-voltage zone and the junction of the different color transitions of the low-voltage zone),and their atrial zones are distributed as follows:anterior wall of the left atrium(237/359,66.0%),posterior wall of the left atrium(78/359,21.7%),top of the left atrium(27/359,7.5%),base of the left atrium(6/359,1.7%),lateral wall of the left atrium(5/359,1.4%),left atrial septum(0%),base of the left auricle(6/359,1.7%).The distribution of total electric-driver was statistically greater in patients with long-range persistent AF than in patients with persistent AF in the left atrium(1/7,14.3%),right atrial septum(1/7,14.3%),right atrial superior vena cava(2/7,28.6%),and right atrial tricuspid annulus(3/7,42.8%),and the difference was statistically significant(P<0.001),while the distribution of total electric-driver in the right atrium the distribution was not statistically significant(P=0.835).The main manifestations of atrial electric-driver in the atrial were rotation-like(272/366,74.3%),micro-folded(2/366,0.5%)focal electric-drivers,and in a few cases,typical atrial flutter(34/366,9.3%)and atypical atrial flutter(58/366,15.9%)with large folded electric-drivers.3.There was a positive correlation between the left atrial low voltage index and the number of electric-driver at different standard voltage value settings(r1=0.437 vs.r2=0.615;P=0.047),suggesting that the bipolar voltage 0.05-0.35mv voltage value setting better reflects the relationship between left atrial substrate changes and electric-driver.4.The simple linear regression results suggested that there was a linear relationship between the left atrial low voltage index and the number of electric-driver F(1,134)=80.397,(P<0.001),and that the low voltage index explained 37.4%of the variation in electric-driver(adjusted R~2=37.4%)with the following regression equation:total electric-driver=0.350+(5.596*total left atrial low voltage index),and the predicted value of the minimum total LVI possible to generate electric-driver was 11.61%(95%CI 0.59-1.40).5.To analyze the recurrence rate at 6 months of short-term postoperative follow-up in the sinus transfer group versus the electro-reentry group in patients undergoing HOT-AF surgery,the recurrence rate of atrial arrhythmias were 9.3%and 24.1%in the sinus transfer group versus the electro-reentry group at 6 months postoperatively(P=0.045),the recurrence rate of simple atrial fibrillation at 6 months postoperatively was2.3%and 13.2%in the sinus transfer group versus the electro-reentry group,respectively(P=0.048),which were statistically different;the distribution of electric-driver in the sinus transfer group versus the electro-reentry group postoperatively(2.26±1.21 vs.2.90±1.15,P=0.004),which was statistically different.In the multifactorial analysis it was suggested that the left atrial internal diameter(OR=1.142,95%CI 1.020-1.280,P=0.022),number of electric-driver(OR=2.348,95%CI 1.463-3.769,P<0.001)may be risk factors for AF recurrence.Conclusion:1.Long-range persistent atrial fibrillation has more pronounced atrial substrate changes than persistent atrial fibrillation,manifested by an increase in the low-voltage and scar zones,with significant differences in the low-voltage zone changes.2.The electric-driver under atrial fibrillation rhythm are mostly located in the low-voltage zone transition area,the bipolar voltage is 0.05-0.35mv voltage value setting is more responsive to the relationship between the left atrial substrate changes and electric-driver;there is a high positive correlation between the total left atrial low-voltage zone index and the number of electric-driver,and when the total left atrial low-voltage zone area is greater than 11.61%of the total left atrial area may generate electric-driver.3.The"multiple electric-driver mechanism"including focal electric-driver and large fold electric-driver based on atrial substrate changes may be the electrophysiological maintenance mechanism of non-paroxysmal AF4.Individualized electric-driver ablation may reduce the rate of postoperative AF recurrence in non-paroxysmal AF ablation.Number of electric-driver may be risk factor predicting postoperative atrial fibrillation recurrence in patients with non-paroxysmal atrial fibrillation.