Study On The Effect Of Radiofrequency Ablation Guided By Ablation Index In The Treatment Of AVNRT

BackgroundAtrioventricular nodal reentrant tachycardia is a kind of tachycardia with the participation of atrioventricular nodal reentrant mechanism.The majority of the patients were young people and women.The attack of atrioventricular nodal reentrant tachycardia often shows sudden onset and stop,and most people show paroxysmal tachycardia,palpitation,dizziness,chest pain and so on.In severe cases,hypotension,shock,syncope and even sudden death may occur.Atrioventricular nodal reentrant tachycardia can be relieved by stimulation of vagus nerve and application of antiarrhythmic drugs.In the treatment centers with rich experience about ablation treatment,the success rate of radiofrequency ablation in patients with atrioventricular nodal reentrant tachycardia can be as high as 90%or more.Transcatheter ablation has become a first-line treatment for atrioventricular nodal reentrant tachycardia.In the initial stage of transcatheter radiofrequency ablation in the treatment of atrioventricular nodal reentrant tachycardia,the main equipment used is a two-dimensional image positioning system,and there was no intuitive reference for the spatial position of the ablation catheter in the cardiac cavity.Contact force and ablation time depend on the operators’ hand-feeling and experience.If that ablation discharge is insufficient,ablation injury is not enough to cause irreversible electrical conduction system injury,low success rate of operation and high incidence of complications.And patients and operators need to be exposed to X-ray for a long time when using two-dimensional image positioning system.The comprehensive application of three-dimensional system and contact force catheter can real-timely display the three-dimensional structure of cardiac cavity,the position of catheter in cardiac cavity and catheter-tissue contact force,and the application of three-dimensional system and pressure catheter can shorten the operation time,improve the success rate of operation,reduce the incidence of operative complications,and reduce X-ray exposure time and X-ray exposure.However,the diameter of the ablation electrode of the three-dimensional system is different from that of the two-dimensional ablation electrode,and the injury area is larger.Since the ablation parameters such as ablation power and ablation time still follow the ablation parameter standards of the two-dimensional system.In some cases,there is a risk of excessive ablation or even serious injury to the electrical conduction system.The ablation index quantifies the ablation index by integrating ablation power,contact force and ablation time.Studies have shown that with the increase of ablation power and ablation time,the degree of ablation injury increases,the ablation success rate increases,but the incidence of complications increases.On this basis,some scholars put forward the high power and short duration ablation method,and proved that the ablation injury range can be effectively controlled by animal experiments in vitro.When the ablation index is relatively constant,the ablation time is shortened with the increase of ablation power,which can be used to guide the ablation treatment mode of high power and short time.Ablation index is more and more used in radiofrequency ablation of atrial fibrillation.Data from several clinical treatment centers show that ablation index guiding radiofrequency ablation in the treatment of atrial fibrillation can effectively reduce the number of ablation,shorten the ablation duration,reduce the occurrence of complications,and do not reduce or even increase the success rate,while the application of ablation index in radiofrequency ablation of atrioventricular nodal reentrant tachycardia is rarely reported.ObjectiveTo explore the safety and efficacy of quantitative ablation guided by ablation index in the treatment of atrioventricular nodal reentrant tachycardia and to explore the ablation index value of safe and effective radiofrequency ablation in the treatment of atrioventricular nodal reentrant tachycardia.MethodA total of 84 patients with atrioventricular nodal reentrant tachycardia underwent radiofrequency ablation from January to October 2020 in the Department of Cardiology of the First Affiliated Hospital of Zhengzhou University.According to the different surgical methods,the patients were divided into two groups:contact force guided radiofrequency ablation group(CF group)and ablation index guided radiofrequency ablation group(AI group).CF group used contact force to guide radiofrequency ablation for atrioventricular nodal reentrant tachycardia,AI group used ablation index to guide radiofrequency ablation for atrioventricular nodal reentrant tachycardia.The general baseline data of the two groups(age,sex,age of onset,time of disease load,left ventricular diameter,left ventricular ejection fraction,basal heart rate,height,weight,body mass index,associated underlying diseases,etc.)were analyzed by SPSS25.0 statistical software.So did other indices,including operation time related indices(operation duration,effective ablation time,X-ray exposure time),operation parameter related indices(ablation power,catheter-tissue contact force,AI value),safety indices(incidence of fast junction rhythm,incidence of transient atrioventricular block,incidence of persistent atrioventricular block),effective indices(ablation discharge times,effective rate of single ablation,The differences in the incidence of tachycardia atrial echo and no slow pathway phenomenon),the incidence of complications(immediate complications and long-term complications),and the success rate(immediate success rate and long-term success rate).The difference was statistically significant.ResultsA total of 84 patients were included in this study,including 42 patients in the contact force guided radiofrequency ablation group and 42 patients in the radiofrequency ablation group guided by ablation index.There was no significant difference in age,sex,age of onset,time of disease load,left ventricular diameter,left ventricular ejection fraction,basal heart rate,height,weight,body mass index and underlying diseases(coronary heart disease,hypertension,diabetes)between the two groups.There was comparability between the two groups(all P>0.05).Compared with CF group,the operation duration of AI group was shorter(68.45±8.11 vs 47.40 ±4.16,P<0.001)and the effective ablation time was less(113.57 ± 15.59 vs 59.05 ± 12.84,P<0.001),and the difference is statistically significant.Whereasa,the X-ray exposure time(5.69±1.04 vs 5.38±0.76,P=0.122)was similar,and the difference was not statistically significant.In terms of operative parameters,the ablation power(25.00±4.42 vs 27.74±4.01,P=0.004)in CF group and AI group is statistically significant different.There was no significant difference in catheter-tissue contact force between CF group and AI group(8.24 ± 1.56 vs 8.21±1.34,P=0.940).In terms of procedural safety parameters,the incidence of fast junctional rhythm was(2.4%vs 0.0%,P=1.000)in the CF group versus the AI group,the incidence of transient Atrioventricular block was(2.4%vs 0.0%,P=1.000)between the CF group and the AI group,and the incidence of persistent Atrioventricular block was(0.0%vs 0.0%),with no statistically significant differences.In terms of the effectiveness of the procedure parameters,the number of ablation discharges in the CF and AI groups was(3.31±1.76 vs.1.52 ± 0.83 P<0.001),and the single ablation efficiency was(18.2%vs.66.7%,P<0.001),with a statistically significant difference in the number of ablation discharges and higher single ablation efficiency in the AI group compared with the CF group.The incidence of tachycardia was(0.0%vs.0.0%),which was not statistically different,and the incidence of atrial echo was(4.8%vs.0.0%,P=0.433)in the CF and AI groups,which was not statistically different,and the percentage of slow conduction-free phenomenon was(95.2%vs.88.1%,P=0.433)in the CF and AI groups,which was not statistically significant.There were no intraoperative or postoperative complications between patients in the CF and AI groups,and there was no difference in the immediate complication rate(0.0%vs.0.0%)and the distant complication rate(0.0%vs.0.0%).The immediate surgical success rate of patients in the CF and AI groups was(0.0%vs 0.0%),which did not differ.And the distant surgical success rate of patients in the CF and AI groups was(90.9%vs 100.0%,P=0.494),but the difference was not statistically significant.ConclusionAblation index-guided radiofrequency ablation for atrioventricular node folding tachycardia can significantly shorten the procedure time,reduce the effective ablation time,reduce the number of ablations,and improve the single ablation efficiency.Ablation index-guided quantitative ablation for AVNRT is safe and effective,and AI values of 500-550 can be used for routine quantitative ablation for AVNRT.