A Clinical Comparative Study On The Pacing Of The His-Purkinje System And The Pacing Of The Right Ventricular Septum

Backgrounds:Artificial cardiac pacing is the most effective and mature treatment for symptomatic bradycardia.In the past,the most commonly used pacing site in clinical practice is the apex of the right ventricle,because the trabecula is very abundant in this site,and the fixed electrode operation here is relatively simple and very stable.However,the results of a large number of clinical randomized controlled trials show that the long-term right ventricular Right ventricular apex pacing(RVAP)can cause adverse consequences such as ventricular remodeling,cardiac insufficiency,atrial fibrillation and valvular regurgitation;Whether right ventricular septum pacing(RVSP)has more advantages than RVAP is not clear;Cardiac resynchronization therapy(Cardiac resynchronization therapy,CRT)can maintain left and right ventricular electrical and the relative synchronization of mechanical activities can improve the clinical symptoms and prognosis of patients.However,in clinical applications,some patients have difficulty in implanting the left ventricular epicardial target vein wire,and the curative effect of the pacing method is also very limited in patients with non-left bundle branch block.Affected by pacing scars,about one-third of patients have no response.In recent years,the pacing of the His-Purkinje System includes His bundle pacing(HBP)and left bundle branch area pacing(LBBaP).The sequence of atrioventricular,interventricular and intraventricular activation is currently the most physiologically physiological pacing method in clinical practice.In this study,the electrical parameters and clinical effects of the pacing of the His-Purkinje System and the right ventricular septum were compared to evaluate the safety and effectiveness of the pacing of the His-Purkinje System.Objective:By comparing and analyzing the electrical parameters and clinical effects of the pacing of the His-Purkinje System and the pacing of the right ventricular septum,the safety and effectiveness of the pacing of the His-Purkinje System are evaluated.Methods:A retrospective cohort study method was used to collect clinical data of patients who underwent pacemaker implantation in the Department of Cardiology,the First Affiliated Hospital of Zhengzhou University from January 2018 to January 2020.A total of 115 cases were included,and according to different pacing sites they were divided into RVSP group(55 cases),HBP group(27 cases)and LBBaP group(33 cases).Compare the preoperative baseline data of the three groups of patients,the length of the intraoperative operation(the time from subclavian vein puncture to capsular bag suture),X-ray exposure time and X-ray exposure dose;Three groups of pacing threshold,perception,impedance,QRS wave duration of ECG during pacing,and right ventricular pacing ratio during follow-up immediately during the operation and 3,6 and 12 months during the postoperative follow-up;Cardiac color Doppler ultrasound-related indicators,namely left ventricular ejection fraction(left ventricular ejection fraction,LVEF),left ventricular end-diastolic diameter(left ventricular end-diastolic diameter,LVEDD),tricuspid regurgitation rating(reflux degree is divided into 0-3 Grade,no reflux is grade 0,mild reflux is grade 1,moderate reflux is grade 2,and severe reflux is grade 3),Right atrium transverse diameter;Cardiac function New York Heart Association(New York Heart Association,NYHA),N-terminal pro brain natriuretic peptide(NT-proBNP)level;surgery-related complications such as wire dislocation,perforation,Loss of capture and pouch infection,etc.The data were processed by SPSS22.0,all tests were two-sided tests,and P<0.05 indicated that the difference was statistically significant.Results:1.Baseline dataThe three groups of patients had no statistical difference in age,gender,causes of pacemaker implantation,comorbidities,NYHA classification of heart function,NT-proBNP level,and cardiac color Doppler ultrasound-related indicators,namely LVEF,LVEDD,tricuspid regurgitation rating,right atrium transverse diameter,etc.(P>0.05).2.Surgery related information(1)Pacemaker implantation typeA total of 115 patients were enrolled in this study,and they were divided into RVSP group(55 cases),HBP group(27 cases)and LBaP group(33 cases)according to different pacing locations.The types of pacemaker implantation are as follows:RVSP group has 8 single-chamber pacemakers and 47 double-chamber pacemakers;HBP group has 1 single-chamber pacemaker and 26 double-chamber pacemakers;LBBaP group 3 cases of single-chamber pacemakers and 30 cases of dual-chamber pacemakers were implanted.(2)Intraoperative related indicatorsThe length of the operation time was(116.8.8±29.13)min in the HBP group,the shortest was(73.0 7±18.16)min in the RVSP group,and(80.24±16.99)min in the LBaP group.There were a statistical difference between the three groups(P<0.001).The length X-ray exposure time was(10.24±3.13)min in the HBP group,the shortest was(5.88±1.53)min in the RVSP group,and(7.29±1.68)min in the LBBaP group.There were statistical differences among the three groups(P<0.001).X-ray dose,the HBP group had the highest dose of(109.76±26.88)mGy,the RVSP group had the least(68.86±15.83)mGy,and the LBBaP group was(86.14±15.73)mGy.There were a statistically significant difference between the three groups(P<0.001).3.Surgery-related complicationsIn this study,the follow-up period was 1 year and the average follow-up period was(16.09±2.99)months.Surgery-related complications were as follows:2 patients in the LBBaP group had ventricular septal perforation during the operation;1 patient in the RVSP group had a capsular infection 11 months after the operation;1 patient in the HBP group had a capsular infection 14 months after the operation,1 patient in the HBP group,the tip electrode of the His bundle wire was dislocated 15 months after operation;there were no significant difference in the complications related to surgery between the three groups(P=0.434).4.Pacing parametersIn comparison between the three groups of patients,the HBP group had the highest threshold[intraoperative(1.21±0.87)V]in the intraoperative and follow-up periods,and the LBBaP group had the lowest threshold[intraoperative(0.76±0.47)V],there were a statistical difference in comparison the results of the three groups(P<0.001);in the pairwise comparison between the groups,the threshold of the HBP group were significantly higher than that of the RVSP group and the LBBaP group(P<0.001).In follow-up time periods,comparing the perception of the three groups of patients,the RVSP group had the highest intraoperative[immediately(12.96±2.53)mV],and the HBP group had the lowest perception[immediately(7.39±2.11)mV],compared with the three groups the difference were statistically significant(P<0.001);the results of the intra-group comparison showed that the threshold values of 6 months and 12 months after the operation in the RVSP group were significantly higher than those immediately after the operation(P<0.05),and 12 months after the operation the HBP group threshold was significantly higher than that immediately(P=0.025).There were no significant difference in impedance and pacing ratio between the three groups of patients during the follow-up period(P>0.05).5.QRS wave durationThere were no significant difference in the time of the baseline QRS wave duration between the three groups of patients before operation(P>0.05).Immediately after surgery and during follow-up,the QRS wave duration in the HBP group was the shortest[immediately after surgery(96.84±16.92)ms],and the QRS wave duration in the RVSP group was the longest[immediately after surgery(143.93 ±30.18)ms].There were a statistically significant difference in the QRS wave duration between the there groups(P<0.001);comparisons between the groups:the QRS wave duration in the RVSP group was significantly longer than that of the HBP group and the LBBaP group during the same period(P<0.001);intra-group comparison:each period of follow-up,QRS wave duration in RVSP group was significantly longer than preoperative baseline(P<0.05).6.Echocardiogram related indicators and cardiac function parametersIn the comparison between the three groups,there were no significant difference between the preoperative baseline data and the LVEDD,right atrial transverse diameter,tricuspid regurgitation rating,NT-proBNP and NYHA cardiac function grading at each time period during the follow-up process(P>0.05).Comparing LVEF at 12 months after operation the HBP group was the highest and the RVSP group was the lowest.The difference between the three groups were statistically significant(P=0.008).When comparing the two groups,the LVEF of the HBP group was significantly higher than that of the RVSP group at 12 months after the operation(P=0.003);intra-group comparison,LVEF in the RVSP group after 12 months was significantly lower than the preoperative baseline[(54.23 ± 10.46)%vs(58.84 ±9.59)%,P=0.036],the LVEF in the HBP group was significantly higher than the preoperative baseline LVEF at 12 months after surgery[(60.80±6.79)%vs(56.40 ±8.11)%,P=0.043].The tricuspid regurgitation ratings of the three groups all had a rising trend.Among them,the RVSP group 12 months after surgery compared with the preoperative baseline,there was a statistical difference(P=0.047).Conclusions:1.Compared with the pacing of the right ventricular septum,the pacing of the His-Purkinje system has a shorter QRS wave time duration,which can improve the patient’s.cardiac function and is more physiological.2.Compared with His bundle pacing,left bundle branch pacing has the characteristics of simple operation,high repeatability,and stable pacing parameters.It can overcome some of the difficulties in clinical practice of His bundle pacing.As a physiological pacing method instead of His bundle pacing.3.Compared with the pacing of the right ventricular septum,the pacing of the His-Purkinje system is equally safe and effective.