Comparison Of Left Bundle Branch Area Pacing And Right Ventricular Pacing In Patients With Third Degree Atrioventricular Block

Objective:To evaluate the safety and effectiveness of left bundle branch regional pacing(LBBAP),the pacing parameters of left bundle branch region pacing(left bundle branch area pacing,LBBAP)and right ventricular pacing in patients wit-h third degree atrioventricular block(Ⅲ °AVB)and their effects on ECG QRS wave duration,left ventricular diastolic and systolic function were compared.Methods:A retrospective cohort study was used to collect the clinical data of 94 patients with permanent cardiac pacemaker successfully implanted in the Department of Cardiology of Yijishan Hospital of Southern Anhui Medical College from January 2019 to December 2020.A total of 94 patients were divided into two groups according to the pacing site:(1)Right ventricular pacing(RVP)group(44 cases): the ventricular electrode was implanted into the right ventricular apex(18 cases)or septum(26 cases).(2)LBBAP group(50 cases): the ventricular electrode was placed in the area of left bundle branch.The baseline data before operation,pacing threshold,perception,impedance,QRS duration of pacemaker electrocardiogram and pacing proportion during follow-up were analyzed and compared between the two groups.The related indexes of color Doppler echocardiography were left ventricular ejection fraction(LVEF),E value(mitral valve orificepeak blood flow velocity in early diastole),e’value(mitral annulus velocity),E/e’ ratio,left atrial diameter(LAD),left ventricular end-diastolic diameter(LVEDD)at 6 and 12 months after operation,and operationrelated complications such as electrode dislocation,perforation,loss and bag infection.SPSS26.0 system was used to analyze the data,and the difference was statistically significant.The safety and efficacy of left bundle branch pacing in patients with Ⅲ °AVB were evaluated.Results: 1.A total of 94 patients were selected,including 50 LBBAP and RVP44.There was no significant difference in age,sex,previous medical history(diabetes,hypertension,coronary heart disease),duration of QRS wave,LVEF,E value,e ’value,E/e,ratio and LAD between the two groups before operation(P>0.05).2.The operation time and exposure time in LBBAP group were longer than those in RVP group(P < 0.001).The difference was statistically significant(P < 0.001).3.There was no significant difference in pacing parameters between LBBAP group and RVP group.Pacing threshold [(0.65±0.1)V vs(0.64±0.08)V,P=0.609)],perception [(13.52±1.53)m V vs(13.93±1.90)m V,P=0.259],impedance[(615.42±66.08)Ω vs(13.93±1.90)Ω,P=0.259],and pacing lead parameters remained stable in both groups during medium and long-term follow-up.During the follow-up,there was no significant difference in pacing ratio between the two groups(P > 0.05).4.There was no significant difference in preoperative QRS duration between LBBAP group and RVP group [(108.18±27.28)ms vs.(114.66±28.85)ms,P=0.294].Immediately after operation,the time limit of QRS in LBBAP group was significantly shorter than that in RVP group [(97.60±12.69)ms vs.(138.18±17.27)ms,P< 0.001],and there was significant difference between the two groups.During the follow-up period,the postoperative QRS time in RVP group was significantly longer than that before operation(P< 0.05),and the postoperative QRS duration in LBBAP group was slightly shorter than that before operation,but there was no significant difference(P > 0.05).5.During the 6-month follow-up,the LVEF in the LBBAP group was higher than that in the RVP group [(62.54±3.67)% vs.(56.95±6.04)%,(P < 0.001)],and the E/e’value [(12.37 ±3.12)vs.(14.26 ±3.27,0.005)] was lower than that in the RVP group,the differences were statistically significant.LAD [(40.70 ±5.22)mm vs.(41.50±6.64)mm,(P < 0.668)],LVEDD[(48.18±5.89)mm vs.(48.43±5.63)mm,(P=0.833)],E value[(84.90 ±20.50)cm/s vs.(91.48 ±22.61)cm/s,(P < 0.01)],the differences were not statistically significant.During the 12-month follow-up,LVEF in LBBAP group was higher than that in RVP group [(64.08±3.93)% vs.(50.91±4.07)%,(P < 0.001)],LAD [(39.54±5.10)mm vs.(43.60±6.81)mm,(P < 0.001)]、E value [(80.24±16.45)cm/s vs.(98.59±20.30)cm/s,P < 0.001]、E/e ’ value [(11.80±2.90)vs.(15.77±3.50),(P<0.001)] were smaller than that in RVP group,and the differences were statistically significant,LVEDD[(47.12 ±5.64)mm vs.(49.02 ±5.45)mm,(P=0.101)] was slightly less than that in the RVP group,but the difference was not statistically significant.In LBBAP group,LVEF increased at 6 months after operation [(62.54±3.67)%vs.(60.24±5.50)%,(0.014)],and increased at 12 months after operation [(64.08±3.93)%vs.(60.24±5.50)%,(P < 0.001)].The E/e’ was significantly lower at 12 months after operation than that before operation [(11.80±2.90)vs.(13.49±3.28)(P < 0.007)].In RVP group,LVEF decreased 6 months after operation [(56.95±6.04)% vs.(62.77±7.11)%,(P < 0.001)],and 12 months after operation decreased [(50.91 ±4.07)%vs.(62.77 ±7.11)%,(P < 0.001)].LAD increased significantly compared with that before operation [(43.60 ±6.81)mm vs.(40.09 ±6.52)mm,P=0.011].6.In this study,1 patient in LBBAP group and 2 patients in RVP group had electrode dislocation during operation,and during follow-up,2 patients in RVP group had electrode dislocation one month after operation.Conclusion: 1.For patients with Ⅲ °AVB,short-term pacing parameters of LBBAP are stable and there is no increase in operation-related complications,which is as safe and effective as RVP.2.Compared with RVP,LBBAP pacing QRS has shorter duration,can maintain and improve left ventricular diastolic function and protect left ventricular systolic function,which is more physiological.