Left bundle branch pacing vs biventricular pacing in heart failure patients with left bundle branch block:A systematic review and meta-analysis

BACKGROUND Left bundle branch pacing(LBBP)is a novel pacing modality of cardiac resynchronization therapy(CRT)that achieves more physiologic native ventricular activation than biventricular pacing(BiVP).AIM To explore the validity of electromechanical resynchronization,clinical and echocardiographic response of LBBP-CRT.METHODS Systematic review and Meta-analysis were conducted in accordance with the standard guidelines as mentioned in detail in the methodology section.RESULTS In our analysis,the success rate of LBBP-CRT was determined to be 91.1%.LBBP CRT significantly shortened QRS duration,with significant improvement in echocardiographic parameters,including left ventricular ejection fraction,left ventricular end-diastolic diameter and left ventricular end-systolic diameter in comparison with BiVP-CRT.CONCLUSION A significant reduction in New York Heart Association class and B-type natriuretic peptide levels was also observed in the LBBP-CRT group vs BiVP-CRT group.Lastly,the LBBP-CRT cohort had a reduced pacing threshold at follow-up as compared to BiVP-CRT.

Left bundle branch area pacing:A new era of cardiac resynchronization therapy?

The recent systematic review and meta-analysis provided a comprehensive focus on the current state of cardiac resynchronization therapy(CRT).The authors determined the feasibility of physiological left bundle branch area pacing(LBBAP)in patients indicated for CRT through a careful analysis of trials.They found that LBBAP was associated with significant reductions in QRS duration,New York Heart Association functional class,B-type natriuretic peptide levels,and pacing thresholds as well as improvements in echocardiographic parameters compared to biventricular pacing.

Management of a patient with an unusual trajectory of a temporary trans-venous pacing lead

Perforation of the right ventricle during placement of pacing wires is a welldocumented complication and can be potentially fatal.Use of temporary pacemaker,helical screw leads and steroids use prior to implant are recognised as risk factors for development of post-permanent pacemaker effusion.We reported an unusual case of pacing wire perforating interventricular septum into the left ventricle that occurred during the implant procedure performed in another institution.After the preoperative work-up and transfer to our tertiary cardiothoracic centre,the patient underwent successful surgical management.In conclusion,early recognition and timely diagnosis using advanced multimodality imaging can guide surgical intervention and prevent unfavourable consequences of device-related complications.

Dual-chamber pacing confers better myocardial performance and improves clinical outcomes compared to single-chamber pacing

The deleterious effects of long term right ventricular pacing are increasingly being recognized today.Current clinical practice favors the implantation of dual-chamber permanent pacemaker which maintains atrioventricular synchrony and is associated with better quality of life.However,despite the popular belief and common sense surrounding the superiority of dual-chamber pacing over single chamber pacing,the same has never been conclusively verified in clinical trials.Some observational evidence however,does exists which supports the improved cardiac hemodynamics,lower the rate of atrial fibrillation,heart failure and stroke in dual-chamber pacing compared to single-chamber pacing.In the index study by Haque et al,right ventricular pacing,particularly in ventricular paced,ven-tricular sensed,inhibited response and rate responsive pacemaker adversely im-pacted the left ventricular functions over 9-months compared to dual pacing,dual sensing,dual responsive and rate responsive pacemaker.Although there are key limitations of this study,these findings does support a growing body of evidence reinstating the superiority of dual chamber pacing compared to single chamber pacing.

Comparison of electrocardiogram characteristics between left bundle branch pacing and right ventricular septal pacing in patients receiving pacemaker therapy

Background and Objective Cardiac pacing is an effective therapy in patients with bradycardia.Conventional right ventricular(RV)pacing is the source of ventricular dyssynchrony,leading to unfavorable clinical outcome.This study compared the electrocardiogram(ECG)characteristics during left bundle branch pacing(LBBP)with that during RV septal pacing(RVSP)which has been thought to be better than RV apical pacing.

Right ventricular septal pacing: Safety and efficacy in a long term follow up

AIM: To evaluate the safety and efficacy of the permanent high interventricular septal pacing in a long term follow up, as alternative to right ventricular apical pacing. METHODS: We retrospectively evaluated:(1) 244 patients(74 ± 8 years; 169 men, 75 women) implanted with a single(132 pts) or dual chamber(112 pts) pacemaker(PM) with ventricular screw-in lead placed at the right ventricular high septal parahisian site(SEPTAL pacing);(2) 22 patients with permanent pacemaker and low percentage of pacing(< 20%)(NO pacing);(3) 33 patients with high percentage(> 80%) right ventricular apical pacing(RVA). All patients had a narrow spontaneous QRS(101 ± 14 ms). We evaluated New York Heart Association(NYHA) class, quality of life(Qo L), 6 min walking test(6MWT) and left ventricular function(end-diastolic volume, LV-EDV; end-systolic volume, LVESV; ejection fraction, LV-EF) with 2D-echocardiography. RESULTS: Pacing parameters were stable duringfollow up(21 mo/patient). In SEPTAL pacing group we observed an improvement in NYHA class, Qo L score and 6MWT. While LV-EDV didn't significantly increase(104 ± 40 m L vs 100 ± 37 m L; P = 0.35), LV-ESV slightly increased(55 ± 31 m L vs 49 ± 27 m L; P = 0.05) and LV-EF slightly decreased(49% ± 11% vs 53% ± 11%; P = 0.001) but never falling < 45%. In the RVA pacing control group we observed a worsening of NYHA class and an important reduction of LV-EF(from 56% ± 6% to 43% ± 9%, P < 0.0001).CONCLUSION: Right ventricular permanent high septal pacing is safe and effective in a long term follow up evaluation; it could be a good alternative to the conventional RVA pacing in order to avoid its deleterious effects.

The importance of avoiding unnecessary right ventricular pacing in clinical practice

Symptomatic bradycardia is effectively treated with the implantation of a cardiac pacemaker. Although a highly successful therapy, during recent years there has been a focus on the negative effects associated with longterm pacing of the apex of the right ventricle(RV). It has been shown in both experimental and clinical studies that RV pacing leads to ventricular dyssynchrony, similar to that of left bundle branch block, with subsequent detrimental effects on cardiac structure and function, and in some cases adverse clinical outcomes such as atrial fibrillation, heart failure and death. There is substantial evidence that patients with reduced left ventricular function(LVEF) are at particular high risk of suffering the detrimental clinical effects of long-term RV pacing. The evidence is, however, incomplete, coming largely from subanalyses of pacemaker and implantable cardiac defibrillator studies. In this group of patients with reduced LVEF and an expected high amount of RV pacing, biventricular pacing(cardiac resynchronization therapy) devices can prevent the negative effects of RV pacing and reduce ventricular dyssynchrony. Therefore, cardiac resynchronization therapy has emerged as an attractive option with promising results and more clinical studies are underway. Furthermore, specific pacemaker algorithms, which minimize RV pacing, can also reduce the negative effects of RV stimulation on cardiac function and may prevent clinical deterioration.

Right Ventricular Outflow Tract Septal Pacing versus Apical Pacing: A Prospective, Randomized, Single-blind 5-Years Follow-up Study of Ventricular Lead Performance and Safety

Summary： Lead placement for ventricular pacing variably impacts the physiological benefit of the pa- tient. This study evaluated the ventricular lead performance and safety of right ventricular outflow tract septal pacing in patients with bradyarrhythmia in South China over 60-month follow-up. Totally, 192 patients （108 males, and 84 females, 63-4-21 years old） with bradyarrhythmia were randomly divided into two groups. The right ventricular outflow tract septum （RVOTs） group had lead placement near the sep- tum （n=97）, while the right ventricular apex （RVA） group had a traditional apical placement （n=95）. RV septal lead positioning was achieved with a specialized stylet and confirmed using fluoroscopic projec- tion. All patients were followed up for 60 months. Follow-up assessment included stimulation threshold, R-wave sensing, lead impedance and lead complications. The time of electrode implantation in both the ROVTs and RVA groups were significantly different （4.29±0.61 vs. 2.16±0.22 min; P=0.009）. No dif- ferences were identified in threshold, impedance or R-wave sensing between the two groups at 1 st, 12th, 36th and 60th month during the follow-up period. No occurrence of electrode displacement, increased pacing threshold or inadequate sensing was found. The long-term active fixation ventricular electrode performance in RVOTs group was similar to that in RVA group. RVOTs pacing near the septum using active fixation electrodes may provide stability during long-term follow-up period.

Cardiac resynchronization therapy improved the clinical outcomes in pacemaker patients upgraded to biventricular device

The right ventricular pacing （RVP） is the standard treat- ment for patients with severe bradyarrhythmias; however, it may cause and exacerbate heart failure symptoms in a long run under some circumstances.{1] In fact, significant left ventricular （LV） systolic dysfimction and symptomatic heart failure （HF） is commonly found in patient population with pacemaker implantations.

Minimizing right ventricular pacing in sinus node disease: Sometimes the cure is worse than the disease

Traditional right ventricular(RV) apical pacing has been associated with heart failure, atrial fibrillation and increased mortality. To avoid the negative consequences of RV apical pacing different strategies have been developed, among these a series of pacing algorithms designed to minimize RV pacing. These functions are particularly useful when there is not the need for continuous RV pacing: intermittent atrioventricular blocks and, mainly, sinus node disease. However, in order to avoid RV pacing, the operationalfeatures of these algorithms may lead to adverse(often under-appreciated) consequences in some patients. We describe a case of a patient with sinus node disease, in whom right atrial only pacing involved long atrio-ventricular delay to allow intrinsic ventricular conduction, which led to symptomatic hypotension that could be overcome only by "forcing" also right ventricular apical pacing. We subsequently discuss this case in the context of current available literature.

Implantation of Lumenless Pacing Leads at the Inter-atrial Septum and Right Ventricular Outflow Tract with Deflectable Catheter-sheath

Current permanent right ventricular and right atrial endocardial pacing leads are implanted utilizing a central lumen stylet. Right ventricular apex pacing initiates an abnormal asynchronous electrical activation pattern, which results in asynchronous ventricular contraction and relaxation. When pacing from right atrial appendage, the conduction time between two atria will be prolonged, which results in heterogeneity for both depolarization and repolarization. Six patients with Class Ⅰ indication for permanent pacing were implanted with either single chamber or dual chamber pacemaker. The SelectSecure 3830 4-French （Fr） lumenless lead and the SelectSite C304 8.5-Fr steerable catheter-sheath （Medtronic Inc., USA） were used. Pre-selected pacing sites included inter-atrial septum and right ventricular outflow tract, which were defined by ECG and fluoroscopic criteria. All the implanting procedures were successful without complication. Testing results （mean atrial pacing threshold： 0.87 V; mean P wave amplitude： 2.28 mV; mean ventricular pacing threshold： 0.53V; mean R wave amplitude： 8.75 mV） were satisfactory. It is concluded that implantation of a 4-Fr lumenless pacing lead by using a streerable catheter-sheath to achieve inter-atrial septum or right ventricular outflow tract pacing is safe and feasible.

Hemodynamic improvement by right ventricular septal pacing in elderly patients with chronic atrial fibrillation and slow ventricular response

Background and objectives Right ventricular apical(RVA)pacing has been reported impairing left ventricular(LV)performance.Alternative pacing sites in right ventricle(RV)has been explored to obtain better cardiac function.Our study was designed to compare the hemodynamic effects of right ventricular septal(RVS)pacing with RVA pacing.Methods Ten elderly patients with chronic atrial fibrillation(AF)and long RR interval or slow ventricular response(VR)received VVI pacing.The hemodynamic difference between RVS and RVA pacing were examined by transthoracic echocardiography(TTE).Results Pacing leads were implanted successfully at the RVA and then RVS in all patients without complication.The left ventricular(LV)parameters,measured during RVA pacing including left ventricular ejection fraction(LVEF),FS,stroke volume(SV)and peak E wave velocity(EV)were decreased significantly compared to baseline data,while during RVS pacing,they were significantly better than those during RVA pacing.However,after 3-6 weeks there was no statistical significant difference between pre-and post-RVS pacing.Conclusions The LV hemodynamic parameters during RVA pacing were significantly worse than baseline data.The short term LV hemodynamic parameters of RVS pacing were significantly better than those of RVA pacing;RVS pacing could improve the hemodynamic effect through maintaining normal ventricular activation sequence and biventricular contraction synchrony in patients with chronic AF and slow ventricular response.

Long-term follow-up of right ventricular outflow tract septal pacing

Objective Right ventricular outflow tract septum has become widely used us an electrode placement site. However, data concerning lead performances and complications for lead repositioning with this technique were scant. The purpose of this study was to observe long- term lead performances and complications of right ventricular outflow tract septal pacing and provide evidences for choosing an optimal electrode implantation site. Methods Thirty-six patients with septal active electrode implantation and 39 with apical passive electrode implantation were enrolled in this study. Pacing threshold, R-wave sensing, lead impedance, pacing QRS width and pacing-related compli- cations for two groups at implantation and follow-up were compared. Results There were higher pacing threshold and shorter pacing QRS width at implantation in the septal group compared with the apical group. There were no differences between the septal and the apical groups in pacing threshold, R-wave sensitivity, lead impedance and pace-related complication during a follow-up. Conclusions Right ventricular outflow tract septum could be used as a first choice for implantation site because it had long-term stable lead performances and no serious complications compared with the traditional apical site.

Comparison of His-purkinje bundle pacing and right ventricular inflow tract septal pacing in the elderly

Objective To compare the short-term clinical effect and electrical parameters of His-purkinje bundle pacing(HPBP) and right ventricular inflow tract septal pacing(RVIP) in the elderly. Methods Between April 2017 and September 2019, sixty patients with indications for permanent cardiac pacing and resynchronization therapy in Beijing Anzhen Hospital were divided into the HPBP and RVIP groups, and were analyzed. A ventricular pacing lead was implanted in left ventricular septal sites with left bundle potentials or His potentials in the HPBP group. The lead was placed in right ventricular inflow tract septal sites close to distal His-bundle regions without potentials from the His-purkinje conduction system in the RVIP group. Lead impedance, R wave amplitude, pacing thresholds, QRS duration, left ventricular ejection fraction(LVEF), and left ventricular end-diastolic diameter(LVEDD), mitral regurgitation area reflux, QTc, T wave directivity, Tp-e and Tp-e/QT ratio were compared between the HPBP and RVIP groups during the procedure and the short-month follow-up. Results No significant differences were found in lead impedance, R wave amplitude, QRS duration, LVEF, LVEDD, mitral regurgitation area reflux, QTc, T wave directivity, Tp-e and Tp-e/QT ratio between the HPBP and RVIP groups. However, the pacing threshold was significantly lower in the HPBP group than in the RVIP group(0.7 ± 0.2 vs. 0.9 ± 0.3 V, P = 0.02). Conclusions The efficacy and electrical parameters of HPBP is comparable with RVIP during the procedure and the short-term follow-up.

Right ventricular pacing: the best site is yet to be defined

The right ventricular (RV) apex is the traditional site to provide stable and reliable chronic ventricular pacing. Interest in alternate site pacing has grown since RV apical pacing has been associated with increased mortality and morbidity compared to normal atrio-ventricular conduction. 1-4 Alternate pacing sites include the RV septum and outflow tract.

Does Minimizing Ventricular Pacing Reduce the Incidence of Atrial Fibrillation ? A Systematic Review and Meta-analysis of Randomized Controlled Trials

Background:Right ventricular pacing disrupts atrioventricular synchrony and increases the risk of atrial fi brillation(AF).However,whether algorithms for minimizing ventricular pacing reduce the incidence of AF remains controversial.Therefore,we conducted a systematic review and meta-analysis to compare the incidence of AF between minimizing ventricular pacing and conventional pacing protocols in patients with pacemakers implanted.Methods:The PubMed,Embase,and Cochrane Library databases were searched up to August 1,2017,for randomized controlled trials that reported the incidence of AF in patients with and without the use of algorithms for minimizing ventricular pacing.Results:Eleven studies comprising 5705 participants(61%males,mean age 71 years[standard deviation 11 years])were fi nally included in the analysis.The mean follow-up duration was 24 months.Use of algorithms for minimizing ventricular pacing signifi cantly reduced the incidence of AF,with an odds ratio of 0.74(95%confi dence interval 0.55–1.00;P<0.05).There was moderate heterogeneity among studies(I 2=63%).Conclusions:The incidence of AF was reduced by 26%with use of algorithms for minimizing ventricular pacing.The incorporation of such algorithms in routine clinical practice should in theory lead to a decrease in AF-related morbidity and mortality.

The Prevalence and Short-Term Outcomes of Ventricular Dyssynchrony after Right Ventricular Pacing

Objective: Long-term right ventricular pacing has been associated with an increased risk of heart failure and cardiomyopathy. The pathophysiology of cardiomyopathy associated with right ventricular pacing remains unclear. We aim to evaluate the burden and short-term outcomes of ventricular dyssynchrony after immediate permanent pacemaker implantation. Materials and Methods: This prospective cohort study examined consecutive patients who had permanent pacemaker implantation at Vajira Hospital in 2019. Left ventricular systolic function, specifically left ventricular ejection fraction (LVEF) and echocardiographic ventricular dyssynchrony parameters were assessed. The endpoints included the prevalence of ventricular dyssynchrony, new-onset cardiomyopathy, heart failure, and death. The correlation between QRS complex duration, the burden of ventricular pacing, and echocardiographic ventricular dyssynchrony was measured. Results: Thirty-six consecutive patients underwent pacemaker implantation. The prevalence of mechanical ventricular dyssynchrony was 22.2% using the interventricular conduction delay method, 41.7% using LV pre-ejection period method, and 11.1% using the septal posterior wall motion abnormality method. Electrical ventricular dyssynchrony was 86.1% and new-onset cardiomyopathy was 17.1% after 3 months of permanent pacemaker implantation. The right ventricular pacing of more than 20% was significantly associated with cardiomyopathy (p < 0.022) and heart failure (log-rank, p = 0.049) within 3 months. But heart failure was not associated with mechanical ventricular dyssynchrony parameters (log-rank, p = 0.610;hazard ratio [HR], 1.53;95% confidence interval [CI], 0.29 - 7.96;p = 0.613 for IVMD and log-rank, p = 0.398;HR, 0.04;95% CI, 0.01 - 3316.7 for SPWMD). Conclusion: Mechanical and electrical ventricular dyssynchrony are common findings in right ventricular pacing. High-burden right ventricular pacing after 3 months of permanent pacemaker implantation is often associated with cardiomyopathy and heart failure, but mechanical and electrical ventricular dyssynchrony does not predict a short-term decline in left ventricular systolic function and heart failure.

Rapid right ventricular pacing for balloon valvuloplasty in congenital aortic stenosis:A systematic review

BACKGROUND Balloon aortic valvuloplasty(BAV)is a well-established treatment modality for congenital aortic valve stenosis.AIM To evaluate the role of rapid right ventricular pacing(RRVP)in balloon stabilization during BAV on aortic regurgitation(AR)in pediatric patients.METHODS A systematic review of the MEDLINE,Cochrane Library,and Scopus databases was conducted according to the PRISMA guidelines(end-of-search date:July 8,2020).The National Heart,Lung,and Blood Institute and Newcastle-Ottawa scales was utilized for quality assessment.RESULTS Five studies reporting on 72 patients were included.The studies investigated the use of RRVP-assisted BAV in infants(>1 mo)and older children,but not in neonates.Ten(13.9%)patients had a history of some type of aortic valve surgical or catheterization procedure.Before BAV,58(84.0%),7(10.1%),4(5.9%)patients had AR grade 0(none),1(trivial),2(mild),respectively.After BAV,34(49.3%),6(8.7%),26(37.7%),3(4.3%),patients had AR grade 0,1,2,and 3(moderate),respectively.No patient developed severe AR after RRVP.One(1.4%)developed ventricular fibrillation and was defibrillated successfully.No additional arrhythmias or complications occurred during RRVP.CONCLUSION RRVP can be safely used to achieve balloon stability during pediatric BAV,which could potentially decrease AR rates.

Transoesophageal emergency ventricular pacing with esophageal balloon electrode catheter

Objective To evaluate the safety and possibility of transesophageal emergency ventricular pacing with esophageal balloonelectrode catheter.Methods Sixty four patients with critical bradyarrhythmias were divided randomly to receive either transesophagealventricular pacing with esophageal balloon electrode catheter(balloon.catheter group,n=32),or transesophageai ventricular pacing withnormal esophageal electrode catheter(normal catheter group,n=32).Pulse width(ms),current output(mA),and the success rate werecompared between the 2 groups.Results Success rate in the balloon catheter group was 87.5%,which was significantly higher thanthat in the nodal catheter group(18.7%,X2=27.7,P＜0.01).The success rate oftransesophageal ventricular pacing with esophagealballoon electrode catheter was 87.5%.The average current output(mA)was significantly lower in the balloon catheter group than thatin the normal catheter group (24.5+2.5 mA VS 53±3.4mA,P＜0.05).Conclusions Esophageal balloon electrode catheter pacing couldbecome an available teclmiqBe for transesophageal emergency ventricular pacing.

希氏束起搏与右心室心尖部起搏对房室传导阻滞患者心脏结构学参数与功能学参数影响的临床研究

目的:探究希氏束起搏(HBP)与右心室心尖部起搏(RVAP)对房室传导阻滞(AVB)患者心脏结构学参数与功能学参数的影响。方法:选取收治的104例AVB患者为研究对象,随机分为HBP组和RVAP组各52例,HBP组行HBP治疗,RVAP组行RVAP治疗,比较两组术前、术后心脏结构学参数、心脏起搏参数、心率和血流动力学参数[心率(HR)、每搏输出量(SV)、心脏指数(CI)和左室射血分数(LVEF)]及QRS时限变化情况。结果:两组手术前后心脏结构学参数左心室收缩末期内径(LVESD)、左心室舒张末期内径(LVEDD)、室间隔厚度(IVS)、左室后壁厚度(LVPW)比较,差异均无统计学意义(均P>0.05);术中、术后1个月、术后6个月心脏起搏阈值、R波幅度、电极阻抗比较无统计学差异(均P>0.05);术前、术后1个月,两组HR、SV、CI、LVEF、QRS时限比较无统计学差异(均P>0.05);术后6个月,HBP组HR、SV、CI、LVEF显著高于RVAP组(均P<0.05),RVAP组QRS波时限显著低于HBP组(P<0.05);结论:HBP对AVB患者的电-机械同步性优于RVAP,近期心脏血流动力学及心功能稳定性良好。