Pacemaker-induced mitral regurgitation

Significant Mitral Regurgitation After Permanent Right Ventricular Pacemaker Implantation: Prognostic Implications

The underlying mechanisms leading to the development of mitral regurgitation (MR) after right ventricular (RV) pacemaker (PM) implantation and its prognostic value have yet to be fully understood. The purpose of this study was to evaluate the prevalence and clinical variables associated with the development of MR after RV pacing and its association with outcomes. A total of 451 patients (mean age 69 ± 15 years, 61% male) who underwent de novo RV PM implantation were included. The development of significant MR, defined as ≥moderate from mild or none/trace at baseline, occurred in 131 (29%) patients at a median of 2.4 years (interquartile range: 1.0 to 3.8 years) after PM implantation. Multivariate logistic regression analysis demonstrated that implantation of a single-chamber PM, left ventricular end-systolic volume index, and the presence of mild MR (vs no MR) at baseline were independently associated with the development of significant MR post-implant. Cardiac events, defined as the composite of all-cause mortality or heart failure hospitalization, occurred in 143 patients (31.7%) during a median follow-up of 5.4 years (interquartile range: 3.0 to 8.1 years). Multivariate Cox regression analysis demonstrated that the development of significant MR was independently related to the occurrence of cardiac events. In conclusion, the development of significant MR after PM implantation is seen in about one-third of recipients and is independently associated with adverse cardiac events.

Torrential mitral regurgitation following right ventricular apical pacing in rheumatic mitral valve disease: a case report

Background

Mitral regurgitation may develop or worsen following right ventricular apical pacing due to dyssynchronous left ventricular contraction. Pre-existing secondary mitral annular dilation is a well-recognized and important contributing factor. This description of pacing-induced torrential mitral regurgitation in the setting of rheumatic mitral valve disease is a rare case in which a primary mitral valve lesion was the antecedent mechanism.

Case summary

A 60-year-old man was admitted with dizziness and pre-syncope. Twelve-lead electrocardiogram showed complete heart block. A dual-chamber pacemaker was implanted and programmed in DDD mode. Transthoracic echocardiography performed a day later demonstrated a left ventricular ejection fraction (LVEF) of 63% and moderate mitral regurgitation. The patient presented 4 months later with breathlessness and orthopnoea. Pacemaker interrogation demonstrated a 98% right ventricular pacing burden. Echocardiography revealed torrential mitral regurgitation secondary to left ventricular dyssynchrony and complete loss of leaflet coaptation with preserved systolic function. Post-capillary pulmonary hypertension was diagnosed following right heart catheterization. The patient underwent metallic mitral valve replacement, tricuspid annuloplasty, and left internal mammary artery grafting to the left anterior descending artery for a severe proximal stenosis. On inspection, the native mitral valve was notably rheumatic in appearance, and this was confirmed histologically.

Discussion

It is important to closely monitor the progression of mitral regurgitation in those with primary mitral valve disease undergoing right ventricular pacing. Early follow-up may prevent the adverse haemodynamic consequences of worsening mitral regurgitation, with a greater chance of recovery of left ventricular function following surgery.

Impact of pacing mode and different echocardiographic parameters on cardiac output (PADIAC)

Introduction

The extent of the hemodynamic benefit from AV-synchronous pacing in patients with sinus rhythm and AV block is not completely understood. Thus, we systematically investigated the association of an array of echocardiographic and epidemiological parameters with the change in cardiac output depending on the stimulation mode (AV-synchronous or AV-asynchronous pacing).

Methods

Patients in sinus rhythm after previous dual chamber pacemaker implantation underwent a thorough basic echocardiographic assessment of diastolic and systolic left ventricular function, and atrial function (26 echo parameters, including novel speckle tracking strain measurements). Then, stroke volume was measured with AV-synchronous (DDD) and AV-asynchronous (VVI) pacing. Each patient represented their own control, and the sequence of stroke volume measurements was randomized.

Results

In this prospective single-center study (NCT04068233, registration August 22nd 2019), we recruited 40 individuals. The stroke volume was higher in all patients when applying AV-synchronous DDD pacing [median increase 12.8 ml (16.9%), P < 0.001]. No echo parameter under investigation was associated with the extent of stroke volume increase in a linear regression model. Of all epidemiological variables, a history of acute myocardial infarction (AMI) was associated with an attenuated stroke volume gain in a univariate and a multivariate regression model that adjusted for confounders. A- and S-wave velocities were reduced in the AMI group.

Discussion

In our cohort of patients, each subject benefited from AV-synchronous DDD pacing. No single echo parameter could predict the amount of stroke volume increase. The beneficial effect of AV-synchronous pacing on stroke volume was attenuated after prior acute myocardial infarction.ClinicalTrials.gov identifier (NCT number): NCT04068233.

Does Pacemaker Implantation After Surgical Aortic Valve Replacement Impact Long-Term Morbidity and Mortality? A Focused Review

Permanent pacing remains a serious complication that can occur in the postoperative period of surgical aortic valve replacement. The reported incidence is variable, and there are many perioperative factors that have been linked with a greater need for permanent pacing. Permanent pacing can also be associated with late lead-related and cardiac complications that can affect late outcome. However, the degree of late dependence on pacemakers is varied, and some studies have shown that a substantial proportion of patients do not need long-term pacing. Some groups have found that permanent pacing was associated with a negative impact on long-term survival in these patients. A common finding among these studies is that the groups of patients with pacemakers had higher preoperative surgical risk and comorbidity status. This makes it difficult to establish whether permanent pacing on its own represents a risk factor for late mortality or whether it is simply a marker that reflects the higher complexity and comorbidities in this group of patients.

Brady-arrhythmias in patients with atrial fibrillation and heart failure of reduced ejection fraction: is his-bundle pacing superior to biventricular pacing？

OBJECTIVE

To investigate the efficacy and safety of His-bundle pacing (HBP) compared with the traditional biventricular pacing (BVP) on patients with brady-arrhythmias, who suffer from permanent atrial fibrillation (AF) and heart failure with reduced ejection fraction (HFrEF).

METHODS

All patients with brady-arrhythmias, permanent AF and HFrEF were continuously enrolled from January 2017 to July 2019 and followed up for at least 12 months. The differences in QRS duration (QRSd), New York Heart Association (NYHA) classification, left ventricular ejection fraction (LVEF), tricuspid regurgitation grade, mitral regurgitation grade, left ventricular end-diastolic diameter (LVEDD), and left atrial size were compared.

RESULTS

A total of 52 patients were enrolled: 37 patients were with HBP and 15 patients with BVP. There was no electrode dislodged, perforation, infection or thrombosis during the follow-up of 18.12 ± 4.45 months. The success rate for HBP implantation was 88.10%. The capture threshold of his-bundle and the threshold of the left ventricular lead remained stable during follow-up. LVEF increased to higher than 50% in 11 patients with HBP (29.73%). The NYHA classification (both p < .001), LVEF (both p < .001) and LVEDD improved significantly during the follow-up in both groups. NYHA (p = .030), LVEF (p = .013), and LVEDD (p = .003) improved in patients with HBP compared with BVP.

CONCLUSION

HBP was safe and more effective in improving the cardiac function and remodeling in patients with brady-arrhythmias, permanent AF and HFrEF compared with BVP.

A Case of Severe Mitral Valve Regurgitation in a Patient with Leadless Pacemaker

An 85-year-old man with cardiac history notable for atrial fibrillation diagnosed 10 years ago which was being treated with atenolol and warfarin presented to our institution with persistent atrial fibrillation. His echocardiogram showed ejection fraction (EF) of 56%, no regional wall motion abnormalities, mild mitral and pulmonary regurgitation, and trivial tricuspid regurgitation. Despite this treatment, he had recurrent episodes of paroxysmal symptomatic atrial fibrillation with a rapid rate requiring multiple emergency department visits and hospital admissions. Given difficulty to control the rate, he underwent atrioventricular (AV) nodal ablation and leadless pacemaker insertion. Fifteen days after the procedure, he was found to have a severe mitral regurgitation murmur.

Permanent HIS bundle Pacing Feasibility in Routine Clinical Practice: Experience from an Indian Center

There is a paucity of experience regarding His bundle pacing (HBP) at laboratories initially attempting the procedure, especially in the Indian scenario. Patient who underwent HBP were selected for pacing therapy or in lieu of cardiac resynchronization therapy (CRT) at a single center. Among 22 patients attempted, 19 patients underwent successful implant, achieving selective HBP in 14 patients. There was a significant improvement in left ventricular ejection fraction (LVEF) (49.3 ± 9.3 vs. 36.7 ± 9.2) in the LV dysfunction subgroup (n = 6). Over a follow-up of 15 ± 6.5 months, thresholds were stable in all except one patient, and there was no requirement of lead revision. In summary, we found that HBP is a feasible option for achieving physiological pacing.

Adverse Consequences of Right Ventricular Apical Pacing and Novel Strategies to Optimize Left Ventricular Systolic and Diastolic Function

Several studies have focused on the deleterious consequences of Right Ventricular Apical (RVA) pacing on Left Ventricular (LV) function, mediated by pacing-induced ventricular dyssyn-chrony. Therapeutic strategies to reduce the detrimental consequences of RVA pacing have been pro-posed, that includes upgrading of RVA pacing to Cardiac Resynchronization Therapy (CRT), alterna-tive Right Ventricular (RV) pacing sites, minimal ventricular pacing strategies, as well as atrial-based pacing. In developing countries, single chamber RV pacing still constitutes a majority of cases of permanent pacing, and assessment of the optimal RV pacing site is of paramount importance. In chronically-paced patients, it is crucial to maintain as close and normal LV physiological function as possible, by minimizing ventricular dyssynchrony, reducing the chances for heart failure and other complications to develop. This review provides an analysis of the deleterious immediate and long-term consequences of RVA pacing, and the most recent available evidence regarding improvements in pacing options and strategies to optimize LV diastolic and systolic function. Furthermore, the place of advanced echocardiography in the identification of patients with pacing-induced LV dysfunction, the potential role of a new predictor of LV dysfunction in RV-paced subjects, and the long- term out-comes of patients with RV septal pacing will be explored

Chronic Right Ventricular Pacing in the Heart Failure Population

Purpose of Review

We review the trials that have demonstrated potentially harmful effects from right ventricular (RV) apical pacing as well as reviewing the evidence of alternative RV pacing sites and cardiac resynchronization therapy (CRT) for patients who have heart failure and atrioventricular (AV) block.

Recent Findings

The role of CRT in patients with AV block and impaired left ventricular function remains an important consideration. The BLOCK HF trial demonstrated better outcomes with CRT pacing over RV pacing in patients with left ventricular systolic dysfunction (LVSD) and AV block who were expected to have a high RV pacing burden, but failed to demonstrate a mortality benefit.

Summary

CRT seems to have a beneficial effect on left ventricular reverse remodeling, systolic function, and clinical outcomes in patients with New York Heart Association (NYHA) functional class I–III heart failure, moderate to severe LVSD, and AV block compared to RV pacing. However, it is less clear whether there is a similar benefit from CRT in patients with a high percentage of RV pacing who have normal or mild LVSD in the treatment of AV block.

Honing in on optimal ventricular pacing sites: an argument for his bundle pacing

OPINION STATEMENT

Frequent ventricular pacing is often or completely unavoidable in patients with high-grade or complete heart block. Over time, patients with high-burden RV pacing are at risk for developing symptomatic cardiomyopathy due to pacing-induced ventricular dyssynchrony. Growing awareness of this concern has generated interest in alternative pacing sites like the septum and outflow tract, the thinking being that these sites will more closely mimic His-Purkinje-mediated ventricular activation. Numerous studies have met with mixed results likely due to the fact that-to quote Marvin Gaye-there ain't nothing like the real thing. Herein lies the advantage of His bundle pacing (HBP), as it is the only pacing modality capable of physiological ventricular activation. HBP has been demonstrated to be safe and reliable in various forms of AV block with minimal drawbacks, namely modestly higher pacing thresholds when compared with other RV sites. Additionally, HBP is a truly physiologic alternative to biventricular pacing to effect cardiac resynchronization therapy (CRT), a concept supported by small observational and prospective studies. In our view, His bundle pacing should be considered in nearly all patients requiring ventricular pacing.

The role of biventricular pacing in the prevention and therapy of pacemaker-induced cardiomyopathy

Right ventricular (RV) pacing produces well-known long-term deleterious effects not only on already compromised, but also on the normal left ventricle (LV). The activation pattern mimicks that of left bundle branch block, with delayed activation of the LV free wall, and results in electrical and mechanical dyssynchrony. Long-term mandatory (100%) RV pacing, increases LV dimensions and decreases the ejection fraction. Many of these negative effects of pacing can be overcome by biventricular pacing. In this review, we describe the characteristics of pacemaker-induced cardiomyopathy, its incidence, and the use of cardiac resynchronization therapy (CRT) for its therapy and prevention. The gaps in the current organizational guidelines for using CRT in the treatment of bradycardia are identified, and goals for future research are discussed.

Cardiomyopathy induced by artificial cardiac pacing: myth or reality sustained by evidence?

Implantable cardiac pacing systems are a safe and effective treatment for symptomatic irreversible bradycardia. Under the proper indications, cardiac pacing might bring significant clinical benefit. Evidences from literature state that the action of the artificial pacing system, mainly when the ventricular lead is located at the apex of the right ventricle, produces negative effects to cardiac structure (remodeling, dilatation) and function (dissinchrony). Patients with previously compromised left ventricular function would benefit the least with conventional right ventricle apical pacing, and are exposed to the risk of developing higher incidence of morbidity and mortality for heart failure. However, after almost 6 decades of cardiac pacing, just a reduced portion of patients in general would develop these alterations. In this context, there are not completely clear some issues related to cardiac pacing and the development of this cardiomyopathy. Causality relationships among QRS widening with a left bundle branch block morphology, contractility alterations within the left ventricle, and certain substrates or clinical (previous systolic dysfunction, structural heart disease, time from implant) or electrical conditions (QRS duration, percentage of ventricular stimulation) are still subjecte of debate. This review analyses contemporary data regarding this new entity, and discusses alternatives of how to use cardiac pacing in this context, emphasizing cardiac resynchronization therapy.

Chronic right ventricular apical pacing: adverse effects and current therapeutic strategies to minimize them

The permanent cardiac pacemaker is the only effective therapy for patients with symptomatic bradycardia and hundreds of millions are implanted worldwide every year. Despite its undisputed clinical benefits, the last two decades have drawn much attention to the negative effects associated with long-term pacing of the right ventricle (RV). Experimental and clinical studies have shown that RV pacing produces ventricular dyssynchrony, similar to that of left bundle branch block, with consequent detrimental effects on cardiac structure and function, with adverse clinical outcomes such as atrial fibrillation, heart failure and death. Although clinical evidence largely comes from subanalyses of pacemaker and implantable cardiac defibrillator studies, there is strong evidence that patients with reduced left ventricular function are at high risk of suffering from the detrimental effects of long-term RV pacing. Biventricular pacing in cardiac resynchronization therapy devices can prevent ventricular dyssynchrony and has emerged as an attractive option in this patient group with promising results and more clinical studies underway. Moreover, there is evidence that specific pacemaker algorithms that minimize RV pacing can reduce the negative effects of RV stimulation on cardiac function and may also prevent clinical deterioration. The extent of the long-term clinical effects of RV pacing in patients with normal ventricular function and how to prevent this are less clear and subject to future investigation.

Permanent His-bundle pacing maintains long-term ventricular synchrony and left ventricular performance, unlike conventional right ventricular apical pacing

AIMS

Right ventricular apical pacing (RVAP) may be deleterious, determining abnormal left ventricular (LV) electrical activation and progressive LV dysfunction. Permanent His-bundle pacing (HBP) has been proposed to prevent this detrimental effect. The aim of our study was to compare the long-term effects of HBP on LV synchrony and systolic performance with those of RVAP in the same group of patients.

METHODS

Our analysis included 26 patients who received both an HBP lead and an RVAP lead, as backup, in our electrophysiology laboratory between 2004 and 2007. After implantation, all devices were programmed to obtain HBP. An intra-patient comparison of the effects of HBP and RVAP on LV dyssynchrony and function was performed at the last available follow-up examination.

RESULTS

After a mean of 34.6 ± 11 months, the pacing modality was temporarily switched to RVAP. During RVAP, LV ejection fraction significantly decreased (50.1 ± 8.8% vs. 57.3 ± 8.5%, P < 0.001), mitral regurgitation significantly increased (22.5 ± 10.9% vs.16.3 ± 12.4%; P = 0.018), and inter-ventricular delay significantly worsened (33.4 ± 19.5 ms vs. 7.1 ± 4.7 ms, P = 0.003) in comparison with HBP. However, the myocardial performance index was not statistically different between the two pacing modalities (P = 0.779). No asynchrony was revealed by tissue Doppler imaging during HBP, while during RVAP the asynchrony index was significantly higher in both the four-chamber (125.8 ± 63.9 ms; P = 0.035 vs. HBP) and two-chamber (126 ± 86.5 ms; P = 0.037 vs. HBP) apical views.

CONCLUSION

His-bundle pacing has long-term positive effects on inter- and intra-ventricular synchrony and ventricular contractile performance in comparison with RVAP. It prevents asynchronous pacing-induced LV ejection fraction depression and mitral regurgitation.

The downside of right ventricular apical pacing

The right ventricular (RV) apex has been the standard pacing site since the development of implantable pacemaker technology. Although RV pacing was initially only utilized for the treatment of severe bradyarrhythmias usually due to complete heart block, today the indications for and implantation of RV pacing devices is dramatically larger. Recently, the adverse effects of chronic RV apical pacing have been described including an increased risk of heart failure and death. This review details the detrimental effects of RV apical pacing and their shared hemodynamic pathophysiology. In particular, the role of RV apical pacing induced ventricular dyssynchrony is highlighted with a specific focus on differential outcome based upon QRS morphology at implant.

Impact of right ventricular apical pacing and its frequency on left atrial function

Background

Right ventricular apical (RVA) pacing induces left ventricular (LV) dyssynchrony, increases the risk of persistent atrial fibrillation in the long term. The aim was to investigate the effects of RVA pacing on left atrial (LA) function, which are unknown.

Methods

Echocardiographic evaluation including LV dyssynchrony based on conventional Doppler, tissue Doppler imaging and speckle tracking strain echocardiography was done before and after (12 months) single-chamber ventricular pacemaker implantation in 40 patients with sick sinus syndrome. Patients were divided to 2 groups, according to the RVA pacing frequency (group I had higher pacing rate of more than 50% and group II, less than 50%).

Results

There was no significant difference in LV ejection fraction, however, mean global LV strain, myocardial performance index, and parameters of LV dyssynchrony had shown significant changes after 12 months of RVA pacing. There were also significant increase in the LA volume index and the reduction of peak systolic LA strain and strain rate (SR), peak early and late diastolic SR after RVA pacing. Moreover, there was significant deterioration of LV dyssynchrony and both LA and LV longitudinal function in even group II. LA functional deterioration and LA volume was significantly correlated with the frequency of RVA pacing.

Conclusion

LV dyssynchrony, induced by RVA pacing, significantly impaired active LA contraction and passive stretching, and these findings were shown in the patients with even less than 50% of RVA pacing. Impairment of LA strain/SR was significantly correlated with the frequency of RVA pacing.

Permanent His-bundle pacing: seeking physiological ventricular pacing

AIMS

Right ventricular apical pacing can have deleterious effects and the His bundle has been widely reported to be an alternative site. This paper presents our experience with permanent His-bundle pacing (HBP).

METHODS AND RESULTS

Patients referred for pacemaker implants (regardless of block type) were screened to determine if temporary HBP corrected conduction dysfunctions (threshold < or =2.5 V for 1 ms) and provided infra-Hisian 1:1 conduction of at least 120 s/m. Of the 182 patients selected, HBP corrected conduction dysfunctions in 133 (73%) patients, 42 (32%) of whom were rejected for the permanent procedure due to high thresholds. His-bundle lead implantation was attempted in the remaining 91 patients and was successful in 59 (65% of all attempts, 44% of all possible cases).

CONCLUSION

In some patients, permanent HBP may be an alternative to right ventricular apical pacing.

The effects of right ventricular apical pacing on ventricular function and dyssynchrony implications for therapy

Cardiac pacing is the only effective treatment for patients with sick sinus syndrome and atrioventricular conduction disorders. In cardiac pacing, the endocardial pacing lead is typically positioned at the right ventricular (RV) apex. At the same time, there is increasing indirect evidence, derived from large pacing mode selection trials and observational studies, that conventional RV apical pacing may have detrimental effects on cardiac structure and left ventricular function, which are associated with the development of heart failure. These detrimental effects may be related to the abnormal electrical and mechanical activation pattern of the ventricles (or ventricular dyssynchrony) caused by RV apical pacing. Still, it remains uncertain if the deterioration of left ventricular function as noted in a proportion of patients receiving RV apical pacing is directly related to acutely induced left ventricular dyssynchrony. The upgrade from RV pacing to cardiac resynchronization therapy may partially reverse the deleterious effects of RV pacing. It has even been suggested that selected patients with a conventional pacemaker indication should receive cardiac resynchronization therapy to avoid the deleterious effects. This review will provide a contemporary overview of the available evidence on the detrimental effects of RV apical pacing. Furthermore, the available alternatives for patients with a standard pacemaker indication will be discussed. In particular, the role of cardiac resynchronization therapy and alternative RV pacing sites in these patients will be reviewed.

Effect of right ventricular apical pacing in survivors of myocardial infarction

BACKGROUND

Much information is available regarding the possible negative effects of long-term right ventricular (RV) apical pacing, which may cause worsening of heart failure. However, very limited data are available regarding the effects of RV pacing in patients with a previous myocardial infarction (MI).

METHODS AND RESULTS

We screened 115 consecutive post-MI patients and matched a group of 29 pacemaker (PM) recipients with a group of 49 unpaced patients, for age, left ventricular (LV) ejection fraction, and site of MI. During a median follow-up of 54 months, echocardiograms showed a decrease in LV ejection fraction in the paced group, from 51 +/- 10 to 39 +/- 11 (P < 0.01), and a minimal change in the unpaced group, from 57 +/- 8 to 56 +/- 7 (P = 0.98). Similar change was observed in systolic and diastolic diameters and volumes.

CONCLUSIONS

The study showed that, in post-MI patients, RV apical pacing was associated with a worsening of LV function, suggesting that, among MI survivors, the need for a PM is a marker of worse outcome.

Mitral valve regurgitation and left ventricular systolic dysfunction: corrective surgery or cardiac resynchronization therapy?

Mitral regurgitation (MR) can be found in a sizeable percentage of patients with chronic congestive heart failure (CHF) and systolic left ventricular (LV) dysfunction despite a structurally normal valve. This functional or secondary regurgitation results from a dysbalance between closing and opening forces on the mitral leaflets due to reduced LV contractility, geometric distortion of the subvalvular apparatus, and global dilatation of the left ventricle and the mitral annulus. MR in LV dysfunction has a negative impact on both symptoms and prognosis. Surgical correction of secondary MR remained controversial although it was found to be technically feasible and to provide symptomatic benefit in some (mostly) mono-center series. Cardiac resynchronization therapy (CRT) was also found to improve secondary mitral regurgitation. However, the prediction in which patient significant secondary MR will improve with CRT is largely unresolved. The following paper reviews the available data concerning the two major interventional options for significant secondary MR in patients with CHF and systolic LV dysfunction, i.e. mitral valve surgery vs. CRT, and describes our institutional approach to this problem.

Permanent direct his bundle pacing does not induce ventricular dyssynchrony unlike conventional right ventricular apical pacing. An intrapatient acute comparison study

BACKGROUND

Benefits of A-V synchrony during right ventricular apical pacing are neutralized by induction of ventricular dyssynchrony. Only a few data are reported about direct His bundle pacing influence on ventricular synchronism.

AIM

Was to assess the capability of direct His bundle pacing to prevent pacing-induced ventricular dyssynchrony comparing DDD- (or VVI- in case of Atrial Fibrillation) right ventricular apical pacing with DDD- (or VVI-) direct His bundle pacing in the same patients cohort.

METHODS

23 of 24 patients (mean age 75.1 +/- 6.4 years) with narrow QRS (HV < 65 ms) underwent permanent direct His bundle pacing for "brady-tachy syndrome" (11) or supra-Hisian II/III-degree AV Block (permanent atrial fibrillation 7, AV Node ablation 1). A 4.1 F screw-in lead was fixed in His position, guided by endocardial pacemapping and unipolar recordings. Additional permanent (13 patients) or temporary right ventricular apical pacing leads were also positioned. Inter- and left intra-ventricular dyssynchrony, mitral regurgitation and left systolic ventricular function Tei index were assessed during either direct His bundle pacing or right ventricular apical pacing.

RESULTS

Permanent direct His bundle pacing was obtained in 23 of 24 patients. Indexes of ventricular dyssynchrony were drastically reduced, mitral regurgitation decreased and left systolic ventricular function Tei index improved during direct His bundle pacing (or His bundle and septum pacing) in comparison to apical pacing (p < 0.05). No statistically significant differences were observed between direct His bundle pacing and combined His bundle and septum pacing.

CONCLUSION

Direct His bundle pacing (also fused with adjacent septum capture) prevents pacing-induced ventricular dyssynchrony.