His Bundle Pacing

Beneficial effects of upgrading to His-Purkinje system pacing in patients with pacing-induced cardiomyopathy: a systematic review and meta-analysis

Background

The purpose of this study was to evaluate the effectiveness of His-Purkinje system pacing (HPSP) in the management of patients with pace-induced cardiomyopathy (PICM).

Methods

PubMed, Embase, Web of Science, and the Cochrane Library were searched comprehensively to collect related studies published from the inception of databases to June 1, 2022. R 4.04 software, including the Metafor package, matrix package, and the Meta package, was utilized to conduct the singe-arm meta-analysis. The methodology index for non-randomized studies (MINORS) was used to assess the methodological quality of the included studies.

Results

A total of seven studies were included, involving 164 PICM patients. The meta-analysis showed that HPSP ameliorated the left ventricular ejection fraction (LVEF) by 13.41% (95% CI [11.21-15.61]), improved the New York Heart Association (NYHA) classification by 1.02 (95% CI [-1.41 to -0.63]), and shortened the QRS duration (QRSd) by 60.85 ms (95% CI [-63.94 to -57.75]), resulting in improved cardiac functions in PICM patients. Besides, HPSP reversed the ventricular remodeling, with a 32.46 ml (95% CI [-53.18 to -11.75]) decrease in left ventricular end systolic volume (LVESV) and a 5.93 mm (95% CI [-7.68 to -4.19]) decrease in left ventricular end-diastolic dimension (LVEDD). HPSP also showed stable electrical parameters of pacemakers, with a 0.07 V (95% CI [0.01-0.13]) increase in pacing threshold, a 0.02 mV (95% CI [-0.85 to 0.90]) increase in sensed R-wave amplitude, and a 31.12 Ω reduction in impedance (95% CI [-69.62 to 7.39]). Compared with LBBP, HBP improved LVEF by 13.28% (95% CI [-11.64 to 14.92]) vs 14.43% (95% CI [-13.01 to 15.85]), ameliorated NHYA classification by 1.18 (95% CI [-1.97 to -0.39]) vs 0.95 (95% CI [-1.33 to -0.58]), shortened QRSd by 63.16 ms (95% CI [-67.00 to -59.32]) vs 57.98 ms (95% CI [-62.52 to -53.25]), and decreased LVEDD by 4.12 mm (95% CI [-5.79 to -2.45]) vs 6.26 mm (95% CI [-62.52 to -53.25]). The electrical parameters of the pacemaker were stable in both groups.

Conclusions

This meta-analysis showed that HPSP could significantly improve cardiac function, promote reverse remodeling, and provide stable electrical parameters of pacemakers for PICM patients.

Comparison of cardiac function between left bundle branch pacing and right ventricular outflow tract septal pacing in the short-term: A registered controlled clinical trial

BACKGROUND

The novel method of left bundle branch pacing (LBBP) has been reported to produce a narrower QRS duration and lower pacing threshold than right ventricular outflow tract septal pacing (RVOP). However, whether LBBP is superior to traditional RVOP in improving cardiac function still lacks sufficient evidence.

OBJECTIVE

The purpose of this study was to compare the changes in cardiac function (especially in brain natriuretic peptide (BNP)levels, left atrial function, and left ventricular diastolic function) within 7 days between LBBP and RVOP.

METHODS AND RESULTS

A single-centre prospective controlled registered clinical study was conducted with 84 patients with bradycardia indications. Forty-two patients underwent RVOP, and 42 patients underwent LBBP. The pacemaker parameters were adjusted so that the ventricular ratio was over 90% and rate was 60-70 bpm. The changes in BNP levels and echocardiogram and speckle-tracking echocardiagraphy findings were compared between the two groups before and within 7 days after implantation: (1) BNP: there was no significant difference in BNP level between the two groups before and 1 day after implantation, while the LBBP group had significantly lower levels than the RVOP group on day 7 [(65.15 ± 56.96)pg/ml vs.(129.82 ± 101.92)pg/ml, P < 0.001]. (2) Cardiac echocardiography: the e' value of the LBBP group was higher than that of the RVOP group 7 days after implantation[(6.39 ± 2.65) cm/s vs. (5.45 ± 1.35)cm/s, P = 0.049]. The E/e' and peak E-wave velocity in the LBBP group decreased significantly after 7 days [16.57 ± 6.55 vs. 12.75 ± 5.16 P = 0.043, (88.6 ± 24.37)cm/s vs. (75.68 ± 28.10)cm/s P = 0.030]; in contrast, there were no significant changes in the RVOP group [14.13 ± 3.85 vs.14.10 ± 4.85 P = 0.50, (77.33 ± 21.14)cm/s vs. (74.45 ± 23.03)cm/s P = 0.56). (3)Speckle-tracking echocardiagraphy: there was no significant difference in left atrial strain or the strain rate between the LBBP and RVOP groups，but the absolute values of left atrial strain and strain rate in the LBBP group increased, while those in the RVOP group decreased.

CONCLUSION

This study demonstrates that compared to RVOP, LBBP can increase left ventricular early diastolic function, improve BNP levels, and has a tendency to increase left atrial myocardial elasticity and left atrial strain capacity in the short term in pacemaker-dependent patients.

[Echocardiographic assessment of myocardial function during His bundle and right ventricular pacing]

INTRODUCTION

In patients with pacemaker (PM) therapy, His bundle stimulation (HBS) may lead to a more synchronous activation of the left ventricle (LV) than conventional right ventricular stimulation (RVS). In this study, we investigated to which extent this effect can be objectified by means of contemporary echocardiographic functional imaging.

METHODS

In all, 15 RVS patients (6 women, mean age 76.6 ± 4.1 years) and 15 HBS patients (6 women, mean age 74.6 ± 3.7 years) underwent echocardiography with and without cardiac pacing. Besides LV end-diastolic volume (EDV), ejection fraction (EF), and global strain (GLS), we measured global and regional myocardial work and LV efficiency based on noninvasive pressure-strain loops.

RESULTS

In all HBS patients, optimization of PM settings resulted in immediate changes in myocardial function parameters. With pacing, RVS patients showed a higher decrease in EF and GLS than HBS patients. Global LV work and LV work efficiency decreased significantly only in RVS patients.

CONCLUSION

Changes in regional and global myocardial function can by proven and quantified by functional echocardiography. In patients under PM therapy, HBS shows functional advantages in comparison to conventional RVS.

Novel Method for Assessment of His Bundle Pacing Morphology Using Near Field and Far Field Device Electrograms

BACKGROUND

The 12-lead ECG is considered the gold standard to differentiate between selective (S), nonselective (NS) His bundle pacing (HBP), and right ventricular septal capture in routine clinical practice. We sought to assess the utility of device EGM recordings as a tool to identify the type of HBP morphology.

METHODS

One hundred forty-eight consecutive patients underwent HBP with a 3830 Select Secure lead (Medtronic, Inc) at 3 centers between October 2016 and October 2017. The near field V-EGM morphology (NF EGM), near field V-EGM time to peak (NF_{Time to peak}), and far-field EGM QRS duration (QRSd) were recorded while pacing the His lead with simultaneous 12-lead ECG rhythm strips.

RESULTS

Indications for HBP were sinus node dysfunction, atrioventricular conduction disease, and cardiac resynchronization therapy in 68 (46%), 56 (38%), and 24 (16%) patients, respectively. Baseline QRSd was 108±38 ms with QRSd >120 ms in 57 (39%) patients (27 right bundle branch block, 18 left bundle branch block, and 12 intraventricular conduction delay). S-HBP was noted in 54 (36%) patients. A positive NF_EGM and NF_{Time to peak} >40 ms were highly sensitive (94% and 93%, respectively) and specific (90% and 94%) for S-HBP irrespective of baseline QRSd. All 3 parameters (+NF_EGM, NF_{Time to peak} >40 ms, and far-field EGM QRSd <120 ms) had high negative predictive value (97%, 95%, and 92%). A novel device-based algorithm for S-HBP was proposed. EGM transitions correlated with ECG transitions during threshold testing and can help accurately differentiate between S-HBP, NS-HBP, and right ventricular septal pacing with a cumulative positive predictive value of 91% (positive predictive value =100% in patients with baseline QRSd <120 ms).

CONCLUSIONS

We propose a novel and simple criteria for accurate differentiation between S-HBP, NS-HBP, and right ventricular septal capture morphologies by careful analysis of device EGMs alone. This study paves the way for future studies to assess autocapture algorithms for devices with HBP.

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