Effect of Right Ventricular Apex Pacing on the Tei Index and Brain Natriuretic Peptide in Patients with a Dual-Chamber Pacemaker

Clinical impact of left bundle branch area pacing in heart failure with preserved ejection fraction and mid-range ejection fraction

BACKGROUND

Recently, conduction system pacing, including His bundle and left bundle branch area pacing (LBBAP), has emerged as an alternative pacing procedure for right ventricular (RV) pacing. The current study aimed to compare the clinical outcomes of LBBAP and conventional RV mid-septal pacing (RVMSP) in patients with heart failure (HF) with preserved ejection fraction (HFpEF) and HF with mid-range ejection (HFmrEF) requiring frequency RV pacing due to atrioventricular block (AVB).

METHODS

A total of 89 patients with HFpEF and HFmrEF requiring RV pacing due to symptomatic AVB were enrolled between September 2018 and April 2021, among whom 43 and 46 underwent LBBAP and RVMSP, respectively.

RESULTS

No significant differences in baseline characteristics were observed between the two groups. The LBBAP group had a significantly shorter paced-QRS duration and paced left ventricular activation time (LVAT) compared to the RVMSP group (123.4 ± 10.4 ms vs. 152.3 ± 12.3 ms, p < 0.001 and 68.3 ± 10.0 ms vs. 95.2 ± 12.3 ms, p < 0.001, respectively). The LBBAP group had significantly lower N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels at the 6-month follow-up compared to the RVMSP group [459.6 pg/mL (240.4-678.7) vs. 972.7 pg/mL (629.5-1315.9), p = 0.01]. More patients in the LBBAP group exhibited a significant improvement in NT-proBNP, defined as a >50% decreased from baseline levels.

CONCLUSION

LBBAP maintains physiological ventricular activation and contributes to greater improvement in NT-proBNP value 6 months after implantation in patients with HFpEF and HFmrEF compared to RVMSP. This article is protected by copyright. All rights reserved.

Pacemaker Induced Cardiomyopathy: An Overview of Current Literature

Pacemaker induced cardiomyopathy (PICM) is commonly defined as a reduction in left ventricular (LV) function in the setting of right ventricular (RV) pacing. This condition may be associated with the onset of clinical heart failure in those affected. Recent studies have focused on potential methods of identifying patients at risk of this condition, in addition to hypothesizing the most efficacious ways to manage these patients. Newer pacing options, such as His bundle pacing, may avoid the onset of PICM entirely.

Effects of long-term right ventricular apex pacing on left ventricular dyssynchrony, morphology and systolic function

BACKGROUND

Right ventricular apex (RVA) is still the most common implanted site in the world. There are a large number of RVA pacing population who have been carrying dual-chamber permanent pacemaker (PPM) over decades. Comparison of left ventricular dyssynchrony, morphology and systolic function between RVA pacing population and healthy population is unknown.

METHOD

This case-control study enrolled 61 patients suffered from complete atrioventricular block (III°AVB) for replacement of dual-chamber PPM. Then, 61 healthy controls matched with PPM patients in gender, age, follow-up duration and complications were included. The lead impedance, pacing threshold and sensing were compared between at implantation and long-term follow-up. Left ventricular (LV) dyssynchrony, morphology and systolic function were compared between RVA pacing population (RVA group) and healthy population (healthy group) at implantation (baseline) and follow-up. And clarify the predictors of LV systolic function in RVA group at follow-up.

RESULTS

After 112.44 ± 34.94 months of follow-up, comparing with parameters at implantation, atrial lead impedance decreased significantly (690 ± 2397 Ω vs 613 ± 2257 Ω， p = 0.048); atrial pacing threshold has a increased trend and P-wave amplitude has a decreased trend, but there was no statistical differences; while, RVA ventricular lead threshold increased significantly (0.50 ± 0.23 V vs 0.91 ± 0.47 V， p < 0.001), impedance (902 ± 397 Ω vs 680 ± 257 Ω，p < 0.001) and R-wave amplitude (11.71 ± 9.40mv vs 7.00 ± 6.91 mv， p < 0.001) decreased significantly. Compared with healthy group, long-term RVA pacing significantly increased ventricular dyssynchrony (mean QRS duration, 156.21 ± 29.80 ms vs 97.08 ± 15.70 ms， p < 0.001), left atrium diameter (LAD, 40.61 ± 6.15 mm vs 37.49 ± 4.80 mm，p = 0.002), left ventricular end-diastolic diameter (LVEDD, 49.15 ± 5.93 mm vs 46.41 ± 3.80 mm，p = 0.003), left ventricular hypertrophy (LVMI, 121.86 ± 41.52 g/m2 vs 98.41 ± 25.29 g/m2，p < 0.001), significantly deteriorated degree of tricuspid regurgitation (p < 0.001), and significantly decreased left ventricular ejection fraction (LVEF, 61.38 ± 8.10% vs 64.64 ± 5.85%, p = 0.012), but after long-term RVA pacing, the mean LVEF was still more than 50%. Long-term RVA group LVEF was negatively correlated with preimplantation LVMI (B = -0.055，t = -2.244，p = 0.029), LVMI at follow-up (B = -0.081，t = -3.864，p = 0.000) and tricuspid regurgitation at follow-up (B = -3.797，t = -3.599，p = 0.001).

CONCLUSION

In conclusion, although long-term RVA pacing has significantly effects on left ventricular dyssynchrony, morphology and systolic function in III°AVB patients, the mean LVEF is still >50%. High preimplantation LVMI can predict the decline of LVEF.

Influence of atrioventricular optimization on hemodynamic parameters and quality of life in patients with dual chamber pacemaker with ventricular lead in right ventricular outflow tract

BACKGROUND

The aim of this study was to ascertain whether individual atrioventricular delay (AVD) optimization using impedance cardiography (ICG) offers beneficial hemodynamic effects as well as improved exercise tolerance and quality of life in patients with requiring constant right ventricular pacing.

METHODS

There were 37 patients with advanced AV block included in the study. Several examinations were performed at the beginning. Next, the optimization of AVD by ICG was done. The next step of the study patients have been randomized into optimal AVD group (AVDopt) or factory setting group (AVDfab). After 3 months, the follow-up all data were collected again and crossover was performed. After another 3 months, during the final follow-up all these measures were repeated.

RESULTS

In 87.5% patients, AVDopt were different than factory value. Cardiac output (CO), cardiac index (CI), and stroke volume (SV) were significantly (P < 0.001) higher in AVDopt group than in AVDfab group (CO: 6.0 ± 1.4 L/minute vs. 5.3 ± 1.2 L/minute; SV: 85.8 ± 25.7 mL vs.76.9 ± 22.5 mL; CI: 3.2 ± 0.7 L/minute/m(2) vs. 2.7 ± 0.6 L/minute/m(2) ). There was a statistical significant (P < 0.05) reduction of proBNP and NYHA class in patients with AVDopt compared to AVDfab (proBNP: 196.4 ± 144.7pg/mL vs. 269.4 ± 235.8 pg/mL; NYHA class: 1.7 ± 0.5 vs. 2.3 ± 0.6). Six-minute walking test was significantly (P < 0.05) higher in AVDopt group (409 ± 90 m) than in AVDfab group (362 ± 93 m). There were no statistically significant differences in echocardiographic parameters between AVDopt and AVDfab settings.

CONCLUSION

Our study results suggest that AVD optimization in patients with DDD pacemaker with ICG improves hemodynamic when compared to the default factory settings. Furthermore, optimally programmed AVD reduces BNP and improves exercise tolerance and functional class.

Assessment of ventricular pacing in the setting of an institutional improvement program: insights into physiological pacing

Background

Excessive ventricular pacing is known to be detrimental. The purpose of this study was to assess ventricular pacing in the setting of an institutional improvement program in order to decrease unnecessary pacing.

Method

This cross-sectional single-center study performed in a university hospital assessed 80 consecutive patients attending for a cardiac electronic device (pacemaker or cardioverter defibrillator) check. Forty percent of ventricular pacing was set as the cutoff level beyond which pacing was considered excessive.

Results

Three patients were excluded. Forty-six (59.7%) patients (group 1) had more than 40% ventricular pacing and 31 (40.3%) patients (group 2) showed ventricular pacing less than 41%. In group 1, corrective action was successful in 27 (58.7%) patients, but 19 (41.3%) continued to have ventricular pacing over 40% and were discussed accordingly. An improvement program was established at the institution in order to decrease unnecessary ventricular pacing.

Conclusion

Unnecessary ventricular pacing was encountered in many of the patients in this study, corrective actions were performed, and an institutional improvement project was set up as a consequence.

Perspectives — biological pacing, a clinical reality?

Bradyarrhythmias are common and may be caused by sinus node dysfunction or conduction block. Many of these conditions can be treated by the implantation of electronic cardiac pacemakers that reduce mortality and morbidity in carefully selected patient groups. Implantable electronic pacemakers are small, sophisticated and reliable but not without complication and limitation. Efforts have been made to create a de novo sinus node using gene therapy, the so-called biopacemaker. This approach has potential as permanent cure for bradyarrythmias with greater physiological responsiveness than that provided by rate-responsive electronic pacemakers. This article reviews the current approaches to the problem and gives a perspective on the challenges remaining to bring the therapy to clinical practice.

Selective site pacing: rationale and practical application

Although it has become traditional to place permanent pacemaker leads at the right ventricular apex and right atrial appendage, pacing from these locations poorly mimics normal physiology. A growing evidence base shows that right ventricular apical pacing results in ventricular dyssynchrony and various adverse effects. Provocative data from early trials suggest that pacing from alternate sites in the right ventricle--His bundle pacing, para-Hisian pacing, septal right ventricular outflow tract pacing, and right ventricular midseptal pacing--may lead to improved results. Similarly, early data suggest that right atrial pacing near Bachmann's bundle may lead to superior outcomes when compared with pacing from the right atrial appendage. Several large-scale, randomized clinical trials are now under way to establish the future role of selective site pacing.

Interventional electrophysiology and cardiac resynchronization therapy: delivering electrical therapies for heart failure

Implantable devices have become a readily available option for patients with heart failure. Not only do these patients develop bradycardia and ventricular tachycardia, but their ventricular dysfunction can often improve with cardiac resynchronization therapy. However, this is a complex and rapidly developing clinical science for which the physician chooses techniques and selects patients on the basis of the results of clinical trials, clinical experience, and rapidly evolving tools. The results depend on the interplay of these complex variables. Placement of the left ventricular lead has forced the device physician to develop new skills and/or interdisciplinary relationships with physicians with vascular intervention, imaging, and surgical skills. Familiarity with the cardiac venous anatomy, occlusive venography, venoplasty, guide wire tools, guiding catheters, stenting, and new intracardiac visualization and magnetic intracardiac lead positioning tools are examples of just a few of the novel skills that are useful in the delivery of cardiac resynchronization therapy. Beyond implantation, these patients and devices require specialized follow-up with continued medical therapy and echo-guided adjustments of device programming. Finally, there are ongoing controversies and many as yet unanswered questions that are the subject of ongoing and planned clinical trials.