Navigating Challenging Left Ventricular Lead Placements for Cardiac Resynchronization Therapy

His-Purkinje system pacing versus biventricular pacing in clinical efficacy: a systematic review and meta-analysis

BACKGROUND

His-Purkinje system pacing (HPSP), including his-bundle pacing (HBP) and left bundle branch area pacing (LBBaP), imitates the natural conduction of the heart as an alternative to biventricular pacing (BVP) in cardiac resynchronization therapy (CRT). However, the feasibility and efficacy of HPSP were currently only evidenced by studies with a limited sample size, so this study aimed to provide a comprehensive assessment through a systematic review and meta-analysis.

METHODS

In order to compare the clinical outcomes associated with HPSP and BVP in patients for CRT, PubMed, EMBASE, Cochrane Library and Web of Science database were searched from inception to April 10, 2023. Clinical outcomes of interest including QRS duration (QRSd), left ventricular (LV) function and New York Heart Association (NYHA) functional classification, pacing threshold, echocardiographic and clinical response, hospitalization rate of HF and all-cause mortality were also extracted and summarized for meta-analysis.

RESULTS

A total of 13 studies (ten observational studies and three randomized studies) involving 1,121 patients were finally included. The patients were followed up for 6-27 months. Compared with BVP, CRT patients treated by HPSP presented shorter QRSd [mean difference (MD): -26.23 ms, 95% confidence interval (CI): -34.54 to -17.92, P < 0.001, I² = 91%], greater LV functional improvement with increased left ventricular ejection fraction (LVEF) (MD: 6.01, 95% CI: 4.81 to 7.22, P < 0.001, I² = 0%), decreased left ventricular end-diastolic dimension (LVEDD) (MD: -2.91, 95% CI: -4.86 to -0.95, P = 0.004, I² = 35%), and more improved NYHA functional classification (MD: -0.45, 95% CI: -0.67 to -0.23, P < 0.001, I² = 70%). In addition, HPSP was more likely to have higher echocardiographic [odds ratio (OR): 2.76, 95% CI: 1.74 to 4.39, P < 0.001, I² = 0%], clinical (OR: 2.10, 95% CI: 1.16 to 3.80, P = 0.01, I² = 0%) and super clinical (OR: 3.17, 95% CI: 2.09 to 4.79, P < 0.001, I² = 0%) responses than BVP, and a lower hospitalization rate of HF (OR: 0.34, 95% CI: 0.22 to 0.51, P < 0.001, I² = 0%), while presented no difference (OR: 0.68, 95% CI: 0.44 to 1.06, P = 0.09, I² = 0%) in all-cause mortality compared with BVP. With threshold change taking into account, BVP was less stable than LBBaP (MD: -0.12 V, 95% CI: -0.22 to -0.03, P = 0.01, I² = 57%), but had no difference with HBP (MD: 0.11 V, 95% CI: -0.09 to 0.31, P = 0.28, I² = 0%).

CONCLUSION

The present findings suggested that HPSP was associated with greater improvement of cardiac function in patients with indication for CRT and was a potential alternative to BVP to achieve physiological pacing through native his-purkinje system.

Approaches for Successful Implantation of Cardiac Implantable Devices in Patients with Persistent Left Superior Vena Cava

Persistent left superior vena cava (PLSVC) is the most common congenital thoracic venous anomaly, with 0.47% of patients undergoing pacemaker or cardiac implantable device placement found to have PLSVC. This review article describes challenges and interventions to successfully insert cardiac implantable electronic device leads into patients with PLSVC by providing multiple unique case examples.

Success rates, challenges and troubleshooting of left bundle branch area pacing as a cardiac resynchronization therapy for treating patients with heart failure

Cardiac resynchronization therapy (CRT) is an important treatment of heart failure patients with reduced left ventricular ejection fraction (LVEF) and asynchrony of cardiac electromechanical activity. Left bundle branch area pacing (LBBaP) is a novel physiological pacing modality that appears to be an effective method for CRT. LBBaP has several advantages over the traditional biventricular-CRT (BiV-CRT), including a low and stable pacing capture threshold, a high success rate of implantation, a short learning curve, and high economic feasibility. However, LBBaP is not suitable for all heart failure patients needing a CRT and the success rates of LBBaP in heart failure patients is lower because of myocardial fibrosis, non-specific intraventricular conduction disturbance (IVCD), enlargement of the right atrium or right ventricle, etc. In this literature review, we summarize the success rates, challenges, and troubleshooting of LBBaP in heart failure patients needing a CRT.

The usefulness of proximal anchor balloon technique during implantation of a cardiac resynchronization therapy device in a patient with complex coronary venous anatomy: a case report

Background

Cardiac resynchronization therapy (CRT) is an accepted device treatment in stable heart failure (HF) patients. In recent years increased awareness of coronary anatomy and implantation techniques have significantly impacted this evolving therapy.

Case presentation

In this article, we present a case describing the usefulness of the proximal balloon anchoring technique to enable initial coronary sinus (CS) cannulization and left ventricular (LV) lead placement in the tortuous coronary sinus during CRT implantation.

Conclusions

The proximal anchor balloon technique can easily enable coronary sinus cannulization and left ventricular lead placement in patients with complex venous anatomy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-022-02484-1.

A successful placement of the left ventricular lead for the cardiac resynchronization device using the orthodromic snare technique: clinical case

Background: The main aim of Cardiac Resynchronization Therapy (CRT) is a positive response of the patient, particularly, reduction of the symptoms and improvement of the heart contractility, that can be reached in 5070% of patients. The possibility of appropriate positioning the left ventricular (LV) lead is of great importance for the response to CRT. Certain instruments and technical approaches are used for the placement of the LV lead. Here, we describe the use of the orthodromic snare technique, which is quite rare in practice, but allows one to overcome some anatomical obstacles. Clinical case description: Patient A., suffering from the heart failure with a low ejection fraction and left bundle branch block, was admitted to the hospital for CRT implantation. Before the operation, all the necessary routine instrumental and laboratory diagnostics was performed. During the operation, venography of the cardiac veins revealed unsuitability of the lateral cardiac vein for the placement of the LV lead due to its very small diameter. The posterolateral vein was suitable for the LV lead implantation but still had some anatomical difficulties: an acute angle of inflow and local stenosis in the proximal segment. During the procedure, the following techniques were used without success: positioning the LV lead by a simple translational movement forward, a subselective catheter, introduction of several coronary guides in order to smooth out the acute angle of inflow. These circumstances warranted the use of the orthodromic snare technique for a successful LV lead placement. Conclusion: This clinical case illustrates the possibility of a safe and effective use of the orthodromic snare technique for LV lead implantation. Such anatomical difficulties as a small diameter, acute angle of inflow, local stenosis have also been illustrated and discussed.

Optimal CRT Implantation-Where and How To Place the Left-Ventricular Lead?

Purpose of Review

Cardiac resynchronization therapy (CRT) represents a well-established and effective non-pharmaceutical heart failure (HF) treatment in selected patients. Still, a significant number of patients remain CRT non-responders. An optimal placement of the left ventricular (LV) lead appears crucial for the intended hemodynamic and hence clinical improvement. A well-localized target area and tools that help to achieve successful lead implantation seem to be of utmost importance to reach an optimal CRT effect.

Recent Findings

Recent studies suggest previous multimodal imaging (CT/cMRI/ECG torso) to guide intraprocedural LV lead placement. Relevant benefit compared to empirical lead optimization is still a matter of debate. Technical improvements in leads and algorithms (e.g., multipoint pacing (MPP), adaptive algorithms) promise higher procedural success. Recently emerging alternatives for ventricular synchronization such as conduction system pacing (CSP), LV endocardial pacing, or leadless pacing challenge classical biventricular pacing.

Summary

This article reviews current strategies for a successful planning, implementation, and validation of the optimal CRT implantation. Pre-implant imaging modalities offer promising assistance for complex cases; empirical lead positioning and intraoperative testing remain the cornerstone in most cases and ensure a successful CRT effect.

Left Bundle Branch Area Pacing vs. Biventricular Pacing for Cardiac Resynchronization Therapy: A Meta-Analysis

Background: Left bundle branch area pacing (LBBAP) is a recently proposed method for conduction system pacing. We performed a meta-analysis of controlled studies to compare the clinical outcome in patients who received LBBAP vs. biventricular pacing (BVP) for cardiac resynchronization therapy (CRT).

Methods: PubMed, Embase, and Cochrane's Library databases were searched for relevant controlled studies. A random-effect model incorporating the potential heterogeneity was used to synthesize the results.

Results: Four non-randomized controlled studies including 249 patients with heart failure (HF) for CRT were included, and the patients were followed for 6–12 months. Compared with BVP, LBBAP was associated with significantly shortened QRS duration [mean difference (MD): −29.18 ms, 95% confidence interval (CI): −33.55–24.80, I² = 0%, P < 0.001], improved left ventricular ejection fraction (MD: 6.93%, 95% CI: 4.69–9.17, I² = 0%, P < 0.001), reduced left ventricular end-diastolic dimension (MD: −2.96 mm, 95% CI: −5.48 to −0.44, I² = 0%, P = 0.02), and improved New York Heart Association class (MD: −0.54, 95% CI: −0.84 to −0.24, I² = 65%, P < 0.001). Moreover, patients who received LBBAP were more likely to achieve echocardiographic [odds ratio (OR): 5.04, 95% CI: 2.17–11.69, I² = 0%, P < 0.001] and clinical (OR: 7.33, 95% CI: 1.62–33.16, I² = 0%, P = 0.01) CRT responses.

Conclusion: Current evidence from non-randomized studies suggests that LBBAP appears to be a promising method for CRT, which is associated with more remarkable improvements of symptoms and cardiac function in HF patients with indication for CRT.