Recovery of complete left bundle branch block following heart failure improvement by left bundle branch pacing in a patient

Comparison of the safety and efficiency of temporary cardiac pacing methods during left bundle branch pacemaker implantation: Femoral vein pacing versus atrial spiral pacing with electrodes placed at the ventricle

BACKGROUND

Left bundle branch pacemakers (LBBPs) can better maintain ventricular electrical synchronization than traditional right ventricular pacing (RVP). Temporary cardiac pacing (TCP) is needed to ensure the safety of the operation in patients undergoing LBBP. Currently, there are two methods of installing TCP in conventional permanent pacemaker implantation.

HYPOTHESIS

To evaluate the safety and efficiency of replacing femoral vein pacing with atrial spiral pacing in the right ventricle for temporary cardiac pacing (TCP) during left bundle branch pacemaker (LBBP) implantation.

METHOD

A total of 179 patients who underwent TCP during LBBP were selected for retrospective analysis from April 2019 to 2021 and divided into two groups: the atrial spiral electrode group (n = 76) and the femoral vein electrode group (n = 103). The following were observed: operation time; radiation dose; radiation time; operation expenses; hospitalization time; pacemaker parameters immediately after the operation and at 1 week, 1 month, 3 months, and 6 months after the operation; operation complications and femoral vein puncture point complications were observed in the two groups.

RESULTS

Compared to the femoral vein electrode group, the atrial electrode group had significantly lower operation times ([116.86 ± 24.63] versus [128.94 ± 25.27] min, p < 0.05), radiation doses ([805.07 ± 132.94] versus [846.42 ± 87.37] mgy, p < 0.05), and decreased risk of a displaced or dislodged temporary pacing electrode during the operation ([0.00%] versus [4.85%], p < 0.05). The atrial electrode group did not have significant operation costs or material costs associated with femoral vein temporary pacing electrode implantation. In addition, the atrial electrode group did not have an increased risk of pacemaker-related infections, and the parameters of the pacemaker were unaffected. However, some puncture point complications appeared in the femoral vein electrode group (8 cases of local subcutaneous hematoma, 3 cases of pseudoaneurysms, 3 cases of arteriovenous fistula).

CONCLUSION

The replacement of the femoral vein pacing electrode with an atrial spiral pacing electrode in the right ventricle for TCP during LBBP implantation was safe and effective.

Anatomical and histological assessment of left bundle branch area pacing in human heart with refractory heart failure

As an emerging pacing technique, left bundle branch area pacing (LBBAP) has served as a physiological pacing modality that overcomes the limitations of His bundle pacing (HBP) or right ventricular pacing. Three patients with terminal heart failure who were waiting for heart transplantation and met the indications of pacemaker implantations received LBBAP. Symptoms were relieved and stabilized and eventually received heart transplantation. Diseased hearts from the recipients were dissected post‐transplantation, and the direct visual of pacing lead locations in the interventricular septum were evaluated, and the histopathological examination around the lead was conducted for the first time in human. As a result, we found that the locations of LBBAP leads were matched with fluoroscopic views during the procedure and Masson's staining showed extensive fibrosis occur around the lead but did not result in high thresholds.

Left Bundle Branch Pacing: Current Knowledge and Future Prospects

Cardiac pacing is an effective therapy for treating patients with bradycardia due to sinus node dysfunction or atrioventricular block. However, traditional right ventricular apical pacing (RVAP) causes electric and mechanical dyssynchrony, which is associated with increased risk for atrial arrhythmias and heart failure. Therefore, there is a need to develop a physiological pacing approach that activates the normal cardiac conduction and provides synchronized contraction of ventricles. Although His bundle pacing (HBP) has been widely used as a physiological pacing modality, it is limited by challenging implantation technique, unsatisfactory success rate in patients with wide QRS wave, high pacing capture threshold, and early battery depletion. Recently, the left bundle branch pacing (LBBP), defined as the capture of left bundle branch (LBB) via transventricular septal approach, has emerged as a newly physiological pacing modality. Results from early clinical studies have demonstrated LBBP's feasibility and safety, with rare complications and high success rate. Overall, this approach has been found to provide physiological pacing that guarantees electrical synchrony of the left ventricle with low pacing threshold. This was previously specifically characterized by narrow paced QRS duration, large R waves, fast synchronized left ventricular activation, and correction of left bundle branch block. Therefore, LBBP may be a potential alternative pacing modality for both RVAP and cardiac resynchronization therapy with HBP or biventricular pacing (BVP). However, the technique's widespread adaptation needs further validation to ascertain its safety and efficacy in randomized clinical trials. In this review, we discuss the current knowledge of LBBP.

Feasibility and efficacy of left bundle branch area pacing in patients indicated for cardiac resynchronization therapy

AIMS

The present study was to evaluate the feasibility and clinical outcomes of left bundle branch area pacing (LBBAP) in cardiac resynchronization therapy (CRT)-indicated patients.

METHODS AND RESULTS

LBBAP was performed via transventricular septal approach in 25 patients as a rescue strategy in 5 patients with failed left ventricular (LV) lead placement and as a primary strategy in the remaining 20 patients. Pacing parameters, procedural characteristics, electrocardiographic, and echocardiographic data were assessed at implantation and follow-up. Of 25 enrolled CRT-indicated patients, 14 had left bundle branch block (LBBB, 56.0%), 3 right bundle branch block (RBBB, 12.0%), 4 intraventricular conduction delay (IVCD, 16.0%), and 4 ventricular pacing dependence (16.0%). The QRS duration (QRSd) was significantly shortened by LBBAP (intrinsic 163.6 ± 29.4 ms vs. LBBAP 123.0 ± 10.8 ms, P < 0.001). During the mean follow-up of 9.1 months, New York Heart Association functional class was improved to 1.4 ± 0.6 from baseline 2.6 ± 0.6 (P < 0.001), left ventricular ejection fraction (LVEF) increased to 46.9 ± 10.2% from baseline 35.2 ± 7.0% (P < 0.001), and LV end-diastolic dimensions (LVEDD) decreased to 56.8 ± 9.7 mm from baseline 64.1 ± 9.9 mm (P < 0.001). There was a significant improvement (34.1 ± 7.4% vs. 50.0 ± 12.2%, P < 0.001) in LVEF in patients with LBBB.

CONCLUSION

The present study demonstrates the clinical feasibility of LBBAP in CRT-indicated patients. Left bundle branch area pacing generated narrow QRSd and led to reversal remodelling of LV with improvement in cardiac function. LBBAP may be an alternative to CRT in patients with failure of LV lead placement and a first-line option in selected patients such as those with LBBB and heart failure.