His-Bundle Pacing in a Patient with Transcatheter Aortic Valve Implantation-Induced Left Bundle Branch Block

Feasibility and Safety of Permanent Left Bundle Branch Pacing in Patients With Conduction Disorders Following Prosthetic Cardiac Valves

Background: The feasibility and safety of left bundle branch pacing (LBBP) in patients with conduction diseases following prosthetic valves (PVs) have not been well described.

Methods: Permanent LBBP was attempted in patients with PVs. Procedural success and intracardiac electrical measurements were recorded at implant. Pacing threshold, complications, and echocardiographic data were assessed at implant and follow-up visit.

Results: Twenty-two consecutive patients with atrioventricular (AV) conduction disturbances (10 with AV nodal block and 12 with infranodal block) underwent LBBP. The PVs included aortic valve replacement (AVR) in six patients, mitral valve repair or replacement (MVR) with tricuspid valve ring (TVR) in four patients, AVR with TVR in one patient, AVR with MVR plus TVR in three patients, transcatheter aortic valve replacement (TAVR) in five patients, and MVR alone in three patients. LBBP succeeded in 20 of 22 (90.9%) patients. LBB potential was observed in 15 of 22 (68.2%) patients, including 10 of 15 (66.7%) patients with AVR/TAVR and five of seven (71.4%) patients without AVR/TAVR. AVR and TVR served as good anatomic landmarks for facilitating the LBBP. The final sites of LBBP were 17.9 ± 1.4 mm inferior to the AVR and 23.0 ± 3.2 mm distal and septal to the TVR. The paced QRS duration was 124.5 ± 13.8 ms, while the baseline QRS duration was 120.0 ± 32.5 ms (P = 0.346). Pacing threshold and R-wave amplitude at implant were 0.60 ± 0.16 V at 0.5 ms and 11.9 ± 5.5 mV and remained stable at the mean follow-up of 16.1 ± 10.8 months. No significant exacerbation of tricuspid valve regurgitation was observed compared to baseline.

Conclusion: Permanent LBBP could be feasibly and safely obtained in the majority of patients with PVs. The location of the PV might serve as a landmark for guiding the final site of the LBBP. Stable pacing parameters were observed during the follow-up.

Impact of Preprocedural Aortic Valve Calcification on Conduction Disturbances after Transfemoral Aortic Valve Replacement

AIM

The present study analyzes in depth the impact of different calcification patterns on disturbances of the conduction system in transcatheter aortic valve replacement (TAVR) patients.

METHODS AND RESULTS

A total of 169 preprocedural TAVR multislice computed tomography scans from consecutive transfemoral (TF) TAVRs performed between 2014 and 2017 using either Edwards SAPIEN or Medtronic Evolut R valves were retrospectively evaluated. The volume, distribution, and orientation of annular and valvular aortic valve calcification were measured and their impact on postoperative conduction disturbances was determined using linear and logistic regression analyses. The total volume of calcification and distribution at the aortic annulus or valve did not influence the conduction system. Oval calcification of the left aortic cusp was independently associated with an elevated risk for an increase in atrioventricular block degree (+0.6, p = 0.03). Moreover, orthogonal calcifications at the level of the aortic annulus were associated with an increased risk for QRS prolongation (+26 ms, p = 0.004) and an increased risk for permanent pacemaker implantation (OR 4.3, p = 0.03) after TF TAVR. This was more pronounced in patients undergoing TF TAVR using a balloon-expandable Edwards SAPIEN 3 valve (QRS +38.195 ms, p < 0.001; OR permanent pacemaker 15.48, p = 0.013).

CONCLUSION

Orthogonal annular calcification confers an increased risk for conduction disturbances after TAVR. This is even more pronounced after implantation of balloon-expandable valves.

Feasibility and stability of left bundle branch pacing in patients after prosthetic valve implantation

BACKGROUND

Left bundle branch pacing (LBBP) has emerged as a promising pacing modality for preventing pacing induced cardiomyopathy in patients complicated with conduction abnormalities (CAs) after prosthetic valve (PV) implantation.

OBJECTIVE

The present study aimed to evaluate the safety and feasibility of LBBP in this patient population.

METHODS

LBBP was attempted in 20 patients complicated with atrioventricular block after PV implantation. Surface, intracardiac electrical measurements, and echocardiographic data were documented. Lead parameters and complications were routinely tracked at implantation and each follow-up visit.

RESULTS

LBBP was successful in 90% (18/20) participants. The paced QRS duration and the stimulus to left ventricular activation time were 106.8 ± 6.8 ms and 65.5 ± 5.4 ms, respectively. Left bundle branch (LBB) potential was recorded in 61.1% (11/18) patients who succeeded in LBBP. During the procedure, the mean unipolar myocardium capture threshold was 0.51 ± 0.15 V@0.4 ms while the unipolar bundle capture threshold was 0.84 ± 0.51 V@0.4 ms. The mean fluoroscopic exposure time and the radiation dose were 13.0 ± 9.2 min and 81.7 ± 8.3 mGy, respectively. The average follow-up period was 10.4 ± 5.9 months (range 3-23 months). Pacing parameters remained stable and no significant lead-related complications occurred during the whole observation period.

CONCLUSIONS

LBBP was safe and feasible in patients with PVs. Acceptable and stable pacing parameters could be expected during the procedure and the follow-ups.