Feasibility and safety of left bundle branch area pacing in cardiac amyloidosis. A single center experience

BACKGROUND

Conventional right ventricle (RV) pacemaker stimulation has been associated with worse clinical outcomes in patients with cardiac amyloidosis (CA). Left bundle branch area pacing (LABPP) has been suggested as a promising alternative. We sought to assess the safety, feasibility, and outcomes of LABPP in patients with CA.

METHODS

We retrospectively analyzed echocardiography and pacing parameters and clinical outcomes in 23 consecutive patients with CA and LBBAP implanted from June 2020 to October 2022.

RESULTS

LBBAP was successfully performed in 22 over 23 patients (19 male, 78.6 ± 11.7 years, 20 ATTR, mean LVEF 45.5 ± 16.2%). After the procedure, 9 patients showed Qr pattern and 11 a qR pattern in V1 on ECG. Average procedure time was 67 ± 28 min. After 7.7 ± 5.2 months follow-up, no procedure-related complications had occurred. Although, a significant reduction in QRS width (p = .001) was achieved, we did not observe significant changes in LVEF and Nt ProBNP at 6 months of follow-up. Pacing parameters were stable during follow-up: LBB capture threshold and R wave amplitude were 1.0 ±  0.5 V and 10.6 ± 6.0 mV versus 0.8 ±  0.1 V, p = .21 and 10.6 ± 5.1 mV (p = .985) at follow up.

CONCLUSION

LBBAP is safe and feasible pacing technique for patients with CA. LBBAP is associated with significant narrowing of QRSd without worsening in LVEF and Nt-proBNP.

A case report-facing blues in cardiac amyloidosis: no more a zebra

Background

Cardiac amyloidosis presentation in an affected individual can be varied. We describe a patient who had the entire spectrum of involvement in his life time. Initially presented as an ischaemic heart disease and later developed complete heart block (CHB) and frank cardiomyopathy. Increased load of amyloid caused lead-tissue interface disruption resulting in high pacing thresholds with difficulty in capture during permanent pacemaker implantation requiring a novel strategy of management.

Case summary

A 65-year-old male presented with two episodes of syncope with a history of gradually progressive dyspnoea of 6 months duration along with lower limb swelling for last 1–2 months. He had a history of drug-eluting stent implantation for stable ischaemic heart disease 4 years back. Now he presented with a CHB and a transthoracic echocardiogram hinted towards a restrictive physiology and an infiltrative disease. Cardiac magnetic resonance imaging could not be done in view of the incompatible temporary pacemaker on which the patient was dependent. Abdominal fat pad biopsy was positive for amyloid. He was taken up for permanent pacemaker implantation; however, multiple attempts could not achieve desired threshold and capture amplitudes in the right ventricular apex, septum, or outflow region. The lead was placed in the coronary sinus and a stent was placed proximally to trap the lead behind the deployed stent. Threshold and impedance were satisfactory. Cardiac biopsy subsequently confirmed aTTR amyloidosis.

Discussion

The patient had an ischaemic heart disease, conduction disease, and cardiomyopathy as the manifestation of cardiac amyloidosis. While two-dimensional echo is the screening tool of choice, cardiac biopsy remains the gold standard of diagnosis for amyloidosis. Cardiac pacing comes with its own unique set of challenges in patients with advanced amyloid cardiomyopathy and have to be overcome for symptomatic benefit of the patient. Coronary sinus may be utilized in such patients for single-site ventricular pacing and placing a stent may help to anchor the lead when placed within it.