Pacemaker-Induced Cardiomyopathy

Conventional pacemakers involve placing a lead through a valve into the bottom right chamber of the heart. Research has shown that this approach is associated with an increased risk of valve dysfunction, mortality, and impairment of cardiac function. Newer pacemakers, such as leadless pacemakers and pacemakers that engage directly with the heart's native conduction system (known as left bundle branch pacemakers), are increasingly being adopted. However, the impact of these newer pacing technologies on cardiac function and the tricuspid valve, as well as how they compare with each other, remains unclear. The investigators aim to study the impact of leadless pacemakers and left bundle branch pacemakers on cardiac function and the tricuspid valve by conducting an acute study in addition to the routine pacemaker implantation procedure for which participants have been referred. Both procedures will be performed during a single session under general anaesthesia. Outcomes from this study will improve understanding of how these pacing technologies affect cardiac and valvular function and how they compare with each other. These findings will help guide decision-making regarding the optimal type of pacemaker to adopt, particularly for patients at greatest risk of developing tricuspid valve dysfunction or impaired cardiac function.

Development of pacing induced cardiomyopathy (PICM) is correlated to a high morbidity as signified by an increase in heart failure admissions and mortality. At present a lack of data leads to a failure to identify patients who are at risk of PICM and would benefit from pre-selection to physiological pacing. In the light of the foregoing, there is an urgent need for novel non-invasive detection techniques which would aid risk stratification, offer a better understanding of the prevalence and incidence of PICM in individuals with pacing devices and the contribution of additional risk factors.

LEAP-CAR will evaluate the benefit of left bundle branch area pacing (LBBAP), comparing to conventional right ventricular pacing (RVP), in preventing pacing-induced cardiomyopathy (PICM) in patients undergoing pacemaker implant for advanced (2° or 3° degree) atrioventricular block, with baseline left ventricular ejection fraction (LVEF) \>45%. LEAP-CAR is a randomized, prospective, double blind clinical trial.

This randomized study compares the effects of conventional (right ventricular pacing in patients with LVEF ≥ 40% and cardiac resynchronization therapy in patients with LVEF \< 40 %) versus left bundle branch pacing on left ventricular remodelling in patients with reduced left ventricular ejection fraction (\< 50 %) that need permanent pacemaker implantation after transcatheter aortic valve implantation (TAVI).