AV-Block

The objective of this Investigational Device Exemption trial is to confirm the safety and performance of the LivIQ leadless pacemaker system, in patients with a Class I or II indication for ventricular pacing (VVI/VDD) according to applicable guidelines. An integrated atrioventricular synchrony sub-study (AVS) is specifically designed to evaluate the AVS performance of the LivIQ system.

Single-center randomized trial in patients with pacing indication (AV block) after TAVI (transfemoral aortic valve implantation) and LVEF\> 50%, that aims to study the percentage of patients who improve at 12 months in a combined clinical endpoint.

Prospective, non-randomized, multi-center, international study designed to evaluate the initial safety and performance of the ALPS leadless pacemaker when used in patients with bradycardia.

Prospective, non-randomized, multi-center, international study designed to evaluate the initial safety and performance of the ALPS leadless pacemaker when used in patients with bradycardia.

A third generation, Micra AV2 is now available and proposes increased automaticity and improved AV synchrony algorithms based on computing model. The new algorithms permit the delivery of AV synchronous pacing, improving the automatic AV synchrony at faster heart rates between 80-100 bpm with a maximal upper tracking rate limit of 135 bpm (previously 115-120 bpm in the Micra AV1). Micra AV2 presents also a potential extended longevity of 15.6 years (increased by \> 44% in comparison of Micra AV1). Up to now, no clinical study has evaluated the efficacy and safety of Micra AV2 in a real-world setting. The focus of this study is to characterize chronic ambulatory AV synchrony in patients with high degree AV block and normal sinus rhythm implanted with a Micra AV2 as primary objective to evaluate AV synchrony during exercise as secondary objective.

The investigators aim to prospectively test the comparative effectiveness of His or Left bundle branch pacing in relation to patient centered outcomes (quality of life, physical activity, heart failure hospitalization, mortality) and comparative safety in relation to device-related complications and re-interventions (e.g., lead dislodgement, infection) relative to standard of care biventricular pacing in patients with heart failure due to left ventricular systolic dysfunction (LVEF≤50%) and with either a wide QRS (≥130 ms) or with/anticipated \>40% pacing who are already receiving current standard heart failure pharmacological therapy.

Rationale Right ventricular pacing (RVP) is an established and effective therapy for patients with atrioventricular (AV) block. However, frequent RVP has been associated with left ventricular (LV) dyssynchrony and may progess heart failure. Conduction system pacing (CSP), a recently introduced alternative to RVP, aims to preserve physiological ventricular activation by engaging the heart's native conduction system. CSP includes diverse pacing approaches such as selective or non-selective His-bundle pacing, selective left bundle pacing, and LV-septal pacing, each with varying levels of fidelity in reproducing normal conduction. The mechanical impact of these distinct CSP strategies on left and right ventricular (RV) performance remains poorly understood. Cardiac magnetic resonance imaging (CMR), a non-invasive and highly accurate tool for assessing cardiac structure and function, is uniquely positioned to elucidate the effects of CSP and RVP on cardiac performance. This trial aims to evaluate the comparative mechanical effects of these pacing strategies, potentially identifying the optimal approach for improving outcomes in patients with AV block. Objective To investigate and compare the effects of CSP and RVP on cardiac performance, as assessed by CMR and electrocardiographic imaging (ECG-imaging). Main Trial Endpoints The primary endpoints are measures of LV and RV performance assessed via CMR, including: ventricular volumes, ejection fraction (EF), and myocardial strain Secondary Trial Endpoints Secondary endpoints include: Safety and Feasibility: * Adverse events (e.g., troponin release, lead displacement, arrhythmias, heart failure). * Technical feasibility (e.g., ease of device implantation, ability to maintain proper pacing). Electrophysiological Assessment: * Degree of selectivity in engaging the native conduction system. * Ventricular activation times as assessed by ECG-imaging. Trial Design This is a randomized, controlled, single blind, two-center crossover trial. Participants will undergo CSP and RVP in a randomized sequence, each for six months. CMR and ECG-imaging will be performed at 6 months (end of the first pacing phase) and 12 months (end of the second pacing phase). Trial Population The trial will enroll 88 patients with a normal of at most mildly reduced ejection fraction and an indication for ventricular pacing. Interventions Participants will undergo CMR and ECG-imaging at 6 months and 12 months. Ethical Considerations This trial is designed to advance understanding of the mechanical and clinical effects of CSP relative to RVP in patients with AV block. The anticipated benefits include improved cardiac performance and enhanced quality of life. The primary burden to participants is the requirement for an additional CMR scan, which may be perceived as inconvenient or even stressful. The trial minimizes risk by utilizing established clinical procedures and closely monitoring participants for adverse events.

Right ventricular apical pacing (RVAP) can produce left ventricular dysfunction (LVD). Conduction system pacing (CSP) has been used successfully to reverse LVD in patients with left bundle branch block. A recent randomized controlled trial (RCT) has demonstrated that CSP, mostly performed with left bundle branch area pacing (LBBAP), can preserve normal ventricular function and heart failure admissions compared to RVAP in the setting of a high burden of ventricular pacing11 (Stay Trial). Criteria to assess the LBBAP distinguishes those cases in which the LBB is captured (LBBP) from those in which only the muscular septum surrounding the LBB is captured (LVSP). To date, data regarding LVSP to preserve left ventricle ejection fraction (LVEF) is scarce and limited to non-randomized studies.