Atrioventricular Block

Bradyarrhythmias are conditions where the heart beats too slowly, causing symptoms like dizziness, fainting, and fatigue. In some patients, these slow heart rhythms are caused by overactivity of the vagus nerve (the part of the nervous system that slows the heart down). Cardioneuroablation (CNA) is a catheter-based procedure that targets and reduces the effect of these overactive nerves on the heart. It is an alternative to permanent pacemaker implantation, especially for younger patients. Traditionally, CNA is performed using radiofrequency (RF) energy to create small burns in specific areas of the heart. This study investigates whether focal cryoablation (freezing technology using the Freezor™ Xtra catheter) is as safe and effective as standard RF ablation for CNA. This is a prospective, non-randomized study. Participants will receive either RF ablation (N=30) or cryoablation (N=30). The study will evaluate the recurrence of slow heart rhythms and fainting episodes, as well as any complications, over 12 months of follow-up.

The goal of this observational post-market clinical Follow-up study is to learn about the long-term safety, performance, and clinical benefits of pacing the left bundle branch area (LBBAP) using the INGEVITY+ pacemaker lead in patients with bradycardia who need a pacemaker.

This clinical study is a prospective, observational submodule of the BIO\|STREAM.CSP registry designed to evaluate clinical outcomes in patients receiving BIOTRONIK dual-chamber pacemakers that combine conduction system pacing-specifically left bundle branch area pacing (LBBAP)-with Closed Loop Stimulation (CLS). The purpose of the study is to better understand how this combined pacing strategy performs in routine clinical practice and whether it may help reduce the occurrence of atrial fibrillation in patients with sinus node dysfunction (SND) and concomitant atrioventricular (AV) conduction disorders. The primary question the study seeks to answer is what the incidence of device-detected atrial fibrillation (DDAF) is over a 24-month follow-up period in patients treated with LBBAP and active CLS. Additionally, the study explores how CLS dynamically modulates pacing rates when the ventricular lead is positioned within the conduction system, and whether this physiological pacing approach may mitigate the negative effects associated with conventional right ventricular pacing. Overall, this study aims to generate real-world evidence to support optimization of pacemaker programming and to inform clinical decision-making regarding the use of CLS in combination with conduction system pacing, with the goal of improving patient outcomes and reducing atrial arrhythmia burden.

Study objective is to assess whether stimulation of the conduction system reduces cardiac decompensation events in patient follow-up, and how applicable this is in clinical practice and also to determine the impact of the studied interventions in terms of quality of life and cost-effectiveness for the treatment of patients with atrioventricular block. 1260 adult patients who are candidates for pacemaker implantation for the treatment of atrioventricular conduction disease will be randomised to stimulation of the conduction system or to the conventional stimulation.

Transcatheter aortic valve implantation (TAVI) has rapidly expanded over the past decade as a treatment for severe aortic valve stenosis, with over 14,000 procedures performed in France in 2021. A common complication following TAVI is traumatic atrioventricular block requiring pacemaker implantation, occurring in about 10% of patients. Conventional right ventricular pacing in these cases often leads to interventricular dyssynchrony, which can impair left ventricular ejection fraction and increase the risk of hospitalization, heart failure, and mortality. Cardiac resynchronization therapy via biventricular pacing is sometimes proposed as a secondary intervention but involves additional surgery. A newer pacing technique-selective left bundle branch area pacing-has been developed to provide physiological ventricular activation by stimulating conduction pathways distal to the lesion, thereby avoiding dyssynchrony. Retrospective studies suggest clinical benefits, but no prospective randomized trial has yet evaluated its efficacy compared to standard pacing. The objective of this study is to conduct the first randomized clinical trial comparing left bundle branch area pacing versus conventional right ventricular pacing in patients requiring pacemaker implantation due to atrioventricular block after TAVI.

The DRAGON TAVI study is a multicenter, prospective, open, randomised trial, which will enrol 250 patients, randomized 1:1 to the study group (continuous 30-day ECG monitoring with visits triggered by ECG findings) and standard care (ie. control group, which will receive the standard post op 24-48h ECG monitoring and a regular follow-up visit with standard ECG within 30 days). The duration of the study is 12 months ± 1 month.

This prospective, randomized controlled trial aims to evaluate the effect of left bundle branch pacing (LBBP) compared with conventional right ventricular (RV) pacing on the cumulative duration (total time) of atrial high-rate episodes (AHREs) in patients with preserved left ventricular ejection fraction (LVEF) who are expected to require frequent ventricular pacing. Atrial High-Rate Episodes (AHREs) are defined as episodes of atrial tachyarrhythmia that are automatically recorded by device diagnostics and detected by implanted cardiac devices. These episodes usually have an atrial rate ≥170 beats per minute and a duration ≥6 minutes. AHREs are linked to a higher risk of thromboembolic events and clinical atrial fibrillation (AF), and they may indicate subclinical AF or other atrial tachyarrhythmias. Chronic RV pacing has been linked to mechanical and electrical dyssynchrony, which may encourage atrial remodeling and the development of AF. LBBP provides a more physiological ventricular activation and may reduce atrial tachyarrhythmia time (AHRE time). Patients with LVEF \>50% and atrioventricular (AV) conduction disorders requiring a dual-chamber pacemaker will be randomized to either conventional RV septal pacing or LBBP.

Conventional right ventricular pacing (RVP) has been associated with ventricular dyssynchrony and an increased risk of pacing-induced cardiomyopathy, which may lead to worse clinical outcomes. These adverse effects are more pronounced in patients with pre-existing left ventricular dysfunction. To overcome these limitations, left bundle branch area pacing (LBBAP), which directly engages the cardiac conduction system to preserve physiological ventricular activation, has been increasingly adopted in clinical practice. However, in patients with atrioventricular block and preserved left ventricular ejection fraction (LVEF ≥50%), evidence demonstrating the long-term clinical superiority of LBBAP over conventional RVP remains limited. As a result, both pacing strategies continue to be used in current practice. This multicenter randomized trial aims to compare the efficacy, safety, and lead stability of LBBAP using a stylet-driven extendable screw-in lead versus conventional RVP in patients with atrioventricular block and preserved ejection fraction.

A randomized, single-blind study comparing two pacing strategies in patients with atrioventricular block requiring permanent pacemaker implantation. This trial evaluates the impact of conduction system pacing (left bundle branch area pacing) versus standard right ventricular pacing on central hemodynamics, cardiac function, and patient quality of life over 12 months. The study will enroll 124 patients from two Estonian tertiary hospitals and measure central systolic arterial pressure as the primary outcome, with secondary assessments of arterial stiffness, echocardiographic parameters, electrical activation patterns, and quality of life scores.

PROTECT-SYNC study is a multicenter, randomized, controlled trial. A total of 7 medical centers across Republic of Korea will enroll 450 patients during 2 years of enrollment period, and followed for 2 years of follow-up period. The purpose of this study to compare the clinical outcomes of Left Bundle Branch Area Pacing (LBBAP) compared to Right Ventricular Pacing (RVP) in bradyarrhythmia patients who require high burden of ventricular pacing (\>40%).

PACE-AF is a prospective, observational patient registry designed to evaluate the impact of pacemaker algorithms on atrial fibrillation (AF) incidence, progression, and clinical outcomes in patients implanted with dual-chamber pacemakers. The registry aims to include 400-500 patients with longitudinal follow-up. Primary outcomes are progression to permanent AF and all-cause mortality. Secondary outcomes include quality of life, hospitalization, and cardiovascular events.

This is a multicenter, prospective, observational study ,the aim of this study is to find factors affecting selection of double-chamber leadless pacemaker in patients with atrioventricular block and ambulatory atrioventricular synchronous pacing status over time using a leadless ventricular pacemaker.

The goal of this observational study is to evaluate the clinical characteristics of patients undergoing permanent cardiac pacing and to compare procedural efficacy and safety of different implantation approaches in the clinical practice of the participating centres. The contribution of non-fluoroscopic anatomical and electrophysiological reconstruction systems to device implantation procedures will also be evaluated. Participants \[patients over 18 years old with an indication to receive a definitive pacemaker/intracardiac defibrillator implant\] will receive a permanent cardiac pacing implant as requested according to European Society of Cardiology (ESC) guidelines; the investigators will evaluate procedural efficacy and safety of different implantation approaches.

The TELE-SPACER study is a multicenter, noncommercial, physician-initiated, proof-of-concept, prospective, randomized, controlled, unblinded clinical trial and registry designed to compare two methods of treatment of patients with functional Atrio-Ventricular Block (AVB): the guidelines-recommended elective pacemaker (PM) therapy vs cardiovascular autonomic tests (CAT), electrophysiologic assessment (EPS) with referral to cardioneuroablation (CNA) and reevaluation of indications for PM therapy. The main questions TELE-SPACER aims to answer are: * Can the investigators successfully treat functional AVB without implantable device (PM)? * Can the investigators prove the feasibility and safety and demonstrate non-inferiority of CNA procedure in patients with functional AVB, avoiding long-term permanent pacing, its limitations, complications and costs ? The TELE-SPACER trial will validate the European Society of Cardiology (ESC) recommendations (level C of evidence: expert opinion) for elective PM implantation and will introduce CNA as effective treatment in the functional AVB patient population. Functional AVB - defined as a persistent or paroxysmal AVB with a positive results of atropine test

This is a single-center, randomized controlled study. The aim of this study is to compare the impact of left bundle branch area pacing versus traditional right ventricular pacing on the incidence of atrial fibrillation in patients with atrioventricular block.