An interventional study of Right Ventricular Pacing and Left Bundle Branch Pacing in Atrial Fibrillation (AF), Pacemaker Therapy and Atrioventricular Block, sponsored by University Hospital of Patras. Recruiting at 1 site in Greece. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-03-13.
Sponsored by University Hospital of Patras · Not applicable, Interventional, and Prevention
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.
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.
Device Algorithm Specificity: AHREs will be validated by reviewing the stored atrial electrograms (EGMs) for a random sample of at least 20% of detected episodes to confirm atrial origin, exclude oversensing, and differentiate atrial tachycardia from atrial fibrillation-like episodes. Device model-specific detection thresholds, including refractory oversensing behavior, atrial blanking periods, and sensitivity parameters, will be documented and standardized across participants where possible.
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).
LBBP produces a narrower paced QRS, shorter left ventricular activation time, and more synchronous ventricular contraction compared with RV pacing. These electrophysiologic differences may reduce atrial stretch, left atrial pressure, and atrial substrate remodeling, which are mechanisms believed to lower AHRE burden.
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.
4,009 studies on the registry are indexed under Atrial Fibrillation; 961 are open to participants now.
This study's planned enrollment of 244 is above the median of 150 across 2,476 interventional studies indexed under Atrial Fibrillation.
Browse Atrial Fibrillation studies →University Hospital of Patras is the lead sponsor of 43 studies on the registry; 11 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Permanent complete heart block Permanent second-degree AV block (Mobitz II or Mobitz I)
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
LVEF (left ventricular ejection fraction)
The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Life expectancy
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Procedure: Standard right ventricular septal pacing Description: Implantation of a dual-chamber pacemaker with the ventricular lead placed in the RV septum. At follow-up, the ventricular pacing percentage and pacing configuration will be noted.
Device: Right Ventricular Pacing
Procedure: Left bundle branch pacing lead implantation Description: Implantation of a dual-chamber pacemaker with the ventricular lead placed at the left bundle branch area. Physiological pacing will be programmed into the devices and, at follow-up, the percentage of spontaneous pacing will be noted.
Device: Left Bundle Branch Pacing
Implantation of a dual-chamber pacemaker with the ventricular lead placed in the RV septum. At follow-up, the ventricular pacing percentage and pacing configuration will be noted. All devices used in this study are commercially available in the European Union and carry a valid CE mark.
Implantation of a dual-chamber pacemaker with the ventricular lead placed at the left bundle branch area. Physiological pacing will be programmed into the devices and, at follow-up, the percentage of spontaneous pacing will be noted. All devices used in this study are commercially available in the European Union and carry a valid CE mark.
Total cumulative AHRE time for device-detected episodes lasting >6 minutes
Sum of the durations of all device-detected AHREs with individual episode duration \>6 minutes (atrial rate threshold per device diagnostics, typically ≥170 bpm), expressed as total time (minutes/hours). Total analyzable monitoring time will be defined as the interval from implantation to the last successful device interrogation/remote transmission, excluding periods of missing device data.
Time frame: From pacemaker implantation (or randomization) to 24 months (primary endpoint)
Total cumulative time in AHRE episodes with individual episode duration 0 to 6 minutes.
Time frame: From pacemaker implantation (or randomization) to 24 months (primary endpoint)
Total cumulative time in AHRE episodes with individual episode duration 6 minutes to 6 hours.
Time frame: From pacemaker implantation (or randomization) to 24 months
Total cumulative time in AHRE episodes with individual episode duration 6 hours to 24 hours.
Time frame: From pacemaker implantation (or randomization) to 24 months
Total cumulative time in AHRE episodes with individual episode duration >24 hours.
Time frame: From pacemaker implantation (or randomization) to 24 months
Time to event - for AHRE episodes > 6 min
Time frame: From pacemaker implantation (or randomization) to 24 months
Incidence of progression to clinically documented atrial fibrillation (paroxysmal or persistent, symptomatic or asymptomatic, confirmed by ECG, Holter, or wearable monitoring).
Time frame: From pacemaker implantation (or randomization) to 24 months
Time to first clinically documented atrial fibrillation.
Time frame: From pacemaker implantation (or randomization) to 24 months
Development of permanent atrial fibrillation.
Atrial fibrillation (AF) will be evaluated using routine interrogation of implanted pacemakers, which provide device-recorded atrial arrhythmia data, including AF burden and episode duration. Permanent atrial fibrillation will be defined according to the ESC Guidelines for Atrial Fibrillation and will require a consensus decision between the treating physician and the patient that the arrhythmia is ongoing. This consensus will also include an agreement to pursue a rate-control strategy with no further attempts to restore or maintain sinus rhythm.
Time frame: From pacemaker implantation (or randomization) to 24 months
Time to progression to permanent atrial fibrillation.
Time frame: From pacemaker implantation (or randomization) to 24 months
Device- or procedure-related complications (e.g., cardiac perforation, pericardial tamponade, pneumothorax, hemothorax, infection requiring antibiotics or system removal, generator or lead malfunction, hematoma).
Time frame: From pacemaker implantation (or randomization) to 24 months
All-cause mortality.
Time frame: From pacemaker implantation (or randomization) to 24 months
Hospitalization due to AF
Time frame: From pacemaker implantation (or randomization) to 24 months
Hospitalization due to HF
Time frame: From pacemaker implantation (or randomization) to 24 months
Need for cardioversion.
Time frame: From pacemaker implantation (or randomization) to 24 months
Development of pacing-induced cardiomyopathy (PICM)
Defined as a drop in LVEF of at least 10 percentage points resulting in LVEF \<50%, or a relative reduction in global longitudinal strain of at least 15%
Time frame: From pacemaker implantation (or randomization) to 24 months
Changes in biomarkers associated with myocardial stress, inflammation, or injury
NT-proBNP, hsCRP, and troponin
Time frame: At baseline and at 12 and 24 months, where available.
Changes in structured echocardiographic parameters
Including left atrial strain, left atrial volume index, interventricular mechanical delay, left ventricular mechanical delay, and global longitudinal strain, in participants with available echocardiographic studies from centers able to perform these measurements.
Time frame: At baseline and at 12 and 24 months, where available.
Quality-of-life change assessed using a validated questionnaire during follow-up.
Minnesota living with heart-failure questionnaire
Time frame: At baseline and at 3,6,12,18 and 24 months
Plan to share: Undecided
Started Feb 2026 (actual). Primary completion is estimated for Apr 2029, 38 months after the start.
Of 796 non-industry interventional studies with no phase under Atrial Fibrillation, half reached primary completion within 40 months of starting (the median), counting those still running; a quarter within 21 and three quarters within 59. This study's planned 38 months is close to that.
Counting every sponsor, half of 1,051 studies reached it within 33 months; a quarter within 18 and three quarters within 54.
How these figures are worked out, and which studies are left out of them.
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University Hospital of Patras