NCT06601322

Functional Outcomes in CondUction System Pacing and Right Ventricular Synchrony (FOCUS-Right)

Functional Outcomes in CondUction System Pacing and Right Ventricular Synchrony The FOCUS-Right Pilot Study (FOCUS-Right)

• Status: Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 20 (estimated)
• Sponsor: Virginia Commonwealth University · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

The goal of this prospective single center clinical trial is to evaluate the safety and feasibility of performing simultaneous exercise stress cardiac magnetic resonance (CPET-CMR) and cardiopulmonary exercise testing in patients with pre-existing left bundle branch area pacemakers (LBBAP) programmed to an atrial sensing mode. Measurements of right ventricular, left ventricular function, and exercise capacity will be obtained at various LBBAP programming parameters at rest and during low intensity exercise. The main aims of the study are: * Demonstrate the safety and feasibility of performing CPET-CMR in patients with pre-existing LBBAP programmed to P-synchronous ventricular pacing mode. * Generate preliminary data evaluating differences in RV function, LV function, and exercise capacity during various pacemaker programming settings.

Detailed description

Conduction system pacing, namely left bundle branch area pacing (LBBAP) represents an important pacing modality introduced to avoid the deleterious effects of non-physiologic ventricular activation during chronic right ventricular pacing and /or left bundle branch block (LBBBP). Previous studies have demonstrated that LBBAP exhibits similar or superior left ventricular resynchronization compared to conventional treatment modalities, the impact of this novel pacing strategy on the right ventricle has not yet been addressed. This study aims to demonstrate the safety and feasibility of assessing LBBAP performance with a focus on right ventricular function in a novel way utilizing Cardiopulmonary Exercise Testing and Exercise Stress Cardiac Magnetic Resonance. The investigators plan a 1-day prospective non-randomized controlled pilot study in which up to 20 subjects with left bundle branch area pacemakers with evidence of output dependent anodal capture will undergo low intensity exercise CPET-CMR at three different LBBAP settings (underlying rhythm, non-selective left bundle pacing, non-selective left bundle pacing with anodal stimulation).

Conditions

• Left Branch Bundle Block
• RV - Right Ventricular Abnormality

Interventions

Type	Name	Description
OTHER	Pacemaker Interrogation and Electrocardiogram (ECG):	Prior to the CMR study, subjects will undergo baseline interrogation of their dual chamber LBBAP to assess for appropriate device function. Lead capture characteristics will then be assessed with continuous intracardiac electrogram characteristics recorded from the atrial and ventricular lead with simultaneous 12-lead ECG rhythm strip recordings to assess for settings at which the investigators can differentiate aLBBAP, sLBBAP and nsLBBAP. Pacing output will be increased until left bundle branch area pacing with anodal capture is achieved, and then decreased until anodal capture is lost. These programming parameters will be recorded and utilized for Phase 2-3 of the CPET-CMR scan. 12-lead ECG rhythm strips of QRS morphology with each parameter set will be obtained and saved for later analysis.
OTHER	Cardiopulmonary Exercise Test (CPET) and Exercise Stress Cardiac Magnetic Resonance (ExeCMR	Following ECG and pacemaker analysis as above for safety, subjects will be fitted with 2 sets of MRI-compatible ECG monitoring systems a BP monitoring system , and a finger-tip pulse gating system. Imaging will be performed on a Magnetom Vida 3 Tesla scanner by trained CRM radiology technologists.
OTHER	Continuous pacemaker telemetry (CPT)	CPT will be established and supervised by a cardiac electrophysiologist to monitor for evidence of noise or artifact which may lead to inability to appropriately sense native atrial depolarization in DDD mode. Subjects with PM dependence are excluded. If noise is noted during scanning with NVP, then scanning will NOT be performed during P-synchronous pacing and will instead be performed during overdrive pacing at a rate above the patients maximal achieved heart rate with exertion during Phase 1. Thus, there is minimal risk to the subject from PM programming during CPET-CMR.

Timeline

• Start date: 2024-08-23
• Primary completion: 2026-05-01
• Completion: 2026-05-01
• First posted: 2024-09-19
• Last updated: 2026-04-16

Locations

1 site across 1 country: United States