Atrioventricular Block, Conduction System Pacing
Conditions
Keywords
Atrioventicular Block, Atrioventricular Delay Optimization, Conduction System Pacing, Global Longitudinal Strain, Mechanical Resynchronization, Ventricular Function
Brief summary
Conduction system pacing has emerged as a physiological pacing strategy that preserves ventricular electrical activation and minimizes pacing-induced dyssynchrony. However, the optimal atrioventricular delay setting in patients undergoing conduction system pacing remains uncertain. This study aims to evaluate the effects of individualized echocardiography-guided atrioventricular delay optimization on ventricular function and hemodynamic performance in patients with conduction system pacing. Echocardiographic parameters including global longitudinal strain, left ventricular ejection fraction, left ventricular outflow tract velocity-time integral, cardiac output, and diastolic function indices will be assessed before and after atrioventricular delay optimization. The study will investigate whether optimization of atrioventricular timing provides additional mechanical and hemodynamic benefits beyond physiological ventricular activation achieved by conduction system pacing alone.
Detailed description
Conduction system pacing (CSP), including His bundle pacing and left bundle branch area pacing, has emerged as a physiological pacing strategy capable of preserving ventricular electrical activation and reducing pacing-induced dyssynchrony. Compared with conventional right ventricular pacing, CSP has been associated with improved electrical synchrony, ventricular function, and clinical outcomes. Despite restoration of physiological ventricular activation, optimal atrioventricular (AV) coupling remains essential for maximizing ventricular filling, stroke volume, and overall cardiac performance. Inadequate AV timing may impair diastolic filling, reduce atrial contribution to ventricular preload, and limit the hemodynamic benefits achieved by physiological pacing. While AV delay optimization has been extensively investigated in cardiac resynchronization therapy, data regarding its role in patients undergoing CSP remain limited. The present study evaluates the impact of individualized echocardiography-guided AV delay optimization on ventricular mechanical performance and hemodynamic parameters in patients with CSP implanted for atrioventricular block. Comprehensive transthoracic echocardiographic assessment will be performed before and after AV delay optimization. Measurements include left ventricular ejection fraction, global longitudinal strain, left ventricular outflow tract velocity-time integral, cardiac output, chamber dimensions, pulmonary artery systolic pressure, and diastolic function parameters. The primary objective is to determine the effect of AV delay optimization on global longitudinal strain. Secondary objectives include assessment of changes in left ventricular systolic function, hemodynamic performance, and diastolic parameters. The study aims to provide additional evidence regarding the importance of individualized AV programming in patients undergoing conduction system pacing.
Interventions
DEVICEEchocardiography-Guided Atrioventricular Delay Optimization
Atrioventricular delay settings are individually optimized using echocardiographic assessment of transmitral inflow and ventricular filling patterns. Device programming is adjusted to achieve optimal atrioventricular coupling and ventricular performance.
Sponsors
Bursa Yuksek Ihtisas Training and Research Hospital
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE
Intervention model description
This is a prospective, single-center, single-group interventional study. All enrolled participants with conduction system pacing undergo individualized echocardiography-guided atrioventricular delay optimization. Ventricular function and hemodynamic parameters are evaluated before and after optimization using transthoracic echocardiography. Each participant serves as his or her own control for outcome assessment.
Eligibility
Sex/Gender
ALL
Age
18 Years to 80 Years
Healthy volunteers
No
Inclusion criteria
* Age between 18 and 80 years * Permanent conduction system pacing implantation for atrioventricular block * At least 1 month elapsed since device implantation * Sinus rhythm at the time of enrollment * Left ventricular ejection fraction \>40% * Adequate echocardiographic image quality for comprehensive assessment * Ability and willingness to provide informed consent
Exclusion criteria
* Permanent or persistent atrial fibrillation * Significant valvular heart disease * Active malignancy * Severe systemic illness with limited life expectancy * Sinus node dysfunction requiring alternative pacing strategies * Inadequate echocardiographic image quality * Inability to comply with study procedures * Refusal to participate in the study
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Global Longitudinal Strain (GLS) | Immediately before and immediately after atrioventricular delay optimization. | Assessment of left ventricular global longitudinal strain using two-dimensional speckle tracking echocardiography before and after atrioventricular delay optimization. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Left Ventricular Outflow Tract Velocity-Time Integral (LVOT VTI) | Immediately before and immediately after atrioventricular delay optimization. | Assessment of forward stroke volume using pulsed-wave Doppler measurements at the left ventricular outflow tract. |
| Left Ventricular Ejection Fraction (LVEF) | Immediately before and immediately after atrioventricular delay optimization. | Assessment of left ventricular systolic function using the biplane Simpson method. |
Countries
Turkey (Türkiye)
Contacts
STUDY_CHAIRAhmet Tütüncü
Bursa Yuksek Ihtisas Training and Research Hospital
Outcome results
None listed