Adaptive Cardiac Resynchronization Therapy in Patients With RBBB
Right Bundle-Branch Block
About this trial
This is an interventional diagnostic trial for Right Bundle-Branch Block
Eligibility Criteria
Inclusion Criteria: Included patients will have: sinus rhythm or isolated atrial pacing LV systolic dysfunction (EF <35% at time of device implant) AV conduction <250 ms, RBBB, and have an implanted CRT device based on the ACC/AHA/HRS guidelines (2, 18) or will have a CRT device implanted during the study enrollment per ACC/AHA/HRS guidelines (2). Exclusion Criteria: atrial fibrillation atrial flutter atrial tachycardia AV delay > 250 ms sinus tachycardia with resting heart rate at time of the study 100 bpm frequent APCs (> 25% of the total beats/min) or PVCs (>20% of the total beats/min), or patients with EF > 40% at time of enrollment (if LV systolic function was found to be improved from time of implant).
Sites / Locations
- Central Arkansas Veterans Healthare System
- Henry Ford Hospital
Arms of the Study
Arm 1
Other
CRT Optimization
Each patient will have atrial pacing 10% higher than the sinus rate or atrial pacing at a rate of 60 bpm if significant sinus bradycardia is present. Each patient will have six ECGs and echocardiographic sequences performed in the same session. In addition six electrical activation evaluations by the Medtronic ECG belt will be done as well. The first study will always be with no ventricular pacing. One study will be echocardiography-optimized BIV pacing and four studies for echocardiography-optimized (?) adaptive RV-only pacing with different AV intervals. A random-sequence will be performed to determine the order for the rest of the studies.