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Randomized prospective trial of atrioventricular delay programming for cardiac resynchronization therapy
Navinder S Sawhney1, Alan D Waggoner, Sanjeev Garhwal
1Cardiovascular Division, Washington University, School of Medicine, St. Louis, Missouri 63110, USA.
Heart Rhythm
|April 27, 2005
Summary
Optimizing the atrioventricular (AV) delay using Doppler echocardiography in cardiac resynchronization therapy (CRT) significantly improves heart failure outcomes. This method is clinically superior to standard empiric programming for patients with severe heart failure.
Area of Science:
- Cardiology
- Biomedical Engineering
- Clinical Trials
Background:
- The clinical impact of atrioventricular (AV) delay programming on patient outcomes following cardiac resynchronization therapy (CRT) remains largely undetermined.
- Optimizing AV delay is crucial for maximizing the efficacy of CRT in patients with heart failure.
Purpose of the Study:
- To evaluate whether optimizing AV delay using continuous-wave Doppler aortic velocity-time integral (VTI) offers superior clinical benefits compared to an empiric AV delay in CRT patients.
- To assess the impact of AV delay optimization on New York Heart Association (NYHA) functional classification and quality-of-life (QOL) scores.
Main Methods:
- A randomized, prospective, single-blind trial involving 40 severe heart failure patients undergoing CRT.
- Patients were assigned to either optimized AV delay via Doppler echocardiography (measuring aortic VTI) or a fixed empiric AV delay of 120 ms.
- Outcomes, including NYHA class and QOL, were compared at 3 months post-randomization.
Main Results:
- Optimized AV delay (Group 1) showed immediate improvements in VTI (4.0 cm vs 1.8 cm) and ejection fraction (7.8% vs 3.4%) compared to empiric delay (Group 2).
- After 3 months, Group 1 experienced significantly greater improvements in NYHA classification (1.0 vs 0.4 points) and QOL scores (23 vs 13 points).
Conclusions:
- Echocardiography-guided AV delay optimization, utilizing aortic Doppler VTI, leads to improved clinical outcomes in CRT patients.
- This optimized approach demonstrates superiority over a standard empiric AV delay of 120 ms at the 3-month follow-up.