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Adjusting the timing of left-ventricular pacing using electrocardiogram and device electrograms
Yaariv Khaykin1, Derek Exner, David Birnie
1Southlake Regional Health Centre, Newmarket, ON, Canada.
Summary
Optimizing atrio-ventricular (AV) delays during left-ventricular (LV) pacing in cardiac resynchronization therapy (CRT) can be approximated using intrinsic AV conduction time. This method improves LV function, similar to bi-ventricular (BiV) pacing.
Area of Science:
- Cardiology
- Biomedical Engineering
- Electrophysiology
Background:
- Cardiac resynchronization therapy (CRT) aims to improve cardiac function in heart failure patients.
- Left-ventricular (LV) pacing is an alternative to bi-ventricular (BiV) pacing in select CRT patients.
- Optimizing atrio-ventricular (AV) timing is crucial for CRT efficacy.
Purpose of the Study:
- To determine if optimal device AV delays during LV pacing can be predicted.
- To investigate the correlation between optimal AV delays and electrocardiogram (ECG) intervals.
- To compare the efficacy of optimized LV pacing with BiV pacing.
Main Methods:
- Fifty-five CRT patients in sinus rhythm with preserved AV conduction were studied.
- Devices were programmed for LV pacing with varying AV delays and for BiV pacing.
- Echocardiography assessed LV ejection fraction (LVEF) and LV end-systolic volume (LVESV) at each setting.
Main Results:
- Optimal AV delays during LV pacing moderately correlated with the intrinsic atrial pacing to right-ventricular sensing (Ap-RVs) interval.
- The strongest correlation (R=0.66) was between optimal AV delay and the Ap-RVs interval.
- Programming AV delays to 70% of the intrinsic Ap-RVs interval or Ap-RVs-40 ms significantly improved LV function.
Conclusions:
- Optimal AV delay during LV pacing can be approximated using intrinsic AV conduction time.
- This predictive method offers significant LV function improvement comparable to BiV pacing.
- The intrinsic Ap-RVs interval is a key predictor for optimizing AV timing in LV pacing.
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