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High Left Ventricular Lead Sensing Delay Predicts QRS Narrowing and Good Response to Cardiac Resynchronization
Onur Kaypakli1, Mevlüt Koç1, Gökhan Gözübüyük1
1Department of Cardiology, University of Health Sciences, Adana Health Practices and Research Center, Adana, Turkey.
Insights
Left ventricular lead sensing delay is a key predictor of successful cardiac resynchronization therapy (CRT) response in heart failure patients. This metric helps identify individuals likely to benefit from CRT, improving treatment outcomes.
Area of Science:
- Cardiology
- Electrophysiology
- Heart Failure Management
Background:
- Cardiac resynchronization therapy (CRT) improves heart failure (HF) prognosis, but patient response varies.
- Optimizing left ventricular (LV) lead placement is crucial for enhancing CRT efficacy.
- Identifying predictors of CRT response is essential for patient selection and treatment optimization.
Purpose of the Study:
- To investigate the relationship between LV lead sensing delay and echocardiographic and electrocardiographic responses to CRT.
- To determine if LV lead sensing delay can predict favorable outcomes in patients undergoing CRT.
Main Methods:
- Prospective study of 156 HF patients with specific criteria (QRS ≥ 120 ms, LBBB, NYHA II-IV, LVEF < 35%) scheduled for CRT.
- Echocardiographic CRT response defined as ≥15% reduction in LV end-systolic volume (LVESV).
- LV lead sensing delay calculated as the time from QRS onset to LV lead depolarization.
Main Results:
- LVESV reduction correlated with baseline QRS width, QRS narrowing, and LV lead sensing delay.
- LV lead sensing delay was the sole independent predictor of significant LVESV reduction in logistic regression.
- LV lead sensing delay also showed significant associations with increased LVEF and QRS narrowing.
Conclusions:
- LV lead sensing delay is the only independent predictor of significant LVESV reduction after CRT.
- LV lead sensing delay is significantly associated with improved LVEF and QRS narrowing.
- LV lead sensing delay may serve as a valuable marker for predicting favorable CRT response.
Background:
Cardiac resynchronization therapy (CRT) was shown to improve heart failure (HF) prognosis. But many patients do not benefit from CRT. Optimization of left ventricular (LV) lead position to the latest activated LV area is important to increase CRT response. We aimed to detect the relationship between LV lead sensing delay and echocardiographic and electrocardiographic response to CRT treatment.
Methods:
We prospectively included 156 consecutive patients with HF diagnosis, QRS ≥ 120 ms, left bundle branch block, New York Heart Association II-IV, LV ejection fraction (LVEF) < 35%, and scheduled for CRT (100 male, 56 female; mean age 65.8 ± 10.06 years). Echocardiographic CRT response was defined as ≥15% reduction in LV end-systolic volume (LVESV). LV lead sensing delay was calculated as the time interval from the onset of surface QRS wave to the onset of depolarization wave recorded from the LV lead by using the LV pacing lead as a bipolar electrode.
Results:
LVESV reduction was associated with baseline QRS width (r = 0.292, P = 001), QRS narrowing (r = 0.332, P < 001), and LV lead sensing delay (r = 0.454, P < 001) in bivariate analysis. In logistic regression analysis, LV lead sensing delay was found to be the only independent parameter for predicting significant LVESV reduction (β = 0.423, P < 0.001). LV lead sensing delay was also found to be significantly associated with LVEF increase (r = 0.320, P < 0.001) and QRS narrowing (r = 0.345, P < 0.001).
Conclusion:
LV lead sensing delay is the only independent predictor for significant reduction in LVESV and was found to be significantly associated with LVEF increase and QRS narrowing after CRT treatment. We suggest that LV lead sensing delay may be used as a marker to predict the favorable response to CRT.
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