Association of QRS Notch Resolution During LV-Only Fusion Pacing With Early Left Ventricular Reverse Remodeling After...

Area of Science:

• Cardiology
• Electrophysiology
• Heart Failure Management

Background:

• Cardiac resynchronization therapy (CRT) is vital for heart failure patients with left bundle branch block (LBBB).
• However, a significant portion of patients do not respond to CRT.
• Early identification of effective electrical resynchronization is crucial for improving patient outcomes.

Purpose of the Study:

• To assess the association between V5-V6 R-wave notching/slurring resolution during left ventricular-only pacing (LV-only pacing) and early left ventricular reverse remodeling.
• To determine if a high percentage of LV-only pacing at one month is linked to improved remodeling.
• To identify predictors of successful early reverse remodeling in complete LBBB (CLBBB) patients undergoing CRT.

Main Methods:

• Retrospective analysis of 49 CLBBB patients undergoing CRT.
• Classification into 'R-Notch Resolution' (n=15) and 'Non-R-Notch Resolution' (n=34) groups based on ECG findings and LV-only pacing percentage (≥50% at 1 month).
• Primary endpoint: ≥15% reduction in left ventricular end-systolic volume (LVESV) at 1 month, indicating reverse remodeling.

Main Results:

• The R-Notch Resolution group showed significantly higher rates of 1-month reverse remodeling (80.0% vs. 47.1%).
• Multivariable logistic regression confirmed that R-Notch Resolution group status was an independent predictor of early reverse remodeling.
• These findings highlight the prognostic value of specific ECG changes during LV-only pacing.

Conclusions:

• Resolution of V5-V6 R-wave notching/slurring during LV-only pacing, coupled with ≥50% LV-only pacing at 1 month, is independently associated with early reverse remodeling post-CRT.
• This ECG marker can help clinicians identify patients likely to benefit from CRT sooner.
• Optimizing pacing strategies based on these early indicators may enhance CRT efficacy.