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Updated: Oct 25, 2025

Benefits of Cardiac Resynchronization Therapy in an Asynchronous Heart Failure Model Induced by Left Bundle Branch Ablation and Rapid Pacing
12:45

Benefits of Cardiac Resynchronization Therapy in an Asynchronous Heart Failure Model Induced by Left Bundle Branch Ablation and Rapid Pacing

Published on: December 11, 2017

10.6K

Lower rate limit for pacing by cardiac resynchronization defibrillators: Should lower rate programming be

Arjun D Sharma1, Bruce L Wilkoff2, Mark Richards3

  • 1Unafiliated, Reno, Nevada.

Heart Rhythm
|August 9, 2021
PubMed

Insights

Lower heart rate limit programming in cardiac resynchronization therapy-defibrillators (CRT-Ds) is linked to better survival. This association holds true across different heart rate scores, suggesting a significant impact on patient outcomes.

Area of Science:

  • Cardiology
  • Biomedical Engineering
  • Clinical Research

Background:

  • Large-scale real-world data linking lower rate limit (LRL) programming and survival in cardiac resynchronization therapy-defibrillator (CRT-D) patients is lacking.
  • Understanding factors influencing CRT-D patient outcomes is crucial for optimizing device therapy.

Purpose of the Study:

  • To test the hypothesis that lower LRL programming is independently associated with improved survival in CRT-D patients.
  • To investigate the association between LRL and heart rate score (HrSc) in this population.

Main Methods:

  • Analysis of a large database (ALTITUDE) of dual-chamber CRT-D devices implanted between 2006-2011.
  • Definition of baseline heart rate score (HrSc) based on the tallest 10-beat histogram bin.
  • Assessment of LRL during remote patient monitoring (RPM) uploads.
  • Multivariable Cox proportional hazards modeling to evaluate associations between LRL, survival, HrSc, and other variables.

Main Results:

  • The study included 61,881 subjects with a mean follow-up of 2.9 years.
  • Lower LRL programming was independently associated with younger age, less atrial fibrillation, female sex, and lower HrSc.
  • Lower LRL was significantly associated with improved survival, with LRL of 40 bpm showing the greatest survival benefit across all HrSc subgroups.
  • A significant interaction was observed between HrSc and LRL, with the most pronounced survival differences noted at LRL of 40 bpm.

Conclusions:

  • Lower LRL programming and lower HrSc are associated and both linked to improved survival in a large cohort of CRT-D patients.
  • The observed relationships between survival, LRL programming, and HrSc warrant further investigation to refine therapeutic strategies.
Abstract

Keywords:
Cardiac resynchronizationHeart rate scoreLower rate limitPacingRisk factorsSurvival

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