Benefits of Cardiac Resynchronization Therapy in an Asynchronous Heart Failure Model Induced by Left Bundle Branch Ablation and Rapid Pacing
December 11th, 2017
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The establishment of a chronic asynchronous heart failure (HF) model by rapid pacing combined with left bundle branch ablation is presented. Two-dimensional speckle tracking imaging and aortic velocity time integral are applied to validate this stable HF model with left ventricular asynchrony and the benefits of cardiac resynchronization therapy.
Overview
This article presents a method for establishing a chronic asynchronous heart failure (HF) model using rapid pacing and left bundle branch ablation. The model is validated through two-dimensional speckle tracking imaging and aortic velocity time integral, demonstrating the benefits of cardiac resynchronization therapy.
Key Study Components
Area of Science
- Cardiology
- Heart Failure
- Cardiac Resynchronization Therapy
Background
- Chronic heart failure is a significant health issue.
- Cardiac resynchronization therapy (CRT) can improve heart function.
- Asynchronous heart failure models are essential for studying CRT.
- Left bundle branch ablation is a key technique in this model.
Purpose of Study
- To establish a stable chronic asynchronous heart failure model.
- To evaluate the effects of cardiac resynchronization therapy.
- To utilize echocardiographic parameters and biological modifications for validation.
Methods Used
- Rapid pacing combined with left bundle branch ablation.
- Two-dimensional speckle tracking imaging for assessment.
- Aortic velocity time integral measurement.
- Epicardial left ventricle lead implantation technique.
Main Results
- Successful establishment of a chronic asynchronous heart failure model.
- Validation of the model through imaging techniques.
- Demonstration of CRT benefits in the model.
- Insights into the biological modifications associated with HF.
Conclusions
- The method provides a valid approach for HF research.
- It highlights the importance of left bundle branch ablation.
- This model can facilitate future studies on CRT efficacy.
Frequently Asked Questions
What is the significance of the left bundle branch ablation?
Left bundle branch ablation prevents recovery of cardiac function, allowing for a stable heart failure model.
How is the heart failure model validated?
Validation is achieved through two-dimensional speckle tracking imaging and aortic velocity time integral measurements.
What are the benefits of cardiac resynchronization therapy?
CRT can improve heart function and quality of life in patients with heart failure.
What techniques are used in this study?
The study employs rapid pacing, left bundle branch ablation, and echocardiographic assessments.
Who performed the epicardial left ventricle lead implantation?
The implantation was performed by technician Yao Ruiming, an expert in the procedure.
What is the overall goal of this experiment?
To describe a feasible method for establishing a chronic asynchronous heart failure model for studying CRT benefits.
Executive Industry Relevance
Establishing a stable asynchronous heart failure model with isolated left bundle branch block is critical for evaluating cardiac resynchronization therapy efficacy in preclinical research. This model enables mechanistic de-risking of CRT by providing a reproducible platform to assess structural and functional reverse remodeling. It supports target validation and predictive confidence in early discovery stages for HF therapeutics.
Strategic Applications in Biopharma R&D
Early Discovery & Target Validation
- Scientific Value: Enables interrogation of therapeutic hypotheses related to ventricular synchrony and myocardial recovery pathways.
- Operational Value: Provides a stable disease model with persistent LBBB to avoid functional recovery confounders during CRT evaluation.
- Predictive Value: Supports assessment of CRT-induced reverse remodeling through quantifiable echocardiographic and histologic endpoints.
Screening & Assay Development
- Assay Readiness: Generates validated biological systems with measurable LV asynchrony and dysfunction for downstream compound or device testing.
- Quantitative Outputs: Produces reliable readouts including two-dimensional speckle tracking strain dispersion and aortic velocity time interval for objective functional assessment.
- Reproducibility: Establishes a chronic stable HF model suitable for longitudinal studies and cross-lab standardization.
Translational & Preclinical Research
- Disease Relevance: Models chronic HF with isolated LBBB, reflecting a key patient subpopulation predictive of CRT response.
- Translational Continuity: Links functional improvements (LV volumes, ejection fraction) to histologic reverse remodeling (cardiomyocyte diameter, collagen volume fraction).
- Risk-Adjusted Advancement: Enables evaluation of CRT benefits on both structural and molecular remodeling to inform go/no-go decisions.
Pipeline & Workflow Integration
The method integrates into the discovery continuum from target validation through lead identification to preclinical evaluation by providing a stable model for assessing device-based therapies.
- Discovery Biology: Supports hypothesis testing on ventricular activation patterns and mechanical dyssynchrony as drivers of HF progression.
- Screening: Delivers assay-ready systems with standardized LV asynchrony metrics for consistent intervention testing.
- Analytics: Enables quantitative comparison of intervention effects using speckle tracking-derived strain timing and aortic flow integrals.
- Translational Research: Connects acute functional improvements to chronic structural recovery, supporting biomarker-aligned preclinical validation.
- Enterprise Reuse: Establishes a reusable preclinical platform for iterative CRT parameter optimization and combination therapy screening.
Operational & Enterprise Impact
- Scientific Value: Reduces mechanistic ambiguity in CRT response by isolating LBBB as a key variable in HF pathogenesis.
- Operational Value: Ensures model stability over eight weeks, enabling sustained intervention studies without functional recovery confounds.
- Strategic Value: Improves go/no-go decision confidence by demonstrating CRT effects on both functional and histologic remodeling endpoints.
- Portfolio Impact: Facilitates risk-adjusted prioritization of CRT-related interventions based on validated reverse remodeling outcomes.
Implementation Considerations
- Requires expertise in cardiac surgery, lead implantation, and radiofrequency ablation techniques in large animal models.
- Dependent on fluoroscopy-capable electrophysiology labs and echocardiographic imaging systems with speckle tracking functionality.
- Necessitates standardized postoperative care and anticoagulation protocols to maintain lead stability and prevent thrombotic complications.
- Involves adaptation considerations when translating ablation parameters across species or disease etiologies.
- Limited by the technical complexity of epicardial lead placement and dual-chamber pacing system implantation.
Biopharma FAQs
Why does left bundle branch ablation prevent cardiac function recovery?
Left bundle branch ablation eliminates native ventricular conduction, preventing functional recovery during sustained rapid pacing and enabling a stable heart failure model for CRT evaluation.
How does independent variable isolation improve target validation in HF models?
Isolating LBBB via ablation allows researchers to assess CRT effects on a defined electrophysiological substrate, reducing confounding variables in target validation studies.
What quantitative dependent variable measurements enable CRT benefit assessment?
Two-dimensional speckle tracking imaging quantifies longitudinal strain dispersion to measure mechanical dyssynchrony, while aortic velocity time integral assesses stroke volume and pump function following CRT.
Why do replication requirements matter for cross-functional collaboration in preclinical HF studies?
Replication ensures consistent LV asynchrony and dysfunction across studies, enabling reliable comparison of CRT outcomes between discovery, translational, and preclinical teams.
What statistical analysis capabilities are required before implementing this HF model?
Implementation requires capacity for longitudinal analysis of echocardiographic endpoints and histologic metrics, with appropriate power calculations to detect CRT-induced reverse remodeling effects.
Chapters in this video
0:05
Title
1:16
Epicardial LV Pacing Electrode Implantation
3:11
RA and RV Pacing Electrode Implantation
5:23
Pulse Generator Implantation
6:40
Right-sided His Bundle and Left Bundle Branch (LBB) Potentials and LBB Ablation
10:07
Results: Measurables Gain from Cardiac Resynchronization Therapy (CRT)
11:54
Conclusion
