Related Experiment Video
Updated: Jun 27, 2026
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
Mechanical analysis of congestive heart failure caused by bundle branch block based on an electromechanical canine
Jianhong Dou1, Ling Xia, Yu Zhang
1Department of Biomedical Engineering, Zhejiang University, Hangzhou 310027, People's Republic of China. Guangzhou General Army Hospital, Guangzhou 510010, People's Republic of China.
Insights
Bundle branch block (BBB) impairs heart function by causing asynchronous electrical activation. This study used a 3D electromechanical model to simulate BBB, revealing significant mechanical dyssynchrony and increased septal stress, offering insights into heart failure.
Area of Science:
- Cardiovascular Physiology
- Computational Biology
- Medical Imaging
Background:
- Bundle branch block (BBB) leads to asynchronous electrical activation, potentially reducing ventricular function.
- Experimental assessment of BBB's mechanical effects is challenging.
- Existing cardiac models primarily focus on electrophysiology, neglecting mechanical aspects of BBB.
Purpose of the Study:
- To investigate the mechanical function and asynchrony in the heart during complete left and right bundle branch block (LBBB and RBBB).
- To utilize a three-dimensional electromechanical canine heart model for simulating BBB.
- To provide quantitative estimates of ventricular wall strain and stress in BBB.
Main Methods:
- Reconstructed a dog heart's anatomy and fiber orientations from MRI and DT-MRI data.
- Simulated asynchronous excitation propagation and conduction using reaction-diffusion equations and parallel computation.
- Employed the finite-element method to compute myocardial mechanics and quantify asynchrony, strain, and stress.
Main Results:
- Simulations revealed inter- and intraventricular systolic dyssynchrony in BBB.
- Right bundle branch block (RBBB) demonstrated potentially better left ventricular (LV) systolic function and synchrony compared to LBBB.
- Ventricles consistently moved towards the early-activated ventricle, and the septum experienced higher stress than free walls.
Conclusions:
- The electromechanical model successfully simulated mechanical asynchrony and validated clinical findings.
- BBB induces significant mechanical dyssynchrony and altered ventricular dynamics.
- This modeling approach offers a valuable tool for understanding the mechanical implications of BBB-induced congestive heart failure (CHF).
Abstract:
Asynchronous electrical activation, induced by bundle branch block (BBB), can cause reduced ventricular function. However, the effects of BBB on the mechanical function of heart are difficult to assess experimentally. Many heart models have been developed to investigate cardiac properties during BBB but have mainly focused on the electrophysiological properties. To date, the mechanical function of BBB has not been well investigated. Based on a three-dimensional electromechanical canine heart model, the mechanical properties of complete left and right bundle branch block (LBBB and RBBB) were simulated. The anatomical model as well as the fiber orientations of a dog heart was reconstructed from magnetic resonance imaging (MRI) and diffusion tensor MRI (DT-MRI). Using the solutions of reaction-diffusion equations and with a strategy of parallel computation, the asynchronous excitation propagation and intraventricular conduction in BBB was simulated. The mechanics of myocardial tissues were computed with time-, sarcomere length-dependent uniaxial active stress initiated at the time of depolarization. The quantification of mechanical intra- and interventricular asynchrony of BBB was then investigated using the finite-element method with an eight-node isoparametric element. The simulation results show that (1) there exists inter- and intraventricular systolic dyssynchrony during BBB; (2) RBBB may have more mechanical synchrony and better systolic function of the left ventricle (LV) than LBBB; (3) the ventricles always move toward the early-activated ventricle; and (4) the septum experiences higher stress than left and right ventricular free walls in BBB. The simulation results validate clinical and experimental recordings of heart deformation and provide regional quantitative estimates of ventricular wall strain and stress. The present work suggests that an electromechanical heart model, incorporating real geometry and fiber orientations, may be helpful for better understanding of the mechanical implications of congestive heart failure (CHF) caused by BBB.
Related Concept Videos
01:29Heart Failure II: Pathophysiology
01:30Cardiomyopathy II: Dilated Cardiomyopathy
01:26Imbalances in Cardiac Output
CHF can occur due to the failure of either side of the heart. Left-side failure leads to pulmonary congestion—the right side continues to send blood...