Virtual Tools for Cardiac Remodeling
EMSL Project ID
18404
Abstract
Congestive heart failure (CHF) afflicts 5 million people in the US with 550,000 new cases each year, at an annual cost of almost $29 billion. In 2001, CHF was the primary cause of 1 million hospitalizations and contributed to over 266,000 deaths . One of the major causes of CHF is infarction-induced ventricular remodeling, where tissue integrity following an infarction is deleteriously altered over time. Currently, there is no means for visualizing such alterations.The overall goal of this project is the development and validation of a biophysics simulation-based methodology for estimating regional systolic myocardial material properties, by treating the myocardium as a slowly-varying continuum and characterizing regionally specific three-dimensional constitutive relationships that capture passive and active tissue components, calcium concentration, sarcomere length, and time. Such an approach would be of great value in the design and evaluation of new surgical and medical strategies to treat and/or prevent infarction-induced ventricular remodeling. Once the field of constitutive properties for the myocardium has been established, the effect of therapeutic changes on regional geometry (i.e., surgical remodeling) and/or material properties (i.e., medicine, gene therapy, cell therapy) can be evaluated and the success or failure of a proposed therapy predicted. With clinical experience, such information could be used as a diagnostic modality to risk stratify patients early after a myocardial infarction who are at risk for adverse remodeling and the development of heart failure.
The simulation-based approach is based on the conservation laws of continuum mechanics and implemented using the finite element (FE) method. To account for large-deformation and internal forces that depend on peak intracellular calcium concentration, sarcomere length, and time, appropriate constitutive relations must be developed that are based on rigorous principles of computational physics. Moreover, the material heterogeneity of the heart and surrounding tissues implies a very large parameter space, resulting in a computationally intensive problem. To characterize these material relationships, simulations will target clinical and research data to be acquired at the Veteran?s Hospital in San Francisco. Such data will include magnetic resonance diffusion tensor imaging, contrast-enhanced magnetic resonance proton, dynamic tagged magnetic resonance strain data, and cardiac catheter data. The specific focus of this EMSL User Proposal will be 1) to develop a computational model of the human left ventricle that can be run on a distributed architecture, 2) to use a family of such simulations to characterize tissue heterogeneity in the heart via a semi-global nonlinear optimization strategy , and 3) to coordinate the results of these simulations with our university partners at the University of California Berkeley, and at the University of California San Francisco.
Project Details
Project type
Exploratory Research
Start Date
2006-04-01
End Date
2007-03-16
Status
Closed
Released Data Link
Team
Principal Investigator