Simbios Talk by Ellen Kuhl, Stanford University, April 23, 2008

Title: SimGrowth - A  virtual lab for myocardial infarction

This presentation illustrates our first attempts towards the computational modeling of cardiac disease. An estimated 79,400,000 American adults, one in three, have one or more types of cardiovascular disease generating an annual health care cost of $431.8 billion. A typical example is myocardial infarction which manifests itself clinically in disproportionate thinning and dilatation of the infarct region accompanied by distortion in size and shape of the entire heart. Historically, therapies for cardiac disease have been developed by trial and error rather than by trying to understand the functional and structural changes of the damaged tissue.

Supported through a SIMBIOS seed grant, we are developing novel continuum theories and related computational tools that provide greater insight into the complex pathways of myocardial infarction and guide the design of new post-infarction therapies. To characterize the short-term response of the actively beating heart, excitation-contraction coupling has been accounted for through the FitzHugh-Nagumo equations for electrophysiology in addition to the mechanical equilibrium problem. The long-term response of ventricular growth and remodeling is modeled constitutively through the introduction of a growth tensor that can account for both ventricular hypertrophy and dilation.

After illustrating first results of the excitation-contraction coupling and growth simulations, we demonstrate how the computational models will be verified experimentally in the future. To do so, we propose to explore cardiac tissue on three different scales, on the cellular, on the tissue and on the organ level.