An Hydro-Mechanical Model of Edema Formation Applied to Bacterial Myocarditis

In young adults, up to 20% of all cases of sudden death are due to myocarditis, a heart disease caused by inflammation in the myocardium. There are several reasons that lead to myocarditis, including infections caused by a virus, bacteria, protozoa, fungus, and others. Additionally, this inflammatory response is one of the consequences of an infection triggered by an immunological reaction, which causes an edema in the heart. One of the techniques used to visualize myocardial edema is the cardiovascular magnetic resonance of myocardial tissue. Using this imaging exam it is possible to visualize hyperintense signal in the edematous zone. This paper aims to model and simulate the mechanical deformation due to a bacterial infection in a two-dimensional domain that represents a short axis slice of the heart and compares qualitatively the results with data found from literature. This mathematical model consists of partial differential equations (PDEs) that use the Biot theory of poroelasticity applied to living tissue and coupled with an immune system dynamics to model the edema formation. Thus, the mathematical model used in this study is basically divided into two parts: one modelling the immune system response due to a bacterial infection, represented by neutrophils; and another representing the hydro-mechanical problem. The preliminary results show that our model is able to reproduce some key aspects related to an initial myocarditis.