Modeling Shear Stress during Cardiac Valve Formation

Developmental heart defects are the most common birth defects and heart valve defects are the most common cardiac defects. Therefore, defining the mechanisms of cardiac valve development is critical to our understanding and treatment of these debilitating disorders. At the early stages of cardiac development the heart is a simple two-cell layered tube, which divides into separate atrial and ventricular regions. The area between the atria and ventricles is called the atrioventricular (AV) canal and is the site of future AV valve formation. Early in the formation of cardiac valves, small, mound-like structures, called cushions, form. As valve development continues, these mounds fuse and thin into valve leaflets.

Our group has previously described an in vitro model of valve leaflet development. A longstanding hypothesis proposes that mechanical forces, such as shear stress, are critical in shaping the cushions into leaflets. We are currently using our in vitro model system to test this hypothesis. As part of this investigation, we sought to mathematically model the key force, shear stress, which occurs in our in vitro model system using the COMSOL engineering program. The shear stress values obtained from this model will then be compared to values obtained from prior experimental quantification in the developing chick heart.