Remodelling potential of the mitral heart valve leaflet

Little is known about how normal valvular tissues grow and remodel in response to altered loading. In the present work, we used the pregnancy state to represent a non-pathological cardiac volume overload that distends the mitral valve (MV), utilizing both extant and new experimental data and a modified form of our MV structural constitutive model. We determined that there was an initial period of permanent set-like deformation where no remodelling occurs, followed by a remodelling phase which resulted in near-complete restoration of homeostatic tissue-level behaviour. In addition, we observed that changes in the underlying MV interstitial cell (MVIC) geometry closely paralleled the tissue-level remodelling events, undergoing an initial passive perturbation followed by a gradual recovery to the pre-pregnant state. Collectively, these results suggest that valvular remodelling is actively mediated by average MVIC deformations (i.e. not cycle to cycle, but over a period of weeks).