Figure 9
From: In vivo assessment of mitral valve leaflet remodelling following myocardial infarction

Uniaxial schematic of MV leaflet configurations that were considered in the present study, with red curves depicting how the collagen fibre geometry within the tissue would evolve with stretch (not to scale). Reference lengths for pre-MI diastole (\(L_\text {dia,pre}\)), post-MI diastole (\(L_\text {dia,post}\)), and systole (\(L_\text {sys}\)) are labelled, as well as systolic stretches with respect to pre-MI and post-MI diastolic configurations (\(\lambda _\text {pre}\) and \(\lambda _\text {post}\), respectively). Note that \(L_\text {dia,post} > L_\text {dia,pre}\) and a constant \(L_\text {sys}\) imply that \(\lambda _\text {post} < \lambda _\text {pre}\), even in the absence of active remodelling in the collagen fibre network. Our results (especially Fig. 4a) thus suggest that active remodelling over the 8-week study period was not sufficient to effect substantial changes in the mechanical properties of the tissue. Equivalently, the apparent tissue stiffening observed over most of the leaflet (Figs. 4b, 10b) can be explained as a passive consequence of the MI-induced diastolic deformations (Fig. 3).