Biomechanical evaluation of the pathophysiologic developmental mechanisms of mitral valve prolapse: effect of valvular morphologic alteration

Abstract

Mitral valve prolapse (MVP) refers to an excessive billowing of the mitral valve (MV) leaflets across the mitral annular plane into the left atrium during the systolic portion of the cardiac cycle. The underlying mechanisms for the development of MVP and mitral regurgitation (MR) in association with MV tissue remodeling is still unclear. We performed computational MV simulations to investigate the pathophysiologic developmental mechanisms of MVP. A parametric MV geometry model was utilized for this study. Posterior leaflet enlargement and posterior chordal elongation models were created by adjusting the geometry of the posterior leaflet and chordae, respectively. Dynamic finite element simulations of MV function were performed over the complete cardiac cycle. Computational simulations demonstrated that enlarging posterior leaflet area increased large stress concentration in the posterior leaflets and chordae, and posterior chordal elongation decreased leaflet coaptation. When MVP was accompanied by both posterior leaflet enlargement and chordal elongation simultaneously, the posterior leaflet was exposed to extremely large prolapse with a substantial lack of leaflet coaptation. These data indicate that MVP development is closely related to tissue alterations of the leaflets and chordae. This biomechanical evaluation strategy can help us better understand the pathophysiologic developmental mechanisms of MVP.

New insights into mitral heart valve prolapse after chordae rupture through fluid–structure interaction computational modeling

“…In the chordae rupture models where partial or total double scallop prolapse occurred, overall, a high-stress concentration was found in the prolapsed PML segment when compared to the control model. Our simulation results seem to agree with previous computational studies that have compared MV stresses under chordae rupture and normal/repaired states 9 , 35 , 36 . For example, Kunzelman et al .…”

Geometric description for the anatomy of the mitral valve: A review

“…In reality, for a human MV model representation, it is common mathematically to simplify the shape of the PMs, as well as chordae insertion patterns: some studies represent the PM tips as unique 3D points where all chordae insert, as previously mentioned (Cochran and Kunzelman, 1998;Stevanella et al, 2009;Prot et al, 2010;Rim et al, 2013); others assume a parabola representing a 2D cut-section of the PM shape, but where all chordae still insert on the tip (Park et al, 2019); and others still, assume them to have a spherical (Stevanella et al, 2011;Wang and Sun, 2013) or C-shape (Choi et al, 2016) (schematised in Figure 11) and create different insertion points for the chordae according to their classification. Recent studies based on ovine MV have looked into further characterising chordae tendineae geometry and topology (Khalighi et al, 2017), as well as evaluating how native chordal anatomic characteristics affect valvular performance (Khalighi et al, 2019).…”

“…The posterior leaflet has been mathematically characterised as a continuous shape around the annulus, with (Stevanella et al , 2009; 2011; Choi et al , 2016) or without (Kunzelman et al , 1993; Cochran and Kunzelman, 1998; Kunzelman et al , 2007; Domenichini and Pedrizzetti, 2015) scallop indentations. The main focus has been given to the mathematical definition of the complete leaflets’ free margin.…”

“…Computational modelling has been directed towards the study of MV function: while some studies have focused on normal physiological valve functioning (Votta et al , 2008; Wang and Sun, 2013; Domenichini and Pedrizzetti, 2015; Gao et al , 2017a), others have focused on diseased cases (Wenk et al , 2010; Rim et al , 2013; Choi et al , 2016) and surgical procedures (Ge et al , 2014; Rim et al , 2015; Rausch et al , 2017). The first geometrical models were based on idealised shapes of the MV, derived from literature data (Kunzelman et al , 1993; Salgo et al , 2002).…”

Mitral prolapse: An old mysterious entity – The incremental role of multimodality imaging in sports eligibility

“…The MV annulus is usually enlarged. [13] The so-called “Barlow disease” is an extreme form of degenerative mitral valve disease, characterized by excess connective tissue, redundant, thickened leaflets, marked annular dilatation, elongated, and thin (or thick/calcified) chordae. [10] On the other side, the fibroelastic deficiency is associated with thin, translucent leaflets, with collagen, elastin, and proteoglycans deficiency, moderate annular dilatation, and focal chordal elongation or rupture.…”