Significance of force transfer in mitral valve–left ventricular interaction: In vivo assessment

Abstract

This study is the first to assess the magnitude and time course of the longitudinal force transmitted through the papillary-chordal complex to the left ventricular wall during ejection. The study also demonstrates a significant force transfer to the closing force acting on the mitral valve leaflets that constitutes an essential component of valvular-ventricular interaction to enhance left ventricular systolic pump performance. The magnitude of the combined papillary muscle force component emphasizes the crucial role of preserving mitral valve-left ventricular continuity in mitral valve surgery.

Transapical mitral valve repair with neochordae implantation: FSI analysis of neochordae number and complexity of leaflet prolapse

“…Our FSI framework allowed for a direct and objective quantification of these forces in a virtual human beating heart for the first time. Moreover, the PM tension curves obtained for the baseline model quantitatively agree with PM force measurements performed in an vivo animal setting . A similar distribution trend was noticed for the neochordae tension curves but with a lower force magnitude.…”

“…Moreover, the PM tension curves obtained for the baseline model quantitatively agree with PM force measurements performed in an vivo animal setting. 51,52 A similar distribution trend was noticed for the neochordae tension curves but with a lower force magnitude. Generally, PM and neochordae forces increased rapidly during early systole and peaked between early and middle systole.…”

The Unsaddled Annulus

“…16 The underlying concept of a mechanically linked mitral mechanism extending from annulus to ventricular wall is supported by the evidence for force transmission within that system and provides the rationale for chordal preservation in MV replacement. 17–19 …”

The Impact of Fluid Inertia on In Vivo Estimation of Mitral Valve Leaflet Constitutive Properties and Mechanics

“…Therefore, the papillary muscle may not need to balance as much of the load during IVC due to initial fluid acceleration. As flow begins to decelerate, the muscle will need to take more load, which agrees with the subsequent high load experienced by the papillary muscle 2 . Comparatively there is little fluid inertia during IVR.…”

“…Later studies show that the force along the papillary muscle changes throughout the cardiac cycle. The combined force for both papillary muscles is 2.9 N at the beginning of systole and increases to 7.2 N at the end of systole 2 . To compare the contribution from inertia, we assume a stress contribution of 20 mmHg is applied uniformly along anterior and posterior leaflets, corresponding to a surface area of ~7 cm 2 .…”