Multiscale structure and function of the aortic valve apparatus

Figures

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  FIGURE 1.. Proposed anatomy and nomenclature of the aortic valve apparatus (AVA), which includes all the tissue from the beginning of the left ventricle (LV) outflow tract (LVOT) in the LV to the sino-tubular junction (STJ) at the beginning of the ascending aorta. This includes the LVOT that is embedded in the LV myocardium, the 3 interleaflet triangles, the 3 sinuses of Valsalva, the left and right coronary ostia, the 3 leaflets, the 3 commissure points, and the STJ.

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  FIGURE 2.. Leaflet definitions displayed through a cross-sectional cut through the middle of the aortic valve apparatus (AVA) during diastole.

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  FIGURE 3.. Nodule of Arantius (enclosed by the black dotted line) on the ventricular surface of the leaflet (enclosed by the black line). The leaflet height is smaller than the sinus height. The coronary ostium’s (enclosed by the yellow dotted line) position is superior to the leaflet and inferior to the sino-tubular junction (STJ). Adapted from Ref. 9, with permission from European Journal of Echocardiography.

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  FIGURE 4.. Three-dimensional (3-D) fluid-structure interaction (FSI) simulation results for aortic valve deformations during opening and closing for leaflet thickness 0.2 mm (A), 0.3 mm (B), 0.5 mm (C), 0.6 mm (D), and 0.8 mm (E). Adapted from Ref. 12, with permission from Journal of Fluid Mechanics.

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  FIGURE 5.. Schematic representation of the superimposed aortic valve orifices during systole. Adapted from Ref. 32, with permission per Open Access terms.

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  FIGURE 6.. Two (2-D)- and three (3-D)-dimensional velocity profiles for healthy aortic valve (AV) (A) and stenotic AV (B). Adapted from Ref. 38, with permission from Journal of Biomechanical Engineering.

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  FIGURE 7.. Collagen fibers of the aortic leaflet. The top of the leaflet sample is the free edge, and the semicircular bottom edge is the line of attachment to the walls of the sinus. Adapted from Ref. 46, with permission from the American Physiological Society.

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  FIGURE 8.. The microstructure of a healthy aorta, composed of the intima (I), the media (M), and the adventitia (A). The relative thicknesses of the three layers are only indicative and vary with axial location. Adapted from Ref. 66, with permission from Journal of The Royal Society Interface.

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  FIGURE 9.. Confocal images of the nerves in the sino-tubular junction (STJ) (A), sinus (B), annulus (C), and control (D). Red is neurofilament protein (NF), green is choline acetyl transferase (ChAT), and yellow is colocalization of both NF and ChAT. Adapted from Ref. 88, with permission from Journal of Molecular and Cellular Cardiology.

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  FIGURE 10.. Electrical field stimulation frequency response curves for sino-tubular junction (STJ) tissue (A), sinus tissue (B), and leaflet tissue (C). Adapted from Ref. 88, with permission from Journal of Molecular and Cellular Cardiology.

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  FIGURE 11.. The relationship between size and shape of the wings of a swift and the speed of lift during flight. A–C: adjusting sweep angle (A) alters wing area (B) and aspect ratio (C). D: lift and drag coefficients for different sweep angles at a glide speed of 10 m/s, where α = angle of attack. E and F: effect of sweep angle (E) and glide speed (F) on lift and drag. Adapted from Ref. 96, with permission from Nature.

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  FIGURE 12.. A: the hinge mechanism located between the left and right fibrous trigones (location indicated by the two small arrows). Adapted from Ref. 92, with permission from Annals of Thoracic Surgery. B: stained section through the noncoronary sinus and leaflet showing the attachment of the hinge to the right fibrous trigone. The blue stain shows the glycosaminoglycans (GAGs), whereas the red stain shows the collagen content. Adapted from Ref. 103, with permission per Open Access terms.