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Cardiovascular System:
Published in Michel R. Labrosse, Cardiovascular Mechanics, 2018
To prevent the backflow of blood, the heart contains two sets of one-way valves (Figure 1.3)—the atrioventricular valves (A-V) and the aortic/pulmonary valves—which are supported by a connective tissue base called the fibrous skeleton. The valves may be open or closed, depending on the pressure difference on either side of the valve. The A-V valves are situated between the atria and the ventricles. The right A-V valve has three cusps (or flaps) and is often referred to as the tricuspid valve. The left A-V valve has two cusps and is often referred to as the mitral valve or the bicuspid valve. When atrial pressure is higher than ventricular pressure during diastole (the relaxation phase), these valves are pushed open to allow for ventricular filling. When the ventricles begin to contract in systole, the increasing pressure in the ventricles pushes the valves closed, thus ensuring only forward blood flow. To prevent the A-V valves from everting, the valves are anchored by small tendon-like fibers called the chordae tendinae, which attach to the valve flaps and originate in the papillary muscle of the ventricles. As the ventricles contract, the papillary muscle also contracts, adding tension to the chordae tendinae and ensuring that the valve remains in a proper closed position. As the ventricles return to relaxation and the ventricular pressure drops below the atrial pressure, the valves open once again.
A new device to treat mitral valve regurgitation: a proof of concept in bench test study
Published in Journal of Medical Engineering & Technology, 2021
Giovanni Alfonso Chiariello, Saimir Kuci, Guglielmo Saitto, Massimo Massetti, Ottavio Alfieri, Jacob Zeitani
Tests aiming to evaluate the effectiveness of the valve repair using the proposed device showed in all five swine heart models with mitral valve artificially made incompetent by cutting the primary chordae from the posterior papillary muscle to the posterior leaflet, P2 scallop, at the three different speeds considered (1000, 1500 and 1750 rpm) LV pressure normalised after having repaired the valve by mean of two pair of artificial Gore-Tex chordae anchored to the device and sutured to the prolapsed free margin leaflet (Table 3). Moreover, no significant fluid loss difference was observed between normal hearts with the device implanted and hearts with a device implanted and repaired valve (Table 4).
Use of a parametric finite element model of the mitral valve to assess healthy and pathological valve behaviors
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2019
T. Alleau, L. Lanquetin, A.-V. Salsac
The annulus of the mitral valve is defined using a planar D-shape, similarly to the Carpentier-Edwards Physio annuloplasty ring (Edwards Lifesciences). The papillary muscles tips are placed at fixed positions obtained from medical data (Sakai et al. 1999). The chordae tendineae are created as uniformly distributed chords going from the edges of the leaflets to the papillary muscle tips.