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Electrocardiogram
Published in Kayvan Najarian, Robert Splinter, Biomedical Signal and Image Processing, 2016
Kayvan Najarian, Robert Splinter
As can be seen in Figure 9.1, the heart has four chambers: two atria and two ventricles. The atria work in unison and so do the ventricles. The atrium is separated from the venous system by a valve so that flow is only possible in one direction. The superior vena cava and the inferior vena cava lead into the right atrium in combination with the coronary sinus, while the pulmonary veins supply the left atrium. When the atrium contracts, it pumps the retained blood into the ventricle that is separated by a valve as well. The valve only allows flow from the atrium to the ventricle and not in the opposite direction. This valve is called the atrioventricular valve. The atrioventricular valve between the right atrium and the right ventricle is also called the tricuspid valve because of the three-leaf structure. The left atrium and left ventricle have the bicuspid valve, or mitral valve, that separates the two chambers.
Medical Applications of Ultrasonic Energy
Published in Dale Ensminger, Leonard J. Bond, Ultrasonics, 2011
Dale Ensminger, Leonard J. Bond
Echocardiography is also useful in evaluating the degree of stenosis (narrowing of the opening) in mitral-valve disease [109]. The transducer is aimed at the anterior mitral leaflet, and the echo signal is recorded on a strip chart so that an upward movement of the recorder pen corresponds to the movement toward the ultrasonic transducer and a downstroke represents movement away from the transducer. Thus, the slope of the tracing is an indication of the velocity of motion. The degree of stenosis affects the rate at which the blood flows through the opening. The speed of the diastolic downstroke during the period of ventricular filling is affected, slowing down with increased stenosis. This slowing down is readily discernible by the corresponding slope of the ultrasound cardiogram strip-chart recording. Rigidity or calcification of the valve is indicated by a decrease in the total amplitude of the movement of the anterior mitral leaflet between the closed position, during ventricular systole and the position of maximum opening in early diastole.
Coanda Effect in a Human Body
Published in Noor A. Ahmed, Coanda Effect, 2019
To understand mitral valve malfunctioning, the anatomy of a normal heart and the location of the mitral valve [47] is shown in Figure 5.16. The mitral valve is an organ that allows flow between two chambers of the heart, from the left atrium to the left ventricle. When part of the mitral valve loosely slips backwards into the left atrium, the condition is called mitral valve prolapse. The most common cause of mitral valve prolapse is the chordal elongation of the valve leaflets which, when it is detected, may also be an indication of severe mitral regurgitation.
New synthetic mitral valve model for human prolapsed mitral valve reconstructive surgery for training
Published in Journal of Medical Engineering & Technology, 2020
Dylan Goode, Sevda Mohammadi, Ray Taheri, Hadi Mohammadi
The human mitral valve is located between the left atrium and ventricle chambers. It consists of two leaflets known as the anterior or posterior leaflets, the left atrial wall, the annulus, the chordae tendineae, the papillary muscles and the left ventricular septum (as shown in Figure 1). The leaflets are known to be flexible, glowing, thin, and soft. The anterior leaflet is attached to the aortic root and is positioned respectively posterior to the aortic root. This leaflet is known to be large compared to the posterior leaflet and holds a crescent-shape geometry with two identifiable zones. The two identifiable zones on this leaflet are represented as clear and rough zones which are divided by a prominent ridge on the atrial face of the leaflet. The prominent ridge is positioned roughly 10 mm from the free edge of the anterior leaflet. The posterior leaflet is just behind the 2 commissural zones and has a broader connection to the annulus compared to the anterior leaflet. The whole leaflet is in fact 3 scallops formed by 2 clefts (as shown in Figure 1) with the middle scallop being the larger of the three. The other two scallops are known as the anterolateral and posteromedial commissural scallops. The 3 identifiable areas on the posterior leaflets are known as rough, clear, and basal [15,16].
Reduced basis model order reduction for Navier–Stokes equations in domains with walls of varying curvature
Published in International Journal of Computational Fluid Dynamics, 2020
Martin W. Hess, Annalisa Quaini, Gianluigi Rozza
We consider the flow of an incompressible fluid through a planar channel with a narrowing, where the walls creating the narrowing have variable curvature. An application that motivated the present study is the flow of blood through a regurgitant mitral valve. Mitral regurgitation (MR) is a valvular disease characterised by abnormal leaking of blood through the mitral valve from the left ventricle into the left atrium of the heart (see Figure 1). In certain cases, the regurgitant jet ‘hugs’ the wall of the heart's atrium as shown in Figure 1 (right). These wall-hugging, non-symmetric regurgitant jets have been observed at low Reynolds numbers (Albers et al. 2004; Vermeulen et al. 2009) and are said to undergo the Coanda effect (Wille and Fernholz 1965). Such jets represent one of the biggest challenges in echocardiographic assessment of MR (Ginghina 2007). In Quaini, Glowinski, and Canic (2016), Pitton, Quaini, and Rozza (2017), Pitton and Rozza (2017), Wang et al. (2017), Hess et al. (2018) and Hess, Quaini, and Rozza (2018), we made a connection between the cardiovascular and bioengineering literature reporting on the Coanda effect in MR and the fluid dynamics literature with the goal of identifying and understanding the main features of the corresponding flow conditions.
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 mitral valve is the cardiac valve separating the left atrium from the left ventricle. It is composed of four elements: the anterior and posterior leaflets; the annulus which serves as insertion site in the heart muscle for the leaflets; the chordae tendineae which are attached to pillars in the ventricular wall and ensure that the very flexible leaflets remain within the ventricle; the papillary muscles which are located at the tip of the chordae tendineae and actively modify the tension acting on the leaflets. In the physiological case, the valve is open during diastole letting blood flow into the ventricle, and close during systole: the leaflets then create a hermetic seal between the two chambers preventing blood from regurgitating into the left atrium when ejected into the aorta. Mitral insufficiency is a valvular heart disease caused by a leaky mitral valve. It is the most frequent valvular pathology in Western countries after aortic narrowing upon calcification (Singh et al. 1999).