| Popis: |
As was emphasised several decades ago by Perloff and Roberts, the mitral valve is best considered in terms of a valvar complex. It is comprised of the left atrioventricular junction, the valvar leaflets, the tendinous cords supporting the leaflets, and the papillary muscles, with the muscles themselves supported by the ventricular myocardium. Although not followed for centuries, it is a basic rule of anatomy that all these entities should be described in the setting of the heart within the body. This means that the leaflets are best described as being aortic and mural, whilst the papillary muscles are positioned infero-septally and supero-laterally within the cavity of the left ventricle. In our chapter, we first discuss why the valve is considered to be “mitral,” emphasising its similarity when viewed from the ventricle to the episcopal mitre. We emphasise that the valve belongs to the left ventricle, but has a different morphology when guarding the left side of a common atrioventricular junction. We discuss the important surgical relationships of the valve when describing the anatomy of the left atrioventricular junction. We also emphasise the significance of appreciating the relationship of the valve to the left ventricle of the presence of the infero-septal recess of the aortic root. We then discuss the structure of the leaflets and the naming of their constituent parts, as we for subsequently for the tendinous cords. We pay particular emphasis for the presence of so-called “disjunction” of the hinge of the mural leaflet, pointing out that this feature is a ubiquitous finding in the normal heart. |
