DK2985_C000 1..28 - AlSharqia Echo Club

330 Transesophageal EchocardiographyFigure 15.1 View of heart valves in systole and diastole with both atria removed. Note that the aortic valve in diastole resembles thelogo of the Mercedes Benz company while in systole it has a triangular opening. The noncoronary cusp is positioned posteriorly, oppositeto the atrial septum. The relationship of the right and left fibrous trigone to the aortic valve is indicated. Also note the relationship ofthe aortic valve to the membranous septum and the division of this structure into an interventricular and an atrioventricular componentby the tricuspid valve leaflet insertion. [Anatomic drawings with permission of Netter and Yonkman (1).]ventricular outflow tract (LVOT). Within the aorticroot, the coronary ostiae are located in the sinuses ofValsalva (Fig. 15.3). The right and left coronary cuspsare associated with the origin of the coronary arterywhich bears the same name. The noncoronary cusplocated posteriorly, is not associated with a coronaryostium and is in close proximity to the atrial septum(Fig. 15.1). The height of the aortic cusps is slightlyless than half the length of its free margin. The freeedge of each cusp is concave and there is a large contactzone between the cusps which creates a visible zoneof redundancy, the lunula, above the closure line(Fig. 15.4). On the ventricular surface of each aortic cuspthe nodule of Arantius is located in the center of the freeedge at the point of coaptation (Fig. 15.4). Lambl’s excrescencesare thin mobile filamentous strands that are commonlyobserved on the aortic valve in elderly patients.They are variable in number and usually appear near theclosure line. Lambl’s excrescences can measure 1 mm inthickness and up to 1 cm in length. They are thought tooriginate from small endothelial tears on the surface ofthe aortic valve. They contain a fibroelastic core and arecovered by a thin layer of endothelial cells. These strandsare not pathological, their incidence increases with ageand they should not be mistaken for AoV pathology orendocarditis (see Chapter 23, Fig. 23.16).