DK2985_C000 1..28 - AlSharqia Echo Club

Native Aortic Valve 331Figure 15.2 (A, B) Mid-esophageal short-axis view of the aortic valve. Anatomical aspect of the aortic valve in diastole (C) and insystole (D) (LA, left atrium; LCC, left coronary cusp; NCC, noncoronary cusp; RA, right atrium; RCC, right coronary cusp; RV, rightventricle) (1, RCC; 2, LCC; 3, NCC; 4, ventricular septum; 5, aortic commissure; 6, aorta; 7, lunula; 8, nodules of Arantius). (Photos Cand D courtesy of Dr. Nicolas Dürrleman.)The relationship of the AoV to structures within ornear the base of the heart is important in understandingpathological echocardiographic findings. The AoV ispart of the fibroskeleton at the base of the heart. The leftand the noncoronary cusp are in fibrous continuity withthe anterior leaflet of the mitral valve (MV) (Fig. 15.5).This fibrous continuity is the subaortic curtain, ormitral–aortic intervalvular fibrosa. It is located betweenthe two fibrous trigones which are the strongest componentof the cardiac fibroskeleton. The left trigone is in closeproximity to the posterior aspect of the left coronarycusp (Fig. 15.3) while the right fibrous trigone is oppositethe noncoronary cusp (Fig. 15.1). The conduction systemis located near the posterior noncoronary cusp and maybe injured during AoV surgery or involved by endocarditis.The membranous septum immediately below the AoVis divided by the attachment of the tricuspid valve(TV) into an interventricular and an atrioventricular component(Fig. 15.1). The AoV is also in close proximity tothe other heart valves and to both the left and rightatrium (RA).B. Congenital Anomalies of the Aortic ValveCongenital anomalies of the AoV include bicuspid, unicuspid,and quadricuspid valves. Pentacuspid AoVs havealso been described (2). The most common congenitalanomaly of the AoV is a bicuspid AoV with an occurrenceof 1–2% in the general population. A bicuspid AoV mayhave two equal cusps with a commissural opening thatmay be oriented in either a vertical or a horizontal position(Fig. 15.6). A bicuspid valve may also have one small cuspand a larger one with a raphe resulting from the failure ofseparation of two cusps. Most commonly, the raphe will beobserved between the right and the left coronary cusps(Fig. 15.7). This rudimentary raphe predisposes thelarger leaflet to restricted leaflet motion and premature calcification.A bicuspid valve with a raphe between twocusps will have an eccentric opening in systole (nearerone of the aortic walls) while in diastole the valve mayappear to have normal tricuspid morphology (Fig. 15.7).Therefore, echocardiographic evaluation of the AoVshould be done in systole and in diastole. A bicuspid