DK2985_C000 1..28 - AlSharqia Echo Club

Intracavitary Contents 519endocarditis. Thus, TEE should be repeated within 7–10days if the clinical findings strongly suggest the diagnosisof endocarditis (30).Finding a mass on a valve is not necessarily specific ofactive infectious endocarditis. Non-infectious endocarditisalso occurs in Libman–Sacks (lupus) and marantic (paraneoplastic)endocarditis. Endocarditis secondary to granulomatousdisease and scleroderma has also been described.The non-infectious vegetations secondary to an inflammatoryprocess tend to be sessile without independent motionwhereas marantic vegetations may appear identical toinfectious vegetations (30).A. Echocardiographic Appearance ofa VegetationThe morphologic features of vegetations vary dependingon the nature of the offending organism, the state of theinvolved valve and the activity of the disease. Vegetationscan appear either as a discrete, sessile mass closely adherentto the valve, as pedunculated, friable clumps that prolapsefreely or as an elongated fibrous thickened strand(see Figs. 17.11 and 17.12). Fungal infections commonlygive rise to larger vegetations which are less likely tocause significant leaflet destruction than bacterial vegetations.Tricuspid valve vegetations are generally largerthan those located on the left heart.In acute endocarditis, the classic vegetation appears as acircumscribed, pedunculated echogenic mass arising fromthe leaflet tip with varying degrees of independent motion.Active vegetations typically appear soft and friable, asopposed to chronic healed vegetations which are moreecho-dense and fixed as they become fibrotic and calcified.Successful treatment of infectious endocarditis may notresult in complete disappearance and resolution of thevegetation.Vegetations can vary in size from a few millimeters orless to several centimeters and their appearance may dramaticallychange between studies because of growth, embolization,or valvular disruption. A complex appearance withcystic components may develop with certain vegetations,particularly those attached to foreign bodies (Fig. 23.33).As vegetations typically occur at sites of endothelialdamage due to impinging flow jets or on already structurallyabnormal valves, their appearance is influenced by theunderlying valvular disorder. In fact, the greater thedegree of valvular deformity before infection, the more difficultthe vegetation is to define. Extensive calcification maycause important shadowing and mask the presence of smallvegetation.The mitral valve is more frequently involved in infectiveendocarditis than any other valve. The vegetationsmay involve any of its leaflets and are most oftenlocated on the atrial surface of the valve. Infection ofboth mitral leaflets is not uncommon. Seeding of thechordae tendinae or the anterior mitral leaflet from aninfected AoV can also occur. Mitral valve vegetationsmust be differentiated from a variety of other disordersaffecting the valve including myxomatous degenerationwhich cause thickening of both leaflets and increasedechogenicity simulating endocarditis. When there isassociated leaflet prolapse or chordal rupture, the similaritymay be even more striking. Primary leaflet tumorsuch as fibroelastoma or myxoma may also at times beimpossible to differentiate from vegetations.The AoV is a common site of involvement in bacterialendocarditis. Combined infection of both aortic and mitralvalves is also frequently observed. Predisposing factors inAoV endocarditis include rheumatic deformity of thevalve leaflets, bicuspid AoV, and degeneration and calcificationof the aortic cusps frequently seen in the elderly.Aortic vegetation appears as a mass attached to the ventricularsurface of the cusps, in the outflow tract during diastoleand prolapsing forward through the annulus duringsystole. Aortic vegetations characteristically involve thebody or the free edges of the valve cusps. They are commonlyfocal and may involve one or two of the cusps.Endocarditis of the AoV can be complicated by the developmentof an abscess which appears initially as a periaorticasymmetric ill-defined thickening and swelling in(A)(B)VEGETATIONLALAARVLVFigure 23.33 Mid-esophageal 338 view of an intravenous drug user with endocarditis. Note the large complex vegetation on the atrialside of the mitral valve (LA, left atrium; LAA, left atrial appendage; LV, left ventricle; RV, right ventricle).