Andersons pediatric cardiology 1460

Echocardiography and Rheumatic Heart Disease Echocardiography is a noninvasive portable diagnostic tool that has become affordable even in resource-poor settings In most of the world, echocardiographic diagnosis has replaced the clinical diagnosis of RHD.21 Echocardiography is essential to ■ Diagnose acute rheumatic carditis in an individual with suspected ARF ■ Confirm the diagnosis of RHD in individuals without a clinical history of ARF ■ Grade the severity of valvar dysfunction ■ Assess serial LV size and function ■ Guide the timing and nature of surgical intervention ■ Determine the duration of secondary prophylaxis ■ Screen for latent and subclinical RHD that would otherwise be missed on clinical examination Mitral Valve Disease Chronic MV disease is the most common manifestation of RHD The natural history of rheumatic MV disease has been described as a pendulum swinging from regurgitation to complete resolution without evidence of heart disease in some cases but progression to mixed MR/MS or pure valvar stenosis in others.18 In children, isolated pure MR is the most common form of chronic RHD Early in the disease process the leaflets remain relatively thin, chordae elongate, and the annulus dilates, leading to valvar regurgitation With time, scarring and fibrosis of the leaflet apparatus result in rigidity and restricted movement of the leaflets The appearance of the anterior MV leaflet is often described as a “dog leg” or “hockey stick” deformity (Figs 55.4 and 55.5) With time the leaflets thicken, retract, and calcify There is also commissural fusion as well as chordal shortening, thickening, and fusion leading to MS (Figs 55.6 and 55.7) Progressive calcification of the MV apparatus may develop This process often takes many decades25,35; however, in some regions of the world where ARF remains hyperendemic, progression to severe MS can be very rapid and affect children as young as 5 to 10 years of age This is often referred to as juvenile or malignant MS.19