Characterization of Degenerative Mitral Valve Disease: Differences between Fibroelastic Deficiency and Barlow’s Disease

Figures

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  Figure 1. Morphological features of normal and degenerative mitral valve disease. Normal (A–C) and degenerative mitral valves (D–I) are stained for elastin (A,D,G; Weigert’s Resorcin Fuchsin), collagen (B,E,H; Masson’s Trichrome) and glycoaminoglycans (GAGs; C,F,I; Alcian blue). Degenerative mitral valves (D–I) are characterized by an abnormal organization of the extracellular matrix with disrupted elastin (D,G), diminished and loose collagen in the fibrosa layer (E) and expansion of the spongiosa layer (F,I). In addition, superimposed tissue (SIT) can be present at the atrial and ventricular sides of the original leaflet, contributing to increased thickness of the leaflet (G–I). Scalebar: 500 mm.

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  Figure 2. Transthoracic echocardiography: Differences between fibroelastic deficiency and Barlow’s disease. Transthoracic echocardiography images (parasternal long-axis view (A–E,G–K) and four-chamber view (F,L)) presenting the differences between FED and Barlow’s disease. Panels A and G displays the difference in prolapsing segment, including the prolapse height. Patients with FED have a single segment prolapse compared to the bileaflet prolapse of Barlow’s disease patients. As displayed in panels B and H, patients with Barlow’s disease have thick leaflets compared to the thin leaflets in FED. Panels D and J demonstrate that the mitral valve annulus diameter is larger in Barlow’s disease compared to FED, where the annulus is within the normal range. Patients with Barlow’s disease often have MAD, as presented in panel K with the red arrow, whereas this is rare in patients with FED (panel E showed no signs of MAD). Panels C, F, I and L show = mitral regurgitation in both patients, with patients with Barlow’s disease more often having multiple jets compared to the single jet in FED patients. FED = fibroelastic deficiency, LA = left atrium, LV = left ventricle and MAD = mitral annular…

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  Figure 3. Two-dimensional (color) and three-dimensional transesophageal echocardiographic differences between fibroelastic deficiency and Barlow’s disease. Transesophageal echocardiography including 3D images for a patient with fibroelastic deficiency (A–C) and a patient with Barlow’s disease (D–F). Panels A and D display the 3D transesophageal images, showing the detailed anatomy of the valve with a single prolapsing segment in panel A and a multiscallop, bileaflet prolapse in panel D (red arrows). Panels B and E show the 2D view with the mitral valve annulus plane (red line); the patient with fibroelastic deficiency presented a single segment prolapse and the patient with Barlow’s disease a bileaflet prolapse. Panels C and F show the color-Doppler images with mitral regurgitation. LA = left atrium and LV = left ventricle.

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  Figure 4. CMR examples of patients with Barlow’s disease. CMR images of two patients with Barlow’s disease. Panels (A–C) represent Patient 1 with Barlow’s disease, showing mitral annular disjunction (blue arrow) and a clear bileaflet prolapse. Panels (D–F) represent Patient 2 with late gadolinium enhancement at the level of the papillary muscle (orange arrow). CMR = cardiac magnetic resonance imaging, LA = left atrium and LV = left ventricle.