How this thing works...Etiology/pathophysiology of MVP.

The mitral valve is made up of three distinct layers: Atrial side, the spongiosa, and the fibrosa of the ventricular side.



(Delling and Vasan, 2014)





Prolapse of the intermediate posterior mitral valve scallop (P2) shown in a long-axis view of (A) a 2-dimensional (2D) transthoracic echocardiogram, (B) a 2D transesophageal echocardiogram (TEE) with (C) associated severe, eccentric, anteriorly directed mitral regurgitation, and (D) a 3-dimensional TEE surgical view. AO indicates aorta; LA, left atrium; LV, left ventricle; and RV, right ventricle.
(Delling and Vasan, 2014)


The reason for mitral valve prolapse arises from either of two degenerative processes of main histological phenotypes: diffuse myxomatous disease (Barlow's disease) or fibroelastic deficiency.

Barlow's disease is characterized by thickened and diffusely redundant myxomatous leaflet tissue with disrupted collagen and elastic layers, leading to prolapse.

Fibroelastic deficiency is characterized by decreased connective tissue deficient in collagen, elastin, and proteglycans. This may lead to chordal rupture and flail leaflets, thus causing prolapse to occur.
 (Delling and Vasan, 2014)


References

Delling, F. N., & Vasan, R. S. (2014). Epidemiology and Pathophysiology of Mitral Valve Prolapse: New Insights Into Disease Progression, Genetics, and Molecular Basis. Circulation, 129(21), 2158-2170.