Anatomy, mechanics, and pathophysiology of the mitral annulus

Novel Mechanistic Insights Into Atrial Functional Mitral Regurgitation – 3-Dimensional Echocardiographic Study –

“…Mitral adaptation has been observed in patients with LV remodeling and MA dilatation in ischemic or dilated cardiomyopathy. 25 Although whether MA remodeling caused by AF-induced LA dilatation is also capable of such compensation has not been clarified thus far, 26 our results showed that the mitral leaflets demonstrated the capacity of adaptation by compensatory enlargement to some extent in response to mechanical stretch from MA dilatation caused by the LA remodeling. However, the leaflets were unable to cover the extremely enlarged MA completely, as seen in the decrease of the leaflet closure area to annulus area ratio in the patients with moderate-to-severe MR.…”

“…30 Other coexisting annular factors, such as the systolic circumferential contraction supporting effective leaflet coaptation and nonplanar geometry attenuating the leaflet stress, are also important for preventing regurgitation in a coordinated manner. 26 The present study also revealed that annulus flattening and contractile dysfunction progressed in parallel with severe enlargement of the LA and MA and they significantly exerted an influence on the worsening of atrial MR.…”

Peri-procedural imaging for transcatheter mitral valve replacement

“…The mitral annulus has a parabolic rather than planar geometry, with peaks toward the anterior and posterior edges (5). This unique shape is thought to lessen the stress exerted on the valve leaflets during systole.…”

“…It is important to note the close association of the coronary sinus with the posterior portion of the annulus, which is the basis for indirect annuloplasty procedures. The mitral annulus is a dynamic structure which undergoes a variety of deformations during the cardiac cycle including folding and contraction during systole, as well as translation in response to ventricular filling (5). The deformation of the annulus is a significant challenge for device stability in transcatheter mitral valve implantation (2).…”

Echocardiographic Assessment of Degenerative Mitral Stenosis: A Diagnostic Challenge of an Emerging Cardiac Disease

“…[17][18][19] Increased prevalence of MAC in patients with MV prolapse have been attributed to the annular trauma secondary to the excess tension caused by redundant hypermobile MV leaflets. 33 A genetic contribution to the risk of MAC has also been described. A genome-wide association study revealed an association between MAC and genetic polymorphisms near the pro-inflammatory gene IL1F9.…”