The overall prevalence of<unk>  is estimated at 10%. Interestingly, the two annuli of the mitral valve are not affected equally, with the posterior annulus demonstrating<unk>  more frequently than the anterior annulus. When<unk>  does result in mitral stenosis (MS), it does not produce the classical fusion of the commissures seen in rheumatic heart disease, which allows these two common underlying causes of MS to be differentiated.
Mitral annular calcification
Bicuspid aortic valve
Quadricuspid aortic valve
Supravalvular aortic stenosis
Flutter valve
Mitral annular disjunction
Accessory auricle
Overriding aorta