Mitral annular disjunction: Is MAD ‘normal'

This editorial refers to ‘Prevalence and extent of mitral annular disjunction in structurally normal hearts: comprehensive three-dimensional analysis using cardiac computed tomography’ H. Toh et al. pp. 614--22. In 1986, Hutchins et al.1 examined 900 post-mortem hearts, where 25 had typical features of mitral valve prolapse (MVP). The mitral annulus was described. Twenty-three of these MVP hearts showed evidence of separation of atrial wall-mitral valve leaflet junction with the ventricular myocardium. Only 42 of 875 non-MVP hearts showed a similar finding. This apparent anomaly was coined mitral annulus disjunction (MAD). Since the latter group were considerably younger, the authors postulated that over time the hypermobility of the mitral annulus may be linked with the progression of myxomatous valve disease. It is worth noting only one block was taken for histological examination from the obtuse margin of the annulus from each normal heart. A number of studies, both post-mortem...