Letter: congenital mitral regurgitation due to 'posterior reinsertion' of chordae tendineae.

A rare type of congenital mitral regurgitation is presented for the first time as an isolated cardiac anomaly. The malformation consists of a particular arrangement of the chordae tendineae of the posterior leaflet: the chordae, leaving the free margin or the undersurface, insert into the latter once again. A definition of the anomaly and a classification of all the chordal anomaliesfound in congenital mitral regurgitation are proposed. The clinical picture is briefly reported.