Aberrant mitral valve chordae and in particular on the AMVL are an extremely rare finding with only a handful of cases reported in the literature [1, 2, 4].
In our case these true chordal structures were absent in the A2 segment of the AMVL. This on its own would have resulted already in a prolapse of the A2 segment.
A possible explanation for the delay in symptoms in our case could be that with growth and further dilatation of the left atrium, the aberrant chord pulled the AMVL more towards the atrium, resulting in an increase of leaflet prolaps and increased reversal regirgutant flow.
In our case the missing chordae at the A2 segment resulted in a prolapse of the AMVL. As per usual, chronic mitral regurgitation had resulted in left ventricular dilatation and enlargement of the posterior muscular portion of the mitral valve ring.