Inter-scallop separations of the posterior leaflet of the mitral valve: an important cause of 'pathological' mitral regurgitation in rheumatic heart disease screening

The 2012 World Heart Federation (WHF) criteria for echocardiographic diagnosis of rheumatic heart disease (RHD) identify that the finding of 'pathological' mitral regurgitation (MR) in a screened individual increases the likelihood of detecting underlying RHD. Cases of isolated 'pathological MR' are thus identified as 'borderline RHD'. A large-scale echocardiographic screening program (Echo in Africa) in South Africa has identified that inter-scallop separations of the posterior mitral valve leaflet (PMVL) can give rise to 'pathological' MR. The authors propose that this entity in isolation should be identified and excluded from the WHF 'borderline RHD' category. In this case report, we present two examples of 'pathological' MR related to inter-scallop separation from the Echo in Africa image database. We further provide screening tips for the accurate identification of this entity.