HYPOPLASTIC POSTERIOR MITRAL LEAFLET ASSOCIATED WITH OSTIUM SECUNDUM ATRIAL SEPTAL DEFECT

Hypoplastic posterior mitral leaflet is a very rarely seen congenital mitral valve abnormality in adults. Most commonly associated cardiac lesions include; bicuspid aortic valve (23%) and ostium secundum atrial septal defect (12%). We report about a symptomatic 56-year-old patient with ostium secundum atrial septal defect, who was incidentally diagnosed with hypoplastic posterior mitral leaflet and moderate mitral regurgitation. The anterior mitral leaflet was myxomatous with large segment prolapse noted. Comprehensive echocardiographic imaging including 3-dimensional assessment is a key to diagnose this condition which mandates a surgical mitral valve repair/replacement in most cases with significant mitral regurgitation.