Accessory mitral valve leaflet causing aortic regurgitation and left ventricular outflow tract obstruction. Case...

Arrhythmias, aortic regurgitation, and symptoms of severe intermittent ventricular outflow obstruction developed in a 14 year old boy with a heart murmur who had been followed from infancy. These were caused by an accessory mitral leaflet, which was successfully removed at open heart operation. A review of 21 previously reported cases found a high incidence of associated cardiac malformations, appreciable subaortic obstruction in most patients, and a consistent attachment of the accessory tissue to the ventricular aspect of the anterior mitral leaflet. The characteristic echocardiographic appearance of a mobile mass arising from the area of aortic-mitral continuity is sufficient for the diagnosis of accessory mitral leaflet and echocardiographic examination will facilitate the surgical management of this condition.