Left ventricular sub-valvar mitral aneurysms - Sub-aortic and sub-mitral left ventricular (LV) aneurysms have been collectively referred to as sub-valvar aneurysms, and were first described by Corvisart in 1812. Sub-valvar aneurysms have been described predominantly in the indigenous African populations of the world, although it has been reported in mixed races and Caucasians . A number of etiologies have been proposed for the develop- ment of the anatomical and pathophysiological processes associated with this condition, and the current consensus is that sub-valvar aneurysms are most likely due to a congenital weakness of the fibrous annulus of the valve.
Sub-aortic aneurysms usually occur in relation to the left coronary cusp of the aortic valve and the more common sub-mitral aneurysms in relation to the posterior annulus of the mitral valve. Pathophysiologically, sub-mitral aneurysms involve the fibrous mitral annulus and with enlargement displace the posterior mitral annulus and sub- valvar supporting apparatus apart, resulting in restriction of the posterior mitral leaflet and failure of leaflet coaptation with secondary mitral regurgitation. Clinical symptoms arise as a result of valvar regurgitation or occasionally from compression of cardiac structures. Interactive Cardiovascular and Thoracic Surgery 2 (2003) 547–551