Excessive papillary muscle traction and dilated mitral annulus in mitral valve prolapse without mitral regurgitation.

This study demonstrated excessive papillary muscle displacement during peak systole but normal mitral annulus function during the cardiac cycle in patients with mitral valve prolapse and no mitral regurgitation. The excessive papillary muscle displacement may play an important role in the pathogenesis of the superior displacement of mitral leaflets in patients with mitral valve prolapse.