Supramitral ring: an unusual cause of congenital mitral stenosis. Case series and review.

Supramitral ring, also known as membranous supravalvular mitral stenosis is a rare cause of congenital mitral stenosis, with less than 100 cases appearing in the literature since its first description in 1902. We present a small series encountered at the university medical center during the last five years. The natural history of the condition is reviewed along with diagnostic tools, aspects of surgical repair, and anesthetic technique that facilitates early extubation and ICU discharge.