Congenitally Unguarded Tricuspid Orifice with Coexistent Pulmonary Atresia.

AGENESIS of the tricu.spid valve may occur in two forms: (1) tricuspid atresia and (2) "tunguarded tricuspid orifice." In the latter, althouigh the normal orifice between the right atritum and right ventricle exists, there is no tricuspid valvtular tissue. The purpose of this report is to describe the clinical, radiologic, and pathologic findings of suich a case in which ptulmonary atresia coexisted. The entity of congenitally unguiarded tricuispid orifice has some similarity to the case reported by Klein. As far as we are aware, no other similar case is in the literature.