Congenitally unguarded tricuspid valve orifice with right ventricular apical isolation in an adult

Congenitally unguarded tricuspid valve (TV) orifice, a variant of TV dysplasia, is a rare malformation with protean manifestations. This report describes a symptomatic adult male with gross right heart failure and atrial fibrillation, who was found to have an unguarded TV orifice with isolation of the trabecular apical cavity of the right ventricle (RV) and muscular ridges separating outflow tract (forme-fruste of the double-chambered RV). The right ventricular outflow tract remained patent.