Tricuspid atresia

In tricuspid atresia, the tricuspid valve is missing. Blood can't flow from the right upper heart chamber (right atrium) to the right lower heart chamber (right ventricle). This condition often includes an underdeveloped right ventricle as well as hole in the heart between the upper chambers (atrial septal defect). Sometimes, there's also a hole between the lower heart chambers (ventricular septal defect).