Tricuspid atresia definition Tricuspid atresia is a congenital absence of atrioventricular valve connection between the right atrium and right ventricle, replaced by septal tissue, usually with hypoplastic right ventricle and normal or enlarged left ventricle, often combined with an atrial septal defect, a narrow or normal pulmonary valve, and a normal left mitral valve, forming a functionally single ventricle. The incidence of this disease is rare and accounts for 1% to 3% of all precardiac disease. Clinical manifestations Patients are born with varying degrees of cyanosis, shortness of breath and dyspnea, malnutrition, pestle-like fingers (toes) may be found around two years of age, cyanosis may worsen if there is pulmonary stenosis or subvalvular stenosis, sometimes the symptoms may be mild. On physical examination, the patient shows cyanosis, pestle-like fingers (toes), and systolic murmurs can be heard at the left border of the sternum.