There is no trustworthy estimate of the incidence of congenital heart disease as a whole, still less of tricuspid atresia. Doubtless many infants have died with tricuspid atresia, on whom no post-mortem examination was made, with merely a diagnosis of congenital heart disease or even unrelated diagnoses, since many of them succumb to infections such as pneumonia, meningitis, septicaemia. The fi...