Abstract
In a 3 year-old girl with acyanotic tetralogy of Fallot, preoperative echocardiography revealed a thick fibrous tissue hanging on the right side of large ventricular septal defect. According to the definition of Kirklin, we diagnosed it as “flap valve ventricular septal defect.” And this diagnosis was supported by the findings of electrocardiogram and cardiac catheterization. At the operation, it was confirmed that the flap was only attached to the posterior margin of ventricular septal defect, and that it hardly played any part in tricuspid valve function. To our knowledge, this is the first case of “tetralogy of Fallot with flap valve ventricular septal defect” reported in Japan.