结论上腔静脉内径、右房室口直径、第一房间隔高度和宽度随胎龄的增长而增加。
Conclusion As the growth of age , the internal diameter of superior vena cava , the diameter of right atrioventricular orifice and the height and breadth of the first septum of the right atrium is increasing .
第一房间隔