Analysis of 12 cases of intervention of patent foramen ovale closureZHANG Shen-wei1,GUO Jing1,GUO Wen-yi2,CAO Feng2,YU Li1,YUAN Yi-qiang1(1.Department of Cardiology,Seventh People’s Hospital,Zhengzhou 450017,Henan,China;2.Department ofCardiology,Xijing H