Echocardiography is the imaging modality of choice to diagnose different types of atrial
septal defect and to determine which defects are suitable for catheter occlusion. In
addition to assessment of defect size and rims, transoesophageal echocardiography may
be used to guide the procedure itself including device placement, procedural complications
and post-procedural checks. This review covers a practical approach to this subject and is
accompanied by online videos illustrating the technique