Abstract All patients who are candidates for transcatheter closure of an ostium secundum atrial septal defect (ASD) should undergo a detailed echocardiographic assessment using 2D transesophageal echocardiography (TEE) prior to the procedure. It is essential for a comprehensive analysis of interatrial septal anatomy and for determining defect eligibility for the procedure. The type, number, size, location and morphology of the ASD, as well as the quality of the surrounding septal tissue and its relationship with adjacent cardiac structures, should be […]