Abstract
Congenital heart disease is a common disorder. Ventricular septal defect and atrial septal defect are the most common pathology, comprising approximately 40% of cases of congenital heart disease. As in most types of congenital heart disease, echocardiography has become the keystone for precise diagnosis and determination of the direction of clinical care and approach to therapeutic intervention in these disorders. Thus, although the presence of ventricular septal defect or atrial septal defect is often easily detected, ideal echocardiographic evaluation and interpretation require that one has a detailed understanding of septal anatomy, the relationships of defects to other cardiovascular structures, and the impact of these defects on hemodynamics.