Which echo view is considered the standard for contrast studies of an atrial septal defect (ASD)?

The apical 4-chamber view is considered the standard for contrast studies of an atrial septal defect (ASD) for several reasons. This view provides a comprehensive perspective of the heart's anatomy, allowing for the visualization of both atria and their corresponding septal structures.

In the apical 4-chamber view, the left and right atria are well delineated, enabling the assessment of any shunting that occurs due to the ASD. The use of contrast enhances the ability to identify and evaluate the size and location of the defect, as well as the direction of blood flow between the atria. Moreover, this view allows for a clear evaluation of associated structures, such as the atrioventricular valves and right ventricle, which are important in assessing the hemodynamic effects of the defect.

While other views like the subcostal 4-chamber view can also provide valuable information regarding ASDs, especially in certain patient populations such as those with suboptimal acoustic windows, the apical 4-chamber view is preferred in standard practice due to its clarity and comprehensive visualization, making it crucial for effective assessment and diagnosis of atrial septal defects.