Final answer:
The preferred view to examine a secundum atrial septal defect is the Subcostal four chamber view, providing clear visibility of the interatrial septum for accurate diagnosis.
Step-by-step explanation:
The view of choice when examining a patient with a secundum atrial septal defect is Subcostal four chamber. In the context of echocardiography, this view is particularly helpful as it allows clear visualization of the atrial septum, where a secundum atrial septal defect occurs. The subcostal four-chamber view can bypass any anterior structures like the chest wall or ribs, which may obstruct the view of the interatrial septum from other echocardiographic planes. Additionally, it is an excellent view to examine patients who may have difficulty with standard echocardiographic views due to body habitus, lung disease, or chest wall deformities.
Figure 19.10 illustrates various congenital heart defects, including defects in the atrial septum. When the septa of the heart do not form correctly, it can lead to conditions such as a secundum atrial septal defect, which is characterized by an abnormal opening in the interatrial septum, allowing blood to flow between the two atria. For accurate assessment and diagnosis, the subcostal four-chamber view is recommended for imaging this area of the heart.