Which echocardiographic view is best for diagnosing a sinus venosus ASD?

The modified subcostal four chamber view is regarded as the best echocardiographic view for diagnosing a sinus venosus atrial septal defect (ASD) due to its specific ability to visualize the anatomy around the interatrial septum and the location of the defect. In this view, the ultrasound probe is positioned beneath the xiphoid process, allowing for excellent imaging of the atria and the great vessels.

This view provides a comprehensive perspective of the heart structures, facilitating the identification of abnormal connections, particularly in the area where the vena cavae enter the right atrium. The modified subcostal view enhances the visualization of the abnormalities associated with sinus venosus ASD, including seeing the presence of anomalous pulmonary venous return, which can often accompany this type of defect.

Other views like the apical four chamber, parasternal long axis, and suprasternal notch views have their roles in echocardiography but do not provide the same level of detail for assessing the interatrial septum and the vicinity of the superior or inferior vena cava. The apical view might be limited in visualizing the anatomy clearly due to its orientation, and the parasternal long axis is primarily focused on the left ventricular outflow