X-ray chest PA view showing biatrial enlargement

X-ray chest PA view showing biatrial enlargement

X-ray chest PA view showing biatrial enlargement. Right atrial enlargement is manifest as the enlargement of the cardiac outline towards the right side. Left atrial enlargement is seen as a double atrial contour (shadow within shadow) within the right heart border. Straightening of the left heart border is also partly due to the enlargement of the appendage of left atrium and partly due to obliteration of pulmonary bay by mildly enlarged main pulmonary artery. RA: Right atrium; LA: Left atrium; MPA: Main pulmonary artery segment; LAA: Left atrial appendage