Which cardiac chamber is most enlarged? Which features support this?
The left atrium is most enlarged. There is a double contour to the right heart border, splaying of the carina and prominence of the left atrial appendage.
Are there pulmonary vascular changes?
Yes, the pulmonary veins in the upper lobes, especially on the right are prominent.
Chest x-ray demonstrates cardiomegaly with features of left atrial enlargement (double contour on the right, splayed carina and enlarged left atrial auricle). The heart is also generally enlarged as are the pulmonary veins, particularly in the right upper zone.