Right border of heart

The right border of the heart is only a radiologic feature that is formed on a standard posteroanterior (PA) chest radiography by the right atrium. The right ventricle, while the most anterior cardiac chamber, does not contribute to the right border on the PA view; instead, it forms the majority of the anterior (sternocostal) surface of the heart.

The right border of the heart was previously described in Gray's anatomy (1) as :"The right margin of the heart is long is long, and is formed by the right atrium above and the right ventricle below. The atrial portion is rounded and almost vertical; it is situated behind the third, fourth, and fifth right costal cartilages about 1.25 cm. from the margin of the sternum. The ventricular portion, thin and sharp, is named the acute margin; it is nearly horizontal, and extends from the sternal end of the sixth right costal cartilage to the apex of the heart." But according to the Terminologia Anatomica 2, this description corresponds to the right surface of the heart.