Tags: Anatomical Structure.
The right margin of the heart (right border of heart) 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 coastal cartilage to the apex of the heart.
