Left border of heart
The left border of heart (or left margin, or obtuse margin) is shorter than the right border, full, and rounded: it is formed mainly by the left ventricle, but to a slight extent, above, by the left atrium.
|Left border of heart
Sternocostal surface of heart.
Heart seen from above.
- MedEd at Loyola medicine/pulmonar/cxr/atlas/silouhette2.htm