The inferior or diaphragmatic surface of the heart forms a roughly straight plane or slight concavity that projects to the left and slightly inferiorly to the apex of the heart. It lies superior to the central tendon of the diaphragm and at its lateral projection, the muscular part of the left hemidiaphragm.
The inferior surface consists of:
- posterior: the right atrium at its junction with inferior vena cava; separated from ventricles by continuation of coronary sulcus
- right: right ventricle - occupies about third of the diaphragmatic surface
- left: left ventricle - roughly two thirds of the diaphragmatic surface
Both the ventricles are separated by the posterior interventricular groove in which the posterior interventricular artery and middle cardiac vein run.