Posterior interventricular groove

The ventricles of the heart are separated by two grooves, one on the anterior surface of the heart and the other on the posterior surface. The posterior interventricular groove (posterior longitudinal groove, posterior interventricular sulcus, inferior interventricular groove) is on the posterior and diaphragmatic surfaces of the heart near the right margin.

The posterior interventricular groove contains the posterior interventricular artery and middle cardiac vein.

Note that the green arrow in the figure below is pointing to the coronary groove. The middle cardiac vein can just be glimpsed in the figure below, indicating the position of the posterior interventricular groove.