The great cardiac vein.

The great cardiac vein is the longest venous vessel of the heart; in the majority of our cases it originated at the lower third of the anterior interventricular sulcus (58%). The great and the middle cardiac veins merge at the apex of the heart, forming together with the coronary sinus into which they both empty, a complete venous ring around the left ventricle (13%). On reaching the area of the coronary sulcus, the great cardiac vein crosses the anterior interventricular branch and the circumflex branch of the left coronary artery forming the triangle of Brocq and Mouchet in which the vein is mainly superficial (61%). One, two or three anterior ventricular branches of the left coronary artery traverse this triangle; the relations of the vein and these arteries are very variable and practically unpredictable in 30% of the cases.