Vena magna cordis

The great cardiac vein (left coronary vein) begins at the apex of the heart and ascends along the anterior longitudinal sulcus to the base of the ventricles. It then curves around the left margin of the heart to reach the posterior surface.

It merges with the oblique vein of the left atrium to form the coronary sinus, which drains into the right atrium. At the junction of the great cardiac vein and the coronary sinus, there is typically a valve present.

This is the Vieussens valve of the coronary sinus.It receives tributaries from the left atrium and from both ventricles: one, the left marginal vein, is of considerable size, and ascends along the left margin of the heart.