The ostium of the left marginal vein is typically at the distal end of the coronary sinus.
In most human hearts we have observed a valve associated with the ostium as this venous
drainage enters the coronary sinus.
This cardiac vein returns deoxygenated blood (metabolic waste products) from the lateral
wall of the left ventricle.
Importance in device delivery:
Left heart pacing can be achieved via placing leads into the left marginal vein; in the
diseased heart this region of the heart will often be the region of latest ventricular
The left marginal veins are also referred to as lateral veins. This set of veins can be
further subdivided to antero-lateral, left lateral, and postero-lateral veins depending
on their position on the heart.