Right marginal vein of heart

The right marginal vein is a cardiac vein that drains the anterior wall of the right ventricle and typically runs along the right (acute) margin of the heart. This vein exhibits significant anatomical variability in its drainage pattern and is part of the cardiac venous system that returns deoxygenated blood from the myocardium to the right atrium.

The right marginal vein demonstrates considerable variation in its termination. In approximately 36% of cases, it joins with other tributaries to form the small cardiac vein, which then drains into the coronary sinus system. However, in the majority of cases (64%), the right marginal vein does not contribute to the small cardiac vein but instead joins the system of anterior cardiac veins, which drain directly into the right atrium independently of the coronary sinus. This anatomical variation has functional significance, as it diminishes the drainage function of the coronary sinus while increasing the importance of the anterior cardiac vein system.