You mean the great coronary vein and Marshall's vein? If so, then into the coronary sinus then to the right atrium through the valve of Thebesius!
Middle cardiac (and posterior vein of left ventricle) *both drain in coronary sinus*
Eustation tubes which drain into the back of the esophagus.
Empties into coronoary sinus which empties into the right atrium
Great Cardiac Vein. It, along with the middle and small cardiac veins return blood to the coronary sinus which returns the blood to the right atrium. A few small anterior cardiac veins return blood directly to the right atrium.
is a collection of veins joined together to form a large vessel that collects blood from the myocardium of the heart. It is present in humans and other animals. It receives blood mainly from the small, middle, great and oblique cardiac veins. It also receives blood from the left marginal vein and the left posterior ventricular vein. The anterior cardiac veins drain directly into the right atrium. (Some small veins drain into any of the four chambers of the heart.) It drains into the right atrium on the posterior, inferior surface, medial to the inferior vena cava opening.
superior venecava
Cardiac veins are blood vessels that carry deoxygenated blood away from the heart muscle. Included in these is the great cardiac vein, the middle cardiac vein, the anterior cardiac veins and the small cardiac vein.
If you had a great blood loss during the surgery, then this could of caused the Anemia.
The great cardiac vein is one of the largest veins in the body. It is located in the heart, leading away from the coronary sinus. It's function is to lead blood that has had the oxygen removed from it away from the heart.
The veins connected to the heart include the superior and inferior vena cava, which bring deoxygenated blood from the body to the right atrium, and the pulmonary veins, which return oxygenated blood from the lungs to the left atrium.
The coronary sinus and cardiac veins are structures that drain deoxygenated blood from the myocardium into the right atrium of the heart. This blood is then circulated to the lungs for oxygenation before returning to the heart.