Vessel
Coronary sinus
A collecting channel for most cardiac venous blood
High-yield
The coronary sinus carries most, but not all, cardiac venous return.
Overview
The coronary sinus receives major cardiac veins in the posterior atrioventricular groove and opens into the right atrium. It continues from the great cardiac vein near the entry of the oblique left atrial vein. Some myocardial blood uses other routes directly into cardiac chambers.
Reference facts
- Origin
- Continuation of the great cardiac vein near the oblique left atrial vein's junction
- Course
- Across the posterior AV groove toward its right atrial opening
- Branches
- Great and middle cardiac veins, variable small cardiac vein and left ventricular or atrial tributaries
- Supplies
- Collects venous blood from myocardium; it is not an arterial supply
- Drains to
- Right atrium near the inferior caval and tricuspid openings; an ostial Thebesian valve may be present
Clinical correlation
Its opening and tributaries provide access for some cardiac devices. Variable venous valves and congenital connections can alter that access or enlarge the sinus.
Frequently asked questions
Where does the coronary sinus originate?
The coronary sinus arises from the continuation of the great cardiac vein near the oblique left atrial vein's junction.
What does the coronary sinus supply?
Collects venous blood from myocardium; it is not an arterial supply.
Where does the coronary sinus drain to?
Right atrium near the inferior caval and tricuspid openings; an ostial Thebesian valve may be present.
What are the branches of the coronary sinus?
Branches of the coronary sinus include the great and middle cardiac veins, variable small cardiac vein and left ventricular or atrial tributaries.