The coronary sinus () is the largest vein of the heart.
It drains over half of the deoxygenated blood from the heart muscle into the
right atrium. It begins on the backside of the heart, in between the
left atrium, and
left ventricle; it begins at the junction of the
great cardiac vein, and
oblique vein of the left atrium. It receives multiple tributaries. It passes across the backside of the heart along a
groove between left atrium and left ventricle, then drains into the right atrium at the orifice of the coronary sinus (which is usually guarded by the
valve of coronary sinus).
Structure
Origin
The coronary sinus arises upon the posterior aspect of the heart between the
left atrium, and
left ventricle.
The coronary sinus commences at the union of the
great cardiac vein, and the
oblique vein of the left atrium.
The origin of the coronary sinus is marked by the
Vieussens valve of the coronary sinus which is situated at the endpoint of the great cardiac vein.
Course
The coronary sinus runs transversely in the left
atrioventricular groove (coronary sulcus) on the posterior aspect of the heart.
The sinus, before entering the right atrium, is considerably dilated - nearly to the size of the end of the little finger.
Fate
The coronary sinus drains through the posterior wall of right atrium at the orifice of the coronary sinus.
This orifice is located at the posteroinferior aspect of the right atrium, just medial
and to the left of the orifice of
inferior vena cava,
and between the inferior vena cava and the
right atrioventricular orifice/tricuspid valve. The orifice is usually guarded by the
valve of coronary sinus (a thin, crescent-shaped valve located on the anteroinferior part of the opening into the right atrium).
Tributaries
The coronary sinus receives blood mainly from the
small
Small means of insignificant size
Size in general is the Magnitude (mathematics), magnitude or dimensions of a thing. More specifically, ''geometrical size'' (or ''spatial size'') can refer to three geometrical measures: length, area, or ...
,
middle,
great
Great may refer to:
Descriptions or measurements
* Great, a relative measurement in physical space, see Size
* Greatness, being divine, majestic, superior, majestic, or transcendent
People
* List of people known as "the Great"
* Artel Great (bo ...
,
and
oblique cardiac veins. It also receives blood from the
left marginal vein and the
left posterior ventricular vein.
*
Great cardiac vein (run upwards in the
anterior interventricular sulcus to the left
atrioventricular groove to form the coronary sinus;
*
Middle cardiac vein (ascends
posterior interventricular sulcus to drain into coronary sinus);
*
Small cardiac vein (accompanies
right coronary artery in the right atrioventricular groove to drain into the right side of the coronary sinus;
*
Posterior vein of left ventricle (accompanies the
left marginal artery, ascends the posterior wall of left ventricle to drain into the coronary sinus);
*
Oblique vein of left atrium.
All veins that empty into the coronary sinus except for the oblique vein of the left atrium have valves at their junction with the coronary sinus.
The
anterior cardiac veins do not drain into the coronary sinus but drain directly into the right atrium. Some small veins known as
Thebesian veins drain directly into any of the four chambers of the heart.
Microanatomy
The wall of the coronary sinus is partly muscular.
Function
The coronary sinus is responsible for venous return of about 55% of the cardiac blood supply.
Clinical significance
Electrodes can be inserted into and through the coronary sinus to study the
of the heart. This includes for a coronary sinus electrogram.
The coronary sinus connects directly with the right atrium. It will dilate as a result of any condition that causes elevated right atrial pressure, such as pulmonary hypertension. Dilated coronary sinus is also seen in some congenital cardiovascular conditions, such as persistent left superior vena cava, and total anomalous pulmonary venous return.
[Gupta A, Mishra A, Shrivastava Y. "Repair of intracardiac total anomalous pulmonary venous return". ''Multimed Man Cardiothorac Surg.'' 2021 Mar 8;2021. . ]
In
Cardiac Resynchronization Therapy (CRT) procedures, a critical step involves the insertion of a pacing lead into the coronary vein system. However, the anatomical configuration of the coronary sinus (CS) exhibits significant variability, necessitating that cardiologists assess and evaluate its characteristics during the procedure. Complications may arise when tactical decisions must be made before the endovascular implantation of the left ventricular electrode, which can be challenging due to the unique anatomical features of the CS.
Additional images
File:Gray493.png, Interior of heart, viewed anteriorly (opening of coronary sinus is labeled)
File:Gray491.png, Back (posterior) side of the heart, with coronary sinus (blue) labeled
See also
*
Coronary arteries
The coronary arteries are the arteries, arterial blood vessels of coronary circulation, which transport oxygenated blood to the Cardiac muscle, heart muscle. The heart requires a continuous supply of oxygen to function and survive, much like any ...
*
Percutaneous coronary intervention
*
Cardiac skeleton
References
External links
* – "Posterior view of the heart."
*
{{Authority control
Thoracic veins
Veins of the torso