Coronary sinus
The coronary sinus is the largest cardiac venous structure. It returns the majority of the blood supply for the left ventricle to the right atrium.
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Gross anatomy
The coronary sinus courses along the posterior wall of the left atrium into the left atrioventricular groove. It normally drains into the right atrium. The ostium of the coronary sinus is partially covered by the Thebesian valve.
Veins draining into the coronary sinus are highly variable, but usually, include:
- great cardiac vein
- middle cardiac vein (posterior interventricular vein)
- small cardiac vein
- posterior vein of the left ventricle
- left atrial oblique vein (of Marshall)
- left marginal vein
Development
The coronary sinus develops from one of the two sinus horns of the sinus venosum. The other horn becomes part of the right atrium. The right venous valve of the sinus venosum develops into the thebesian valve and the Eustachian valve.
Variant anatomy
- the coronary sinus may act as a conduit between a persistent left superior vena cava and the right atrium
- rarely, the coronary sinus may drain into the left atrium, causing a left-to-right shunt (or right-to-left in cases of right heart failure)
Related pathology
The coronary sinus may be involved in a number of different procedures or pathologic processes:
- the coronary sinus is a good position for lead placement in biventricular pacing
- the coronary sinus may be an ablation target for some arrhythmia/dysrhythmias (e.g. Wolff-Parkinson-White syndrome)
- the coronary sinus rarely may have an abnormal connection to the left atrium on its way to the right atrium (unroofed coronary sinus), a rare kind of atrial septal defect
- associated with heterotaxy syndromes and persistent left-sided superior vena cava
Related Radiopaedia articles
Anatomy: Thoracic
- thoracic skeleton
- thoracic cage
- thoracic spine
- articulations
- muscles of the thorax
- diaphragm
- intercostal space
- intercostal muscles
- variant anatomy
- spaces of the thorax
- thoracic viscera
- tracheobronchial tree
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lungs
-
bronchopulmonary segmental anatomy (Boyden Classification) (mnemonic)
- left lung
- right lung
- variant anatomy
- lung parenchyma
- hilum
- pleura
-
bronchopulmonary segmental anatomy (Boyden Classification) (mnemonic)
-
heart
- cardiac chambers
- heart valves
- pectinate muscles
- cardiac fibrous skeleton
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coronary arteries
- coronary arterial dominance
- myocardial segments
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left main coronary artery (LMCA)
- ramus intermedius artery (RI)
-
circumflex artery (LCx)
- obtuse marginal branches (OM1, OM2, etc))
- Kugel's artery
-
left anterior descending artery (LAD)
- diagonal branches (D1, D2, etc)
- septal perforators (S1, S2, etc)
-
right coronary artery (RCA)
- conus artery
- sinoatrial nodal artery
- acute marginal branches (AM1, AM2, etc)
- inferior interventricular artery (PDA)
- posterior left ventricular artery (PLV)
- congenital anomalies
- innervation of the heart
- fetal circulation
- atrial septum
- endocardium
- myocardium
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pericardium
- epicardium
- epicardial fat pad
- pericardial space
- oblique pericardial sinus
- transverse pericardial sinus
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pericardial recesses
- aortic recesses
- pulmonic recesses
- postcaval recess
- pulmonary venous recesses
- pericardial ligaments
- esophagus
- thymus
- breast
- blood supply of the thorax
- arteries
- veins
- superior vena cava (SVC)
- inferior vena cava (IVC)
-
coronary veins
- cardiac veins which drain into the coronary sinus
- great cardiac vein
- middle cardiac vein
- small cardiac vein
- posterior vein of the left ventricle
- vein of Marshall (oblique vein of the left atrium)
- anterior cardiac veins
- venae cordis minimae (smallest cardiac veins or thebesian veins)
- cardiac veins which drain into the coronary sinus
- pulmonary veins
- thoracoepigastric vein
- lymphatics
- innervation of the thorax