The coronary sinus is the main drainage channel of venous blood from the myocardium. It is the main derivative of the left horn of the sinus venosus of fetal life. It is situated within the atrioventricular groove on the posterior surface of the heart between the left atrium and ventricle. It commences towards the left of the groove at the point at which it receives the oblique vein of the left atrium. It passes to the right and inferiorly to terminate by draining into the right atrium at the coronary sinus orifice.
The coronary sinus is drained into by a number of smaller veins; typically, from left to right along its course, the:
Last reviewed 01/2018