article was on coronary artery anatomy. During my first year of experience
of cardiac CT 5 years ago, while I was working on 4 slice CT scan, venous
filling was a major issue for overlap of arterial and venous structures;
now, with16 and 64 slice CT scanners that is now no longer an issue.
In spite of that I felt a short overview of Coronary Venous Anatomy is essential.
The venous circulation can be divided into three systems:
the coronary sinus and its tributaries, the anterior right ventricular
veins, and the thebesian veins.
A) The Coronary Sinus into which drains the large veins (which are important).
The coronary sinus predominantly drains the left ventricle and receives
approximately 85 percent of coronary venous blood. It lies within the
posterior atrioventricular groove and empties into the right atrium at
the lateral border of the triangle of Koch. The crescent-shaped thebesian
valve guards the orifice of the coronary sinus. The named tributaries
of the coronary sinus include the anterior interventricular vein, which
courses parallel to the left anterior descending coronary artery. Adjacent
to the bifurcation of the left main stem, the anterior interventricular
vein courses leftward in the atrioventricular groove, where it is referred
to as the great cardiac vein. It receives blood from the marginal and
posterior left ventricular branches before becoming the coronary sinus
at the origin of the oblique vein (of Marshall) at the posterior margin
of the left atrium. The posterior interventricular vein, or middle cardiac
vein, arises at the apex, courses parallel to the posterior descending
coronary artery, and extends proximally to the crux. Here, this vein drains
either directly into the right atrium or into the coronary sinus just
prior to its orifice. The small cardiac vein runs posterior through the
right atrioventricular groove.
Cardiac venous systems, which are small veins which drain into right atrium.
The anterior right ventricular veins travel across the right ventricular
surface to the right atrioventricular groove, where they either enter directly
into the right atrium or coalesce to form the small cardiac vein. As indicated,
this vein travels down the right atrioventricular groove, around the acute
margin, and enters into the right atrium directly or joins the coronary
sinus just proximal to its orifice. A relatively constant vein is right
marginal vein that follows the right margin of heart
The thebesian veins are small venous tributaries that drain directly into
the cardiac chambers. They exist primarily in the right atrium and right
The topographic separation does not indicate functional separation, the
two-system anastamose freely, particularly at cardiac apex, anterior interventricular
groove, and conus pulmonalis. Due to this extensive degree of collateralization
amongst these veins and the coronary arteries, and the paucity of valves
within coronary veins, enables the use of retrograde coronary sinus cardioplegia
for intraoperative myocardial protection.
Coronary venous anatomic mapping
may aid in planning of transvenous biventricular pacing lead placement
and other invasive procedures. .
Coronary sinus is used as
landmark in catheter angiogram for tracing circumflex artery.