ANATOMY OF CORONARY
CIRCULATION
mangala_kumari@imu.edu.my
Learning Outcomes
To explain the origin and course of right and left
coronary arteries.
To name the branches of right and left coronary
arteries.
To name the areas supplied by the right and left
coronary arteries.
To describe the coronary sinus and its tributaries.
To identify the right and left coronary artery
branches on the coronary angiogram.
To understand certain coronary artery anomalies.
Coronary arteries
Branches of ascending aorta
Right coronary artery – arises from right coronary sinus
of Valsalva which lies anteriorly (anterior sinus of
Valsalva / anterior aortic sinus)
Left coronary artery – arises from left coronary sinus of
Valsalva (left sinus of Valsalva / left aortic sinus)
Aortic valve- three leaflets, each having a cusp or cup-like
configuration. Left coronary cusp (L), Right coronary cusp (R)
and Posterior non-coronary cusp (N).
Just above the aortic valves there are anatomic dilations of
the ascending aorta, known as the sinus of Valsalva.
Right coronary artery
Right coronary sinus of Valsalva
Between pulmonary trunk and right auricle
Right A-V groove (Anterior part)
(coronary groove)
Winds round inferior border
Right A-V groove (Posterior part)
(reach the crux)
Right coronary artery Branches
Sinuatrial (SA) nodal br. (In
40% originate from Cx)
Conus a. (In 20 -30% direct
br. of aorta)
Right marginal br. (acute
marginal a./AM)
PDA/Posterior descending a.
(post. interventricular a.) –
20% cases from CX
Atrioventricular (AV) nodal br.
Conus a.
Left coronary artery
Left coronary sinus of Valsalva
Passes behind pulmonary trunk
Appears between pulmonary trunk &
left auricle
LAD/ left anterior
Circumflex A.
descending A. (Ant.
Interventricular A.) Winds –left border
(Ant. interventricular
groove)
Left A-V groove
Left coronary arteryBranches
LAD/ Left ant. descending a.
(Ant. interventricular a.)
Diagonal a.
Circumflex br.
Marginal br.
Coronary Arteries
Coronary Dominance
Dominance refers to whether the PDA
originates from the RCA (right dominant), CX
(left dominant), or both (co-dominant)
Approximately 80% - right dominant. RCA
at crux bifurcates into the PDA and a
postero-lateral branch. The PDA courses in
the posterior ventricular septum giving origin
to the AV nodal artery and posterior
interventricular branch.
In left dominance, the PDA originates from
the CX.
In co-dominance, there are right and left
PDAs originating from the RCA and CX.
Areas supplied by:
Right coronary artery
Right atrium
Right ventricle (most
part)
Part of left ventricle
Posterior 1/3rd of
interventricular septum
SA node
AV node
Left coronary artery
Left atrium
Left ventricle (most
part)
Part of right ventricle
Anterior 2/3rd of
interventricular septum
AV bundle
Veins of the heart
From the cardiac capillaries, blood
flows back to cardiac chambers
through venules, which in turn
coalesce into cardiac veins.
60% venous blood is collected and
drained into right atrium- Coronary
sinus
40% venous blood drained by
Venae cordis minimi (Thebesian
veins) – drain into different
chambers of heart
Anterior cardiac veins – directly
drain into right atrium
Coronary sinus
2-3 cm long, lies in the post. part
of A-V groove.
Begins in left part of A-V groove
where it receives the great
cardiac vein.
Passes downwards to the right
side of A-V groove.
Opens into the sinus venarum of
right atrium
Opening is guarded by
incomplete semilunar valve
Coronary sinus –
Tributaries
Great cardiac vein - runs along anterior
interventricular groove.
Receives left marginal vein close to
termination.
Middle cardiac vein – runs along
posterior interventricular groove.
Small cardiac vein - lies in A-V groove
between right atrium and right ventricle
Receives right marginal vein.
Posterior vein of left ventricle
Oblique vein of the left atrium
Coronary angiogram
Right coronary artery
http://www.youtube.com/watch?v=Eoq9yrT-Ejk
Coronary angiogram
Left coronary artery
70% stenosis in third obtuse marginal
branch (arrow head)
stenosis of proximal first diagonal branch
(open arrow)
Coronary anomalies
Anomalous origin of the
LCA from the right sinus of
Valsalva and the LCA
courses between the aorta
and pulmonary artery.
This interarterial course
can lead to compression
of the LCA (yellow arrows)
resulting in myocardial
ischemia.
Coronary anomalies
ALCAPA - Origin of the LCA from the
pulmonary artery.
Results in the left ventricular
myocardium being perfused by
relatively desaturated blood under low
pressure, leading to myocardial
ischemia.
ALCAPA is a rare, congenital cardiac
anomaly accounting for approximately
0.25-0.5% of all congenital heart
diseases.
Approximately 85% of patients
present with clinical symptoms of CHF
within the first 1-2 months of life.
Anomalous Left Coronary
Artery arising from the
Pulmonary Artery
Coronary anomalies
Myocardial bridging
Commonly observed of the LAD
The depth of the vessel under
the myocardium is more
important that the length of the
myocardial bridging.
Fistula
Large LAD giving rise to a
large septal branch that
terminates in the right ventricle
(blue arrow).