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Coronary Anatomy
½ Loop and Circle
½ Loop – LAD and PDA
Circle – RCA and Circ
Rt A.V. Sulcus
85% Rt dominant
7-8% Balanced
7-8% Left dominant
Rt PDA Post Interventric
Groove
Right Coronary Artery
Right Coronary Artery
The RCA arises from the anterior right coronary sinus somewhat inferior to the origin of the LCA.
The RCA passes to the right of and posterior to the pulmonary artery and then downward in the
right atrioventricular groove toward the posterior interventricular septum.
In more than 50% of individuals, the first branch of the RCA is the conus artery, unless it (the
RCA) has a separate origin directly from the right coronary sinus.
The second branches usually consist of the sinoatrial node artery and several anterior branches that
supply the free wall of the right ventricle.
The branch to the right ventricle at the junction of the middle and distal RCA is called the acute
marginal branch. The distal RCA divides into the PDA and posterior left ventricular branches in a
right dominant anatomy
RAO
Lateral
Left Coronary Artery
Lad - Ant Intervent Groove
Circ – Post AV Groove
Left Coronary Artery
RAO
Left Coronary Artery
RAO
Left Coronary Artery
Left Coronary Artery
The Lt Main arises from the left posterior coronary sinus, is 5–10 mm long, and
does not vary in diameter.
The LCA passes to the left of and posterior to the pulmonary trunk and
bifurcates into the LAD and LCx arteries.
Occasionally, the LCA trifurcates into the LAD and LCx arteries and the ramus
intermedius.
The ramus intermedius has a course similar to that of the first diagonal branch of
the LAD artery to the anterior left ventricle.
The LAD artery passes to the left of the pulmonary trunk and turns anteriorly to
course in the anterior interventricular groove toward the apex.
It provides the diagonal branches to the anterior free wall of the left ventricle
and the septal branches to the anterior interventricular septum.
The LCx artery courses in the left atrioventricular groove and gives off obtuse
marginal branches to the lateral left ventricle. In a left dominant or codominant
anatomy, the LCx artery gives rise to the PDA or posterior left ventricular
branches
High Takeoff of Coronary Artery
Usually Asymptomatic
6% of Hearts
Right Coronary Artery
Of 126 nontraumatic sudden deaths in young adults, cardiac
abnormality was found in 64 cases (51%), with coronary artery
abnormalities being the most common cardiac abnormality
39 of 64 patients (61% )
Multiple Ostia
Typically either the RCA and the Conus branch arise separately,
or the LAD and LCx arteries arise separately with no Left Main
(0.4%)
Separate origins of right coronary Artery and conus branch
An aberrant conus artery arising
separately from the RCA is
particularly at risk for injury
from ventriculostomy or other
maneuvers performed during
heart surgery
Single Coronary Artery
Single ostium from the aortic trunk
Extremely rare - seen in only 0.0024%– 0.044% of the population
A single coronary artery may either follow the pattern of a normal RCA or LCA,
divide into two branches with distributions of the RCA and LCA, or have a
distribution different from that of the normal coronary arterial tree
Although a single coronary artery may be compatible with a normal life expectancy,
patients are at increased risk for sudden death if a major coronary branch crosses
between the pulmonary artery and the aorta.
In addition, proximal stenosis of a single coronary artery may be devastating if there is
an inability to develop collateral channels
Rt Coronary arising
from LAD
Single Coronary Artery
Low Risk
Rare
Follows Lad or RCX
High risk if Anomolous course
Poor collateral flow
RCA (Curved) arises from Lad (Straight)
Single Coronary Artery
High Risk Due to Pre- Aortic Route of RCA
Multiple Ostia
Typically either the RCA and the Conus branch arise separately,
or the LAD and LCx arteries arise separately with no Left Main
(0.4%)
Coronary CTA Technique
Heart rate approx 60 or less
Non contrast first for cardiac scoring
NTG prior to injection
80 cc contrast followed by 40 cc NS flush
Scans reconstructed at various stages of cardiac cycle 70-80%
best…late diastole
30%
40%
65%
75%
Anomalous Origin of the Coronary Artery from the Pulmonary Artery
(ALCAPA)
One of the most serious congenital coronary artery anomalies.
It has an estimated prevalence of one in 300,000 live births
Most affected patients show symptoms in infancy and early childhood.
Approximately 90% of untreated infants die in the 1st year of life
Most common form- the LCA arises from the pulmonary artery and the RCA arises
normally from the aorta (Bland-White-Garland syndrome)
Coronary angiography demonstrates collateral circulation between the RCA and LCA
and a coronary “steal”
Treatment of ALCAPA consists of re-creation of dual coronary perfusion.
Infantile ALCAPA, either
a) direct reimplantation of the anomalous LCA into the aorta or
b) creation of an intrapulmonary conduit from the left coronary ostia to the aorta
In adult type ALCAPA, ligation of the LCA from the pulmonary artery, combined with
coronary artery bypass grafting with use of the internal mammary artery or the
saphenous vein
ALCAPA Pre- Op
(Bland-White-Garland Syndrome)
Enlarged Rt. Coronary with
collaterals to LCA
RCA off Aorta..LCA off Pulm Artery
ALCAPA Post- Op
•LCA tied off from Pulm
Artery
•Lt. Int. Mammary Artery
connected to LCA
•RCA smaller
•Collaterals Less
Origin of the Coronary Artery or Branch from the Opposite or
Noncoronary Sinus and an Anomalous Course
Intra-Arterial
(A) has a high
risk of sudden
cardiac death
Anomolous Rt. From Lt
Sinus most commonly
follows intra-arterial
course with 30%
mortality
It has been postulated that, when
dilation of the aorta occurs during
exercise, the anomalous slit-like
ostium for the RCA in the left sinus
becomes narrower, possibly limiting
coronary blood flow and resulting in
myocardial infarction
Anomolous Coronary Origin
Anomolous Rt. From Lt Sinus most
commonly follows intra-arterial
course with 30% mortality
Intra-Arterial (A) has a high risk
of sudden cardiac death
LCA arising from RT Sinus with Pre-Pulmomic Course
Usually low risk
Myocardial Bridging
Myocardial bridging is caused
by a band of myocardial muscle
overlying a segment of a
coronary artery.
It is most commonly localized
in the middle segment of the
LAD
Compression of LAD during
systole
Can cause Sudden death
May need systolic
reconstruction to visualize
Duplication of LAD < 1 % Population
LAD arising from RT with Septal course
Left Circumflex arising from RCA
Retroartic
Coronary Artery Fistula
0.1% of Pop RCA>LCA
Coronary artery fistula is a condition in which a communication
exists between one or two coronary arteries and either
Cardiac chamber
RV 45%
Pulmonary artery
15%
Coronary sinus
LV/LA 10% RA 25%
Superior vena cava
Lt side mimics Aortic Insufficiency
Rt. Side left to right shunt
May lead to ischemia
<5%
Coronary Artery Fistula
Corrected Transposition
Coronary arteries originating from both
aortic sinuses. Note that the aorta (A) is
located anterior to and to the left of the
pulmonary artery (PA).
The ventricles with their respective atrioventricular valves (not shown) were
inverted; thus, the distribution of the
coronary arteries is reversed, in keeping
with the ventricular inversion.
The anterior aortic sinus corresponds to the
noncoronary sinus.
The morphologic LCA (white arrow) arises
from the right posterior aortic sinus and
supplies the pulmonary ventricle (anatomic
left ventricle).
The morphologic RCA (black arrow) arises
from the left posterior aortic sinus and
supplies the systemic ventricle (anatomic
right ventricle).