The document provides information on the embryogenesis, anatomy, variations, and anomalies of the coronary arteries. It discusses how the coronary arteries develop from an initial subepicardial plexus that invades the myocardium. The two main coronary arteries, the left and right, originate from the aortic sinus and have distinct branches that supply different regions of the heart. There are various anatomical variations in the origins, courses and distributions of the coronary arteries between individuals. Coronary artery anomalies can also occur during development.

1. CORONARY ARTERY
AND ANOMALIES:
DR SANDIP GURAGAIN

2. OUTILNES OF TOPIC:
▪ Morphogenesis
▪ Coronary artery anatomy
▪ Variations of coronary artery
▪ Regional supply
▪ CA anomalies

3. Etymology:
Coronary
▪ The word corona is a Latin word meaning
"crown", from the Ancient Greek (korōnè,
“garland, wreath”).
▪ The word arterie in Anglo-French (artaire
in Old French, and artērium in Latin)
means "windpipe" and "an artery

4. Coronary circulation:
▪ First two branches of aorta.
▪ Sub epicardial in nature.

5. ▪ Both subepicardial CAs and veins are extracardiac in origin, deriving from epicardial
cells.
▪ Begins with the formation of a plexus like vasculature located in the subepicardium,
which invades the myocardium and develops small vessels and capillaries
▪ Muscularization of the coronary arteries begins from the proximal coronary arterial
trunks.
Embryogenesis:

6. Embryogenesis:
▪ Earlier, the myocardial blood supply derives
directly from the ventricular cavities through the
inter-trabecular spaces lined by the endocardium.
▪ With myocardium impaction; it consists of vessels
with the endothelium derived from the sub-
epicardium.

7. Contd…
▪ A subepicardial network of cells
(“bioepicardial organ”) surrounds the
orifices of the great arteries (peritruncal
ring) and eventually connects with the
facing aortic sinuses.
▪ Why the primitive subepicardial coronary
arterial vasculature tends to connect with
the facing aortic sinuses, instead with
facing pulmonary sinuses, is still unknown

8. Ingrowth vs Outgrowth:
▪ Two hypotheses:
▪ Outgrowth hypothesis:
▪ Development of sprouts or buds from the aortic wall of facing sinuses, capturing the
peritruncal ring of coronary subepicardial arterial vasculature

9. Contd:
▪ Ingrowth hypothesis:
▪ The prongs of the peritruncal ring penetrate
the aortic wall and make contact with the
endothelial lining of the aorta.
▪ Rcent investigation showed
▪ Prospective CA endothelial cells do not bud
from the aortic root, but instead grow into the
aortic wall from an aortic peritruncal plexus
to connect to the systemic circulation.
▪ It is done most likely under the guidance of
vascular endothelial growth factor (VEGF-C)
and periaortic cardiomyocytes

10. Contd:
▪ Formation of the left CA precedes the right
CA.
▪ Tunica media of the CAs does not derive
from the neural crest.
▪ Septation of the arterial pole of the heart
(42 days in the human embryo) precedes
the appearance of coronary ostia
▪ Septation therefore cannot be responsible
for the final position of coronary orifices.

11. Coronary artery Anatomy:

12. Origin:
▪ Aortic sinus
- 3 in number
Right coronary sinus -anterior
Left coronary sinus – left anterior
Non coronary sinus – left posterior

13. CA origin:
▪ The ostia normally originate about two-
thirds the distance from the aortic annulus
to the sinotubular junction and about
midway between the aortic valve
commissures.
▪ LCA ostium ~ 4mm
▪ RCA ostium~ 3.2mm
▪ The right coronary artery arises nearly
perpendicularly from the aorta, the left
arises at an acute angle

14. Clinical correlation:
▪ Ostial stenosis most commonly results from atherosclerosis and degenerative
calcification of the aortic sinotubular junction, which often overlies the right
aortic sinus.
▪ Less often it is caused by aortic dissection or by aortitis associated with syphilis
or ankylosing spondylitis.
▪ Stenosis of the right coronary ostium is much more frequent than that of the left.
▪ Iatrogenic ostial injury can complicate coronary angiography, intraoperative
coronary perfusion, or aortic valve replacement.
▪ Atherosclerosis or thrombosis of the most proximal portion of either coronary
artery can mimic true ostial stenosis.

15. RIGHT CORONARY ARTERY
ORIGIN
▪ Arises in right sinus of valsalva- below origin of
LCA
COURSE
▪ between the pulmonary conus and right atrium
▪ Anteriorly and inferiorly under the right atrial
appendage
▪ Along the right AV groove
▪ To reach the acute margin of heart

16. RIGHT CORONARY ARTERY
▪ Turns posteriorly and inferiorly towards crux of
the heart
▪ Divides into
- posterior descending coronary artery
(PDA)
- posterolateral ventricular branch (PLB

17. RIGHT CORONARY ARTERY
1. Conus branch
2. SA nodal branch
3. Right ventricular branches
4. Right atria artery
5. Acute marginal artery
6. AV nodal artery
7. Posterior descending artery
8. Posterolateral artery

18. RIGHT CORONARY ARTERY
▪ Length 120-140 mm
▪ Diameter 1.5-5.5 mm
▪ Supplies
▪ Right atrium
▪ Ventricles
▪ Greater part of the right ventricle, except the area adjoining the
anterior interventricular groove.
▪ A small part of the left ventricle adjoining the posterior
interventricular groove.
▪ Posterior part of the interventricular septum.
▪ Whole of the conducting system of the heart except a part of the left
branch of the AV bundle.

19. CONUS BRANCH:
- Third coronary
- Infundibular
- Arteria of Vieussens
• First branch –50- 60%
• Separate ostium – 21-30%
• Moves away from the main artery,
proceeding ventrally, encircling the
RV outflow at the level of pulmonary
valve
• Supplies the pulmonary outflow
tract

20. SA NODAL ARTERY
▪ arises from– RCA-55-65%,LCX -35-45%
▪ opposite direction to the conus branch
▪ Divides into two rami
- one recurrent branch which supplies the
SA node
- the other runs posteriorly a left atrial
branch

21.  VENTRICULAR BRANCH
▪ one or more ventricular branches arising in the AV groove.
▪ Often reach interventricular sulcus and anastomose with branches
of LAD when occluded.
 RIGHT ATRIAL BRANCH
▪ originates at about the level of acute marginal artery travels in
opposite direction towards right heart border
▪ receives branches from SA nodal artery and bypasses obstruction
in proximal portion of the RCA.

22. ACUTE MARGINAL:
▪ Relatively large and constant vessel
▪ Arises at lower aspect of right atrium just
before or at the acute margin of the heart
▪ Travels along the acute margin from base
to apex

23. AV NODAL BRANCHES:
▪ It arises from RCA where it forms a characteristic inverted U curve
as the artery passes in the interventricular sulcus around the
interventricular vein.

24. ▪ Posterior descending artery(70-85%)
-courses in the inferior interventricular groove
-gives rise to a number of small inferior septal
branches supplying lower part of IVS
and interdigitate with superior septal
branches from LAD
▪ Posterolateral branches
-After giving rise to PDA ,the RCA continues
beyond the crux cordis as the right
posterior AV branch terminating in one or
several posterolateral branches
- supply the diaphragmatic surface of the LV

25. Angiographic divison of RCA:
▪ Proximal - Ostium to 1st main RV branch
▪ Mid - 1st RV branch to acute marginal
branch
▪ Distal - acute margin to the crux

26. LEFT CORONARY ARTERY:
ORIGIN & COURSE:
- Left coronary sinus of Valsalva, just below the
sinotubular junction
- Courses to the left beneath the left atrial
appendage, posterior to RVOT
- Branches to LAD and LCX
- Trifurcates in 1/3rd – Ramus Intermedius
- Rarely, no LM- separate ostia for each branch

27. LEFT CORONARY ARTERY:
▪ Areas Supplied
▪ Left atrium
▪ 2 Ventricles
▪ Greater part of the left ventricle, except the
area adjoinin the posterior interventricular
groove.
▪ A small part of the right ventricle adjoining
the anterior interventricular groove.
▪ Anterior part of the interventricular septum
▪ A part of the left branch of the AV bundle

28. LEFT CORONARY ARTERY:
▪ 10-25mm(up to 30mm) length &
2-6mm(up to 10mm diameter)
▪ Trifurcates in 1/3rd : Ramus
intermedius/ median artery/ left
diagonal artery/straight LV artery
▪ RI: follow the course of a
circumflex marginal branch

29. LEFT ANT DESCENDING ART:
▪ Length 100-130 mm
Diameter 2-5 mm
▪ Runs anteriorly and inferiorly
▪ to left of pulmonary trunk
▪ in the anterior interventricular
groove
▪ to the apex of the heart
▪ In 22%, does not reach the
apex

30. LEFT ANT DESCENDING ART:
▪ BRANCHES
1. Diagionals
2. Septals
3. RV branches
4. Terminal branches

31. DIAGONALS:
▪ 1st branch
▪ 2-9 in number
▪ Supply : LV Free wall

32. SEPTALS:
▪ CHARACTERISTICS
▪ Greater calibre and length of cranial
septals
▪ Less tortuosity, branching 90º from LAD
▪ Relative lack of motion
▪ Runs along septum from front to back and
in caudal direction
▪ VARY IN NUMBER

33. RV BRANCHES
▪ I or more branches
▪ Highest – form Vieussens anastomosis at level
of pulmonary artery
▪ Other branches- anastomose with RCA branches
to RV

34. TERMINAL BRANCHES:
▪ Apical branches
▪ Usually 2 branches can be seen
▪ Recurrent posterior-supplies
diaphragmatic portion
▪ Recurrent lateral-supplies lateral aspect
of apex

35. ANGIOGRAPHIC CLASSIFICATION OF LAD:
▪ Type 1-small caliber vessel reaches only 2/3rd
of way from base of heart to apex,more
prevalent in women
▪ Type 2-larger caliber reaches the apex of LV
▪ Type 3-extends from base to apex wraps
around the diaphragmatic surface of LV where
it augments the perfusion pattern of PDA.

36. ANGIOGRAPHIC DIVISON OF LAD:
▪ Proximal
▪ Ostium to 1st major septal perforator
or 1st diagonal artery whichever is
first
▪ Mid
▪ 1st perforator to 2nd diagonal (90
degree angle)
▪ Distal
▪ D2 to end

37. LEFT CIRCUMFLEX ARTERY:
▪ ORIGIN
▪ -from distal LMCA
▪ COURSE
▪ Runs posteriorly along the AV
groove to reach the crux

38. LEFT CIRCUMFLEX ARTERY:
BRANCHES
1. Obtuse marginal
2. Posterolateral branches
3. SA nodal branch (40%)
4. PDA (15%)

39. LEFT CIRCUMFLEX ARTERY:
▪ Divides into two parallel branches
▪ Upper- atrial circumflex- atrial wall
▪ Lower – ventricular branch
▪ Obtuse marginal- largest and most constant
branch
- runs along ventricular wall posteriorly to
reach apex
▪ Lcx runs around the AV groove and gives the
posterolateral branches
▪ Reaches crux and continues in posterior
interventricular sulcus as PDA in 15%

40. ANGIO CLASSIICATION OF LCX;
▪ Proximal - Ostium to 1st major obtuse
marginal branch
▪ Mid - OM1 to OM2
▪ Distal - OM2 to end

41. CORONARY DOMINANCE
▪ The artery gives rise to the PDA and the posterolateral (PL)
branches represents the dominant coronary artery.
▪ Dominance is right in 80% of human hearts, left in 10%, and
shared in 10%.
▪ Supplies the posterior (inferior) part of the ventricular septum and
often part of the posterolateral (inferolateral) wall of the left
ventricle

42. RIGHT DOMINANCE
▪ The posterior descending coronary artery is a branch of the right
coronary artery

43. LEFT DOMINANCE:
▪ The posterior descending artery is a branch of the left coronary
artery

44. BALANCED DOMINANCE:
▪ WHEN PDA IS GIVEN BY RCA & PLV IS GIVEN BY LCX
▪ ~10%

45. Basic principle of coronary classification:
• Name of coronary artery assigned not according to site of origin or proximal course
• It is according to dependent territory
Coronary artery anomalies: an
entity in search of identity ; Paolo
Angelini; Circulation. 2007.

46. Regional supply of CAs:
1. Clinical Methods in Cardiology By Soma Raju, Second
Edition, orient longman

47. A 17-segment model for the 2-dimensional transthoracic echocardiography

48. WHAT IS NORMAL?
Coronary artery anomalies: an entity in search
of identity ; Paolo Angelini; Circulation. 2007

49. VARIATIONS IN CORONARY ARTERY ANATOMY
▪ DEFINITION:
▪ VARIANT: an alternative, relatively unusual morphological feature
when present in >1% of the population
▪ ANOMALY: when the morphological variation is present in <1% of
the population

50. LEVEL OF VARIABILITY:
▪ Ostium
▪ Size
▪ Proximal course
▪ Mid-course
▪ Intramyocardial ramifications
▪ Termination

51. CORONARIY ANOMALIES:
▪ The prevalence of coronary artery anomalies in patients
undergoing coronary angiography averages 1% to 5%.
▪ Despite being rare in the general population, CAAs are the second
most common cause of sudden cardiac death (SCD) among young
athletes.

52. PREVALENCE:

53. CLASSIICATIONS:
ATLAS OF CARDIAC CATHEERISATION &INTERVENTIONAL CARDIOLOGY MOSCUCCI ET AL. 2019

54. ATLAS OF CARDIAC CATHEERISATION &INTERVENTIONAL CARDIOLOGY MOSCUCCI ET AL. 2019

55. ATLAS OF CARDIAC CATHEERISATION &INTERVENTIONAL CARDIOLOGY MOSCUCCI ET AL. 2019

56. ATLAS OF CARDIAC CATHEERISATION &INTERVENTIONAL CARDIOLOGY MOSCUCCI ET AL. 2019

58. Congenital Atresia of Coronary Ostium
▪ Coronary ostial hypoplasia or atresia can occur as an isolated
lesion or as a concomitant anomaly with other CAAs.
▪ The life expectancy depends on the presence of collateral
circulation from other vessels that can supply the distal coronary
bed.

59. Contd:
Coronary orifice
 below the cuspal margin:
10% RCS
15% LCS
 above sinotubular junction 6%
Significance: difficult cannulation
: surgical significance

60. Shepherd’s-crook RCA
▪ Acute superiorly angled take-off of the RCA from the aorta.
▪ Difficult RCA lesion angioplasty

61. Anomalous Origin of Coronary Artery
▪ Coronary arteries with ectopic origin.
▪ Arise either/or from
▪ The wrong sinus of Valsalva (e.g., the Cx artery arising from the
right coronary sinus).
▪ Different structure, including the pulmonary artery (PA), a branch
of another coronary artery, or even a ventricular chamber.
▪ The course of the anomalous coronary arteries can be assessed by
angiography in the RAO view.

62. Contd:
▪ The LCA arising from the
right aortic sinus usually
follows one of these four
courses:
▪ interarterial,
▪ retroaortic,
▪ prepulmonic,
▪ transseptal

63. ▪ The interarterial course of an anomalous LCA from the right sinus
is associated with SCD during or shortly after exercise in young
individuals.
▪ The hemodynamic mechanism unclear.
▪ Distention of the aortic root and the pulmonary trunk
▪ Exacerbate the preexisting angulation of the anomalous
coronary artery,
▪ Compression of the coronary artery lumen.

64. ▪ Origin of the RCA from the left aortic sinus with
an interarterial course is associated with
myocardial ischemia and SCD
▪ Once this anomaly is diagnosed, CABG is
recommended.
▪ Anomalous pulmonary origin of any coronary
artery (APOCA) is a very rare occurrence.
▪ If all three coronary arteries arise from the PA,
prognosis is poor; patients with this anomaly
usually die within the first month of life.

65. A A
B

66. ALCAPA:
▪ Anomalous origin of the LCA from PA
(ALCAPA), aka Bland-White-Garland
syndrome, and represents the most
common APOCA.
▪ Almost 90% of patients with this CAA die
during the first year of life.
▪ Only very few, with extensive collateral
circulation from the RCA, survive into
adulthood.
▪ If diagnosed in time, the preferred
treatment for APOCA is CABG or unroofing
and re-implantation (with or without a
patch)

67. Trifurcaing LMCA:
▪ Ramus intermedius- variant coronary artery
resulting from trifurcating LMCA
▪ 15-30% of population
▪ Course similar to obtuse marginal branch of
left circumflex or diagonal branches of LAD
▪ Significance:
▪ if RI is involved in atherosclerotic lesion, more
likely that LAD or Lcx is also involved
▪ stent deployment has poor support, prone for
mobilisation and migration

68. CA ECTASIAs:
▪ Dilated more than 1.5 times the normal adjacent coronary artery
▪ 1-5% in angiographic series

69. ABSENT LMCA:
▪ Lack of an LMCA is the most common form of
congenital coronary absence
▪ Rate of 0.41% to 0.67% in the general
population.
▪ LAD and Cx arteries simply arise directly from
the left sinus of Valsalva with separate origins.
▪ This anomaly is considered a benign condition
and is an occasional finding during coronary
angiography.
▪ The congenital absence of either the Cx or the
RCA has been reported and associated with a
benign prognosis.

70. HYPOPLASIA:
▪ Defined as the maldevelopment of at least one of the major
epicardial arteries or its branches.
▪ One, two, or all three coronary territories can be involved.
▪ Usually have a small diameter and a shortened course.
▪ A luminal diameter of less than 1.5 mm in a major epicardial
vessel, with no nearby compensatory branches, has been proposed
as the threshold for diagnosis.
▪ The prognosis of single-vessel hypoplasia of the Cx or RCA is
relatively good, but SCD can occur in two-vessel hypoplasia

71. ANAMOLOUS TERMINATION:
CAFs:
▪ Congenital coronary artery fistulas (CAFs) are rare anomalies
▪ Incidence :~0.002%(Ggen popn)& 0.3% to 0.8% of patients
undergoing coronary angiography for any indication.
▪ Abnormal direct communication between one or more coronary
arteries with another major vessel or a chamber, such as the vena
cava, left or right ventricle, pulmonary vein, or PA.
▪ CAFs can originate from any of the major epicardial vessels and
involve the RCA in 33% to 55%, the LAD in 35% to 49%, and the Cx
in 17% to 18% of cases

72. Coronary fistula:
▪ 4% to 18% of CAFs: Simultaneous
involvement of both system.
▪ Most of the fistulas drain into low-pressure
structures, such as the right ventricle (40%),
right atrium (26%), PA (17%), coronary sinus
(7%), and superior vena cava (1%).
▪ Coronary angiography is the gold standard
for the diagnosis of CAFs.
▪ Approximately 50% of patients with CAF are
asymptomatic.
▪ Common symptoms are dyspnea, fatigue,
palpitation, and chest pain CHF, arrhythmias,
SCD

73. Myocardial bridging
▪ Rare; in long term it can lead to local coronary
damage.
▪ Myocardial bridging consists of a segment of an
epicardial artery that descends into the myocardium
for a variable distance .
▪ It occurs in approximately 5% to 10% of patients and
usually involves the LAD.
▪ As it runs in the myocardium, during systole appears
as a narrowing on the angiogram; Narrowing
disappears during diastole.
▪ Although not thought to be of any hemodynamic
significance.
▪ C/F: angina, arrhythmia, depressed LV function,
myocardial stunning, early death after cardiac
transplantation, and .
▪ Rx: βB;srgry

74. CORONARY SPASMS:
▪ Constriction of the smooth muscle cells in the vessel
wallDynamic reversible focal restriction or occlusion of a
coronary artery
▪ Can cause Prinzmetal angina and lead to transitory ECG
changes.
▪ Cigarette smoking, cocaine use, alcohol, intracoronary
irradiation, and administration of catecholamines promotes
focal coronary spasm often associated with chest pain and
ECG changes.
▪ Intracoronary nitroglycerin /Acetylcholine (ACh)is used to
relieve the spasm
▪ In the presence of endothelial dysfunction, cells cannot
produce NO in response to ACh, resulting in local
vasoconstriction.
▪ Hyperventilation :less sensitive test compared with the
others.
▪ Dx:clinical features and the response to treatment with
nitrates and calcium channel blockers.

76. Clinical aspects:
▪ During cardiac operations, cardioplegic solution can be
administered retrograde into the coronary sinus.
▪ The coronary veins, via the coronary sinus, provide access to
percutaneous epicardial mapping and pacing of the ventricles and
ablation of subepicardial arrhythmogenic foci
▪ In patients with the WPW and left-sided bypass tracts, the ablation
catheter during EPS can be positioned within the coronary sinus
and great cardiac veins.

77. References:
▪ Hurst’s The Heart 14th Edition
▪ Braunwalds Heart Disease 12nd edition
▪ Grey’s Anatomy
▪ Grossman’s Textbook of Cardiac Catheterization
▪ Horia Muresian. Coronary arterial anomalies and variations. MAEDICA. A journal of clinical
Medicine,1(1), 2006.
▪ Coronary anomalies: Incidence, Pathophysiology and Clinical Relevance; Angelini P et al;
Circulation. 2002
▪ Atlas of cardiac catheerisation &interventional cardiology; Moscucci et al. 2019
▪ Clinical Methods in Cardiology By Soma Raju, Second Edition, orient longman