This document discusses the anatomy of the coronary circulation as visualized through angiography. It begins by outlining the coronary arterial anatomy, including the typical origins and branches of the right coronary artery and left coronary artery. It then discusses variations that can occur in coronary anatomy and notes the coronary venous anatomy. It concludes by describing the angiographic views used to visualize the coronary arteries.

1. SECOND Step of coronary angiography
Dr. Naresh Sen
Consultant Cardiologist

2. • Anatomy of the coronary circulation
&
Angiographic VISUALIZATION

3. OUTLINE
• Coronary arterial anatomy
• Variations in coronary circulation
• Coronary venous anatomy
• Angiographic views of coronary arteries

4. Coronary arterial anatomy
• 1st anatomical drawings- Leonardo da Vinci
• Oblique inverted crown

5. • The coronary arteries and their major
branches are sub-epicardially located

6. Epicardial Vessel
Subepicardium
Subendocardium
Myocardium
Pericardium
(Epicardium)

7. • LCA ostium ~ 4mm
• RCA ostium~ 3.2mm

8. The LEIDEN convention
• Each artery arises from respective aortic sinuses
- Right coronary sinus(anterior)
- Left coronary sinus(left posterior)
- Non-coronary sinus(right posterior)
1R2LCx
pattern

11. Right coronary artery
~ 9.8cm
1)Conus artery/ Infundibular/ Third coronary/ Adipose
/Arteria of Vieussens
- Separate ostium in 23% - 51%
- Circle of Vieussens

13. Right coronary artery
2) Atrial branches of the RCA
- < 1mm
- SA nodal artery ( Ramus crista terminalis) – 55-65%

14. Right coronary artery
3) Right ventricular branches
- Acute right marginal artery
- Ramus crista supraterminalis (Superior septal artery) –
12 -20% , males

15. Right coronary artery
4) Posterior descending artery
- Dominance
- Posterior septal branches - < 15mm
5) AV nodal artery
- 80 -90%

16. Right coronary artery
6) Postero-lateral branches to the LV
- Inferior wall of the LV

17. Clinical division of the RCA
• Proximal - Ostium to 1st main RV branch
• Mid - 1st RV branch to acute marginal branch
• Distal - acute margin to the crux

18. Left coronary artery
LMCA
- 10-15mm(upto 30mm) length & 3-6mm(upto 10mm
diameter)
- Trifurcates in 1/3rd : Ramus intermedius/ median artery/ left
diagonal artery/straight LV artery
- Rare variations – absent LMCA/ pentafurcation

19. Left anterior descending artery
- ~ 14.7 cm ; Type I (22%) , Type II & Type III
- 2-9 diagonal branches
- 90deg bend after turning around P. conus as it gives off 2nd
diagonal branch
- Right ventricular branches( left conal/pre-infundibular A)
- ~ 10 septal perforating branches (40-80mm X 0.5-1.2mm)
anchors the LAD

20. LAD(contd)
- 1st proximal septal A is prominent (His Bundle and LBB)
- Myocardial bridging – 0.5-1.6% overall (28% in children)
- Rarely dual LADs

21. Clinical division of the LAD
• Proximal - Ostium to 1st major septal perforator
• Mid - 1st perforator to D2 (90 degree angle)
• Distal - D2 to end

22. Left circumflex artery
- ~9.3 cm long ; 1.5 -5mm
- Left atrial branches
- Kugel’s artery (Arteria anastomotica auricularis magna)
- LV branches are called the Obtuse marginal arteries

24. Clinical division of the LCX
• Proximal - Ostium to 1st major obtuse marginal branch
• Mid - OM1 to OM2
• Distal - OM2 to end

25. Coronary segment classification
system
• CASS investigators – 27 segments
• BARI – 29 segments ( ramus intermedius and
3rd diagonal branch)
- Obstructive CAD : > 50% stenosis

26. “Dominance”
• A misnomer
• giving rise to PDA, at least 1 PLV & AV nodal A
(BARI classification)
- 85% right dominant
- 8% left dominant
- 7% co-dominant
(70%/ 10%/ 20% – Hurst’s THE HEART)
• Left dominance is 25-30% in Bi-AoV
Gensini GG. Coronary Arteriography. Mount Kisco,NY: Futura Publishing Co; 1975:260–274.

27. Nodal blood supply
• Studies on nodal blood supply principally by
James (1961) and Hutchinson( 1978)
- James : SA node - RCA 55% & LCA 45%
AV node- RCA 90% & LCA 10%
- Hutchinson : SA node - 65% & 35%
AV node- 80% & 20%
AV node may have dual supply in 2% cases

28. Arterial anastomoses
• Seen at the intracoronary/inter-coronary levels in
abundance– significant in development in
collaterals in CAD
• Most abundant at the septum
• Intracoronary : 1-2cm X 20- 250 micm
• Inter-coronary: 2-3 cm X 20-350 micm

29. Coronary artery variations
• 2 coronary artery system is a recent evolutionary
acquisition
• Fish and amphibia – 1 coronary artery
• Birds – ~ 40% have single coronary arteries.
• 1-5% of those undergoing CAG
Angelini P – Coronary artery anomalies – current clinical issues. Definition, classifications, incidence, clinical relevance and treatment guidelines.
Tex Heart Inst J 2002;29:271-278

30. Coronary artery variations
• Definition of a coronary artery is not based on its origin
and proximal course, but by focusing on its intermediate
and distal segments/ its dependent microvascular bed.
Angelini P – Coronary artery anomalies – current clinical issues. Definition, classifications, incidence, clinical relevance and treatment guidelines. Tex Heart Inst
J 2002;29:271-278

31. • ? Coronary artery Variation vs Anomalies
• A broad spectrum of variations of which some
may cause adverse effects
• Most of the coronary variations may have no
clinical implications as can be proven by
myocardial perfusion studies.
• The regional distribution of a coronary artery,
rather than its absolute origin and
characteristics.

32. A puzzling issue…..
• Proximal course of the LAD may be very
different
• LCx may run over atrial or ventricular surface.
• An RCA that terminates in the AV groove well
before the crux may not always be an
obstruction: 7 – 10% (Grossman)
• Double ostia from the RCS
• All 3 arteries from a single sinus
• One single artery……………..and so on……

33. • The most common coronary variation (Cleveland
Clinic-1,26,000 patients) was separate ostia for LAD &
LCX – 0.41% and 2nd commonest was LCX from
RCS / RCA – 0.37%
• However, in another series of 1950 angiograms
coronary anomalies were seen in 5.6% cases and
split RCA (1.2%) was the commonest.
Angelina P. Coronary artery anomalies. Philadelphia, Lippincott Williams & Wilkins, 1999.

34. • Level of variables
1) Ostium 2) Size 3) Proximal course
4) Mid-course 5) Intra-myocardial ramifications
6) Termination
• MSCT with retrospective ECG gating is now
considered the gold standard for characterization of
coronary anomalies.
• Prompt a search for underlying CHDs
1) Shi H, Aschoff AJ, Brambs HJ. Multislice CT imaging of anomalous coronary arteries. Eur Radiol. 2004;14:2172-2182.
2) Memisoglu E, Hobikoglu G, Tepe MS. Congenital coronary anomalies in adults: Comparison of anatomic course
visualized by catheter angiography and electron beam CT. Catheter Cardiovasc Interv. 2005;66:34-42.

35. Abnormal position of ostia
• Coronary orifice below the cuspal margin:
- 10% RCS
- 15% LCS
• Coronaries above the sinotubular jn ~ 6% - leads to difficult
cannulation, esp RCA with a high anterior ostium.

36. Abnormal number of coronary arteries
• Single coronary artery - 0.024%, usually benign
D/d- 2 separate ostia from same sinus, atresia..
Course is important – in 25% a major branch crosses
the infundibulum.
• 3 coronaries -
1) Separate origin of conus artery from RCS (36- 50%)
2) Absent LMCA with separate ostia for LAD & LCX
• 4 coronaries - case reports
• Dual LAD- 0.13 -1% (Morettin ,1976)

37. Absent LMCA
• ~0.4%
- 1 ostia at the LCS/ 2 ostia in LCS/ 1 ostia in LCS & other RCS
- Increased incidence of Left dominance
- 6% incidence of bridging
- Not usually associated with CHDs
- Similar incidence of atherosclerosis
- Difficulty in selective cannulation
Topaz et al. Absent left main coronary artery: angiographic findings in 83 patients with separate ostia of the
left anterior descending and circumflex arteries at the left aortic sinus.
Am Heart J.1991 Aug;122(2):447-52.

38. Shepherd’s-crook RCA
• ~5%
• Acute superiorly angled take-off of the RCA
from the aorta.
• Difficult RCA lesion angioplasty
Ethan Halpern. Cardiac CT . Functional anatomy.

39. Dual LAD (Duplication)
• ~0.13 - 1% of normal hearts
• Proximal LAD (LAD proper) bifurcates early into a
short and long LAD
-Type I : Short LAD in AIVS, Long LAD on prox AIVS, LV side, distal AIVS
-Type II : Short LAD in AIVS, Long LAD on prox AIVS, RV side, distal AIVS
-Type III: Short LAD in AIVS, Long LAD intra-myocardially in septum
-Type IV: Very short LAD proper and short LAD, Long LAD from RCA
Spindola-Franco H et al. Dual left anterior descending coronary artery: angiographic description of Important variants
and surgical implications. Am Heart J 1983:105;445–55.

40. Coronary artery Ectasia
• 1 - 5% in angiographic series, more in males
• 20- 30 % are congenital
• Dialatation of a segment to at least 1.5times of the
adjacent normal coronary artery.

41. Coronary venous anatomy
• Targeted drug delivery
• Retrograde cardioplegia administration
• Potential conduit to bypass cor. artery stenosis
• Stem cell delivery to the infarcted region
• Access to LA & LV myocardium for arrythmia mapping
& ablation
• LV epicardial pacing in CRT

42. Coronary venous anatomy

43. THEBESIAN veins – Venae cordis minimae

44. Conventional coronary venous
nomenclature
• Coronary sinus - Thebasian valve
• Anterior IV vein(Great cardiac vein) - Vieussens valves
- Left marginal vein of LV
- Postero-lateral LV vein
• Middle cardiac vein
• Small cardiac veins
• SEGMENTAL CLASSIFICATION

45. Segmental venous classification
• Thus 9 LV venous segments are derived which when added with the
conventional classification gives the best comprehensive information to place
the epicardial LV leads for CRT purposes

46. Retrograde coronary venography

47. MDCT angiogram delineating coronary
veins along with arteries

48. Coronary Angiographic Views
• Cardiac Cath 1st by Werner Forssman in 1929
• 1st contrast angiography by Chavez in 1947
• CART 1st performed by F. Mason Sones in 1958
• a high-resolution image-intensifier television system with digital
cineangiographic capabilities.
- Radiograph tube below and Image intensifier above
(Flouroscopic imaging system with C-arm)
- Physiologic monitoring system, sterile supplies, resuscitation
equipment, Contrast injector (3-8ml/sec) and contrast media

49. • Information from a CAG:
CAG helps visualization of the major epicardial arteries up
to their 2nd and 3rd order branches
- Coronary anatomy
- Characteristics and distribution of coronary stenosis
- Distal vessel size
- Intracoronary thrombus
- Index of coronary flow
- Mass of myocardium served
- Collateral vasculature
Optimal injection rate: 7ml (2.1ml/s) for LCA and 4.8ml (1.7ml/s) for RCA

50. Pitfalls of CAG –
A Lumenogram

51. Interpretation of the significance of a
lumenogram
• Multiple projections from different angles, preferably
orthogonal
• Knowledge of the normal calibre of major coronaries:
LMCA: 4.5 ± 0.5 mm
LAD: 3.7 ± 0.4 mm
LCX : 3.5 ± 0.5 mm ( 4.2 mm if dominant)
RCA: 3.9 ± 0.6 mm ( 2.8 mm if non-dominant)
• IVUS
• Functional studies : FFR

52. Mistakes in CAG interpretation
• Inadequate number of projections used
• Improper/inadequate contrast injection
• Super-selective injection
• Catheter induced vasospasm
• Coronary artery variations
• Myocardial bridges
• Total ostial occlusions
• Wire induced spasm (ACCORDION EFFECT)

54. • LAO and RAO views help furnish the true PA and
lateral views of the heart
D/A s - foreshortening
- superimposition
• Cranial view: Image-intensifier tilted towards head
• Caudal view: Image-intensifier tilted towards the feet
-however the optimal angiographic view varies with
coronary anatomy, body habitus and location of lesion
Angiographic projections

55. Angiographic projections
Kern MJ. Cardiac Catheterization Handbook. 5th edition,2011.

56. RAO and LAO projections

57. Optimal angiographic views for coronary segments
Carlo Di Mario, Nilesh Sutaria. CORONARY ANGIOGRAPHY IN THE ANGIOPLASTY ERA: PROJECTIONS WITH A MEANING
Heart 2005;91:968–976.

58. RAO- LCA

59. RAO- RCA

60. Optimal angiographic views for coronary segments
Carlo Di Mario, Nilesh Sutaria. CORONARY ANGIOGRAPHY IN THE ANGIOPLASTY ERA: PROJECTIONS WITH A MEANING
Heart 2005;91:968–976.

61. Shallow RAO cranial - LCA

62. AP cranial - LCA

63. RAO cranial - RCA

64. Optimal angiographic views for coronary segments
Carlo Di Mario, Nilesh Sutaria.CORONARY ANGIOGRAPHY IN THE ANGIOPLASTY ERA: PROJECTIONS WITH A MEANING
Heart 2005;91:968–976.

65. RAO caudal - LCA

66. Optimal angiographic views for coronary segments
Carlo Di Mario, Nilesh Sutaria.CORONARY ANGIOGRAPHY IN THE ANGIOPLASTY ERA: PROJECTIONS WITH A MEANING
Heart 2005;91:968–976.

67. AP (Shallow RAO) caudal- LCA

68. Optimal angiographic views for coronary segments
Carlo Di Mario, Nilesh Sutaria.CORONARY ANGIOGRAPHY IN THE ANGIOPLASTY ERA: PROJECTIONS WITH A MEANING
Heart 2005;91:968–976.

69. LAO - LCA

70. LAO - RCA

71. Optimal angiographic views for coronary segments
Carlo Di Mario, Nilesh Sutaria. CORONARY ANGIOGRAPHY IN THE ANGIOPLASTY ERA: PROJECTIONS WITH A MEANING
Heart 2005;91:968–976.

72. LAO cranial - LCA

73. LAO cranial - RCA

74. Optimal angiographic views for coronary segments
Carlo Di Mario, Nilesh Sutaria.CORONARY ANGIOGRAPHY IN THE ANGIOPLASTY ERA: PROJECTIONS WITH A MEANING
Heart 2005;91:968–976.

75. LAO caudal (Spider view) - LCA

76. Optimal angiographic views for coronary segments
Carlo Di Mario, Nilesh Sutaria.CORONARY ANGIOGRAPHY IN THE ANGIOPLASTY ERA: PROJECTIONS WITH A MEANING
Heart 2005;91:968–976.

77. Lateral view
•Mid & distal LAD
•Proximal LCX
•Mid RCA
•LIMA graft to LAD

78. Optimal angiographic views for coronary segments
Carlo Di Mario, Nilesh Sutaria. CORONARY ANGIOGRAPHY IN THE ANGIOPLASTY ERA: PROJECTIONS WITH A MEANING
Heart 2005;91:968–976.
There is no single magical projection that can be
applied uniformly to all patients for visualizing
a particular coronary atery

79. Panoramic coronary angiography
GIORGIO TOMMASINI et al. Panoramic Coronary Angiography. JACC 31(4),March 15, 1998:871–7

80. References
• Hurst’s The Heart 13th Edition
• Braunwalds Heart Disease 9th edition
• Grey’s Anatomy
• Kern’s Handbook of Interventional Catheterization
• Kjell C Nikus. Coronary angiography.
• Grossman’s Textbook of Cardiac Catheterization
• Carlo Di Mario, Nilesh Sutaria. CORONARY ANGIOGRAPHY IN THE ANGIOPLASTY
ERA: PROJECTIONS WITH A MEANING Heart 2005;91:968–976
• David M Fiss. Normal coronary anatomy and anatomic variations. Applied
Radiology, Jan 2007.
• Horia Muresian. Coronary arterial anomalies and variations. MAEDICA. A journal
of clinical Medicine,1(1), 2006.
• Singh et al. The coronary venous anatomy. A segmental approach to aid CRT
2005, 46(1), 68-74.
• Shilpa Bhimali et al. A STUDY OF VARIATIONS IN CORONARY ARTERIAL SYSTEM IN
CADAVERIC HUMAN HEART. World Journal of Science and Technology 2011, 1(5):
30-35 ISSN: 2231 – 2587.

81. Thank you