1. Anatomy of the coronary circulation & Angiographic VISUALIZATION
Dr Sandeep Mohanan
Department of Cardiology
Calicut Medical College
1/10/12

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

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

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

5. Pericardium (Epicardium)
Epicardial Vessel
Subepicardium
Myocardium
Subendocardium

6. LCA ostium ~ 4mm
RCA ostium~ 3.2mm

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

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

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

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

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

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

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

17. 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

18. Left anterior descending artery
- ~ cm ; Type I (22%) , Type II & Type III
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 mm) anchors the LAD
LAD supplies 45-55% of LV

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

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

21. Left circumflex artery
~9.3 cm long ; mm
Left atrial branches
Kugel’s artery (Arteria anastomotica auricularis magna)
LV branches are called the Obtuse marginal arteries
LCx supplies 15-25% of LV (40-50% in dominant LV)

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

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

25. Prognostication scores
Califf scoring system
Gensini scoring system
Candell-Riera scoring system
CASS investigators: - no. of vessels
- no. of proximal segments
- Global LV function

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 : cm X micm
Inter-coronary: cm X 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:

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:

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. Level of variables
1) Ostium ) Size ) Proximal course
4) Mid-course 5) Intramyocardial ramifications 6) Termination
Anomalies without a shunt:
1. Abnormal number : 1/ 3/ 4 ostia
2. Anomalous origin: a) Outside SOV
b) Independent origin from same sinus
c) Opposite sinus
d) Other artery
3. Myocardial bridge
4. Segmental stenosis/hypoplasia
Anomalies with shunt:
1) Fistula ) APOCA
C. Aneurysms

33. 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……

34. 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.
127,000 patients (Grossman)
Angelina P. Coronary artery anomalies. Philadelphia, Lippincott Williams & Wilkins, 1999.

35. 1) Ostium 2) Size 3) Proximal course
Level of variables
1) Ostium ) Size ) 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:
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.

36. 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.

37. Abnormal number of coronary arteries
Single coronary artery %, 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 % (Morettin ,1976)

38. 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):

39. 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.

40. Dual LAD (Duplication)
~ % 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.

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

42. 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

43. Coronary venous anatomy

44. THEBESIAN veins – Venae cordis minimae

45. 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
The highly variable existence of the conventional veins calls for segmental classification (ant, lat, post, base, mid and apex -9 segments of the LV) of coronay veins for better epicardial localization of veins for interventional electrophiography purposes.

46. 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

47. Retrograde coronary venography
Lateral LV wall venous branches can be profiled by individualizing the different radiological views- considering the anterior IV vein and middle cardiac vein as reference points.

48. MDCT angiogram delineating coronary veins along with arteries
Before venogram for better characterisation of coronary vein variations. However additional 60ml contrast and 9-11mSv exposure.

49. 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
Xray generator, Xray tube , Image intensifier and detector, digital angio imaging.
A higher angulation increases the radiation scatter.
Fluoroscopy has only 1/5th rad exposure of cine angiography
NCRPM guideline: not >3 rem per 3months.. Advised safe limit is 100mrem/week for cath lab personnel.
Skin and thyroid- 15rem/year, gonads, eyes, bonemarrow- 5rem/yr
Cxray= 3 -5 mRoentgen ( 1 R = 1 rad for skin, 1R= 4rad for bone due to more absorption)
R= radiation exposure, Rad = radiation absorptioon)
Rem= radiation equivalent dose in man. 1 rem= 1rad.
1SV= 1J/kg=1Gy
1gy=100rad
1Sv= 100rem
1mrem=10micSv

50. 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

51. Pitfalls of CAG – A Lumenogram

52. 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

53. 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)
Accordion effect: A mechanical alteration in the geometry and curvature of the vessel due to straightening and shortening of the artery due to wire advancement.

55. Angiographic projections
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

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

57. RAO and LAO projections

58. 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.

59. RAO- LCA
When the LMCA, LAD, LCX have an initial leftward course the long axis of these arterial segments are projected away frm the image intensifier and prevent optimal visualisation in the RAO view.

60. RAO- RCA

61. 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.

62. Shallow RAO cranial - LCA

63. AP cranial - LCA

64. RAO cranial - RCA

65. 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.

66. RAO caudal - LCA

67. 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.

68. AP (Shallow RAO) caudal- LCA

69. 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.

70. LAO - LCA

71. LAO - RCA

72. 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.

73. LAO cranial - LCA
Some overlap with LCX can be overcome by more 60 degree LAO tilt.
However when the proximal LCA is superiorly directed it is not an optimal view- use LAO caudal

74. LAO cranial - RCA

75. 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.

76. LAO caudal (Spider view) - LCA
Enhanced by maximal expiration as the heart becomes more horizontal

77. 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.

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

79. Optimal angiographic views for coronary segments
There is no single magical projection that can be
applied uniformly to all patients for visualizing
a particular coronary atery
According to Grossman: For LCA – RAO caudal and LAO caudal for LMCA and proc LAD in orthogonal & RAO cranial and LAO cranial for mid and distal LAD in orthogonal
For RCA: LAO for proximal RCA and RAO cranial for distal, PDA, PLV and Lateral view for mid
Carlo Di Mario, Nilesh Sutaria. CORONARY ANGIOGRAPHY IN THE ANGIOPLASTY ERA: PROJECTIONS WITH A MEANING Heart 2005;91:968–976.

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

81. 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),
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): ISSN: 2231 – 2587.

82. Thank you