The document discusses the arterial blood supply and venous drainage of the heart. It notes that the heart receives its blood supply from two coronary arteries - the right and left coronary arteries. These arteries branch further to supply different regions of the heart. The venous drainage occurs primarily via the coronary sinus, which drains into the right atrium. A few small veins also drain directly into the right atrium. The document outlines the branches and territories supplied by the right and left coronary arteries in detail.

1. An Introduction to Cardiology
Nikhil Vaishnav, Clinical Coordinator
Department of Paramedical & Health Science

2. Blood supply of the heart
CHAPTER-6

4. Arterial blood supply of heart
Arterial blood supply of heart
Heart is supplied by
coronary arteries.
 Anatomically coronary
arteries are not end
arteries, but functionally
they behave like end
arteries.
Coronary is vasa vasorum
of ascending aorta.

5. Arterial blood supply of heart
 Coronary arteries are
vasa vasorum arising from
aortic sinuses of Valsalva
of Ascending aorta
 Right coronary artery
arises from right aortic
sinuses
 Left coronary artery
arises from left aortic
sinuses.

6. Right coronary artery
Coronary arteries of heart
 Right coronary artery
Arises from anterior
aortic sinus of ascending
aorta.
 Right coronary artery is
smaller than the left
coronary

7. RCA origin from aortic sinus

8. Courses of Right coronary artery
 Passes forwards & to right between pulmonary trunk and right auricle.
 Passes downwards to right in anterior atrioventricular groove and winds
round the inferior border to reach the diaphragmatic surface of heart.
 Passes upwards to left in posterior part of atrioventricular groove & reach
crux of heart .
 Ends by anastomosing with circumflex branch of left coronary artery.

9. Branches of right coronary artery
Right coronary artery branches
Small branches
 Nodal in 60%
cases.
 Right atrial
 Infundibular
 Terminal
branch
 Right
ventricular
branch
 Conus branch

10. Branches of right coronary artery
Branches of RCA
Large branches
Marginal.
 Posterior
interventricular.

11. Area of distribution
1. Right atrium
2. Greater part of right ventricle
3. Small part of left ventricle adjoining inter ventricular groove
4. Posterior part of interventricular septum
5. Conducting system of heart in 40%

12. Coronary arteries area of distribution

13. Left coronary artery
Left coronary artery
Arises from
left posterior
aortic sinus of
ascending aorta
 Left coronary
artery is larger
than the right
coronary

14. Area of distribution
• Passes forwards & to left between pulmonary trunk and left auricle.
Divides into anterior interventricular artery & circumflex artery.
• Anterior interventricular artery – continuation of LCA descends in the
anterior interventricular groove up to the apex.
•Circumflex artery – passes to left in the left atrio ventricular groove.
Winds round the left border of heart & occupies posterior part atrio
ventricular groove – anatomises with RCA (crux)

15. Branches of left coronary artery
Branches of LCA
1. Anterior
interventricular
artery (left anterior
descending(LAD):
Also known as
widow maker artery
2. Circumflex artery

16. Branches of Circumflex artery
• Atrial & ventricular rami-LA & RA
• Sino-atrial nodal artery[in 35% people]
• Left marginal artery
• Circumflex artery- contd.. as Posterior interventricular artery [in 10%
people] .
• Atrial branch- communicate with similar branch of RCA (Kugels artery).

17. Branches of Left anterior descending (LAD)
LAD branches
 Conal branch
 Anterior ventricular
branches: right and left
 Interventricular septal
branches: (anterior,
inferior) .

18. LAD branches

19. LAD branches

20. LAD branches

21. Area of distribution of LCA
1. Left atrium
2. Major part of left ventricle adjoining posterior interventricular groove
3. Small part of right ventricle adjoining anterior interventricular groove
4. Anterior part of interventricular septum
5. A part of left branch of AV bundle

22. Cardiac dominance
 Mostly the right coronary artery gives posterior interventricular artery
branch . Such hearts are right dominant heart.
 In about 10% of hearts, the right coronary is rather small and is not able to
give the posterior interventricular branch. In these cases the circumflex
artery(LCA) provides the posterior interventricular branch ,Such cases are
called left dominant.
 70% cases post IV is a branch of RCA (Right coronary dominance)

23. Coronary artery that gives post IV branch is supposed to be dominant. Thus
the artery giving the posterior interventricular branch is the dominant artery.
 In Left dominance heart a block in LCA affect entire Left ventricle and IV
septum, while in Right or balanced dominance a block in RCA at least spares
part (2/3) of septum and left ventricle.

24. Coronary dominance

25. Coronary dominance

26. Venous drainage of the heart
 In heart most of the veins drain into the coronary sinus which opens in
right atrium.
 The anterior cardiac veins and the venae cordis minimi open directly into
the right atrium.
 The coronary sinus is the largest vein of the heart. It is situated in the left
posterior coronary Sulcus .It is about 3 cm long. Opens into Right atrium
b/between IVC and Tricuspid opening guarded by incomplete semicircular
“Thebesian valve”.
All veins of coronary sinus have valves except oblique Vein of left atrium

27. Venous drainage of heart

28. Tributaries of coronary sinus
1. Great Cardiac vein
2. Middle cardiac vein
3. Small cardiac vein
4. The posterior vein of the left ventricle
5. The oblique vein of the left atrium
6. The right marginal vein

29. Coronary sinus

30. Tributaries of coronary sinus
 Great Cardiac vein begins first the anterior interventricular artery and
then the left coronary artery. It terminates at the left end of coronary
sinus.
 Middle cardiac vein accompanies the posterior interventricular artery
and joins the middle part of coronary sinus.
 The small cardiac vein accompanies the RCA in the right posterior
coronary Sulcus. It joins the right end of the coronary sinus. The right
marginal vein may drain into the small cardiac vein .

31.  The posterior vein of the left ventricle runs on the diaphragmatic surface
of the left ventricle and it ends in the coronary sinus.
 The oblique vein of the left atrium of Marshall is a small vein running on
the posterior surface of the left atrium .It terminates in the left end of the
coronary sinus.
The right marginal vein accompanies the marginal branch of the right
coronary artery. It may either drain into the small cardiac vein or may open
directly into the right atrium.

32. Coronary sinus

33. Venous drainage of heart

34. Venous drainage of heart

35. Venous drainage of heart

36. Veins emptying directly into the right atrium
 Anterior cardiac veins are three or four small veins that drain the
infundibulum of right ventricle. These open directly into the right atrium
through its anterior wall.
 Venae cordis minimi or Thebesian veins are numerous small valve less
veins present in all four chambers of the heart. These are more on the right
side of the heart rather than left.

37. Anterior cardiac vein

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