The aortic valve has three leaflets (cusps) and is located between the left ventricle and the ascending aorta. It has important relationships with surrounding structures like the mitral valve, ventricular septum, and conduction bundles. The leaflets are attached to fibrous structures like the annulus, sinuses of Valsalva, and sinotubular junction. On echocardiogram, the aortic valve can be seen opening and closing from the parasternal long and short axis views. The document provides details on the anatomy, embryology, histology, and imaging of the aortic valve.

1. Aortic valve anatomy

2. Headings to cover
History
Embryology
Histology
Structure and components of Ao valve
Basic arrangement
Relationship with other important structures
Aortic valve in ECHO

3. History
*Leanardo Da Vinci
1512-13
*Description of
LVOT, aortic valve
with sinus.

5. *description of
eddy currents as-
“the effect of this revolution of the
blood is to shut again the open valve of
the heart making by its primary
reflected motion a perfect closure”
(Quadr. Anat. IV, fol. ll

6. History
Andreas Vesalius (1514-1564):
description of aortic valve.

7. Embryology
Marc Sylva et al, Development of the Human Heart, american journal of medical genetics,2013

8. Histology
• Dense collagenous layer(43-
55%)
• Central core of loose
connective tissue
• Elastin layer below the inflow
surface(11%)
• Valvular endothelial cells
(VECs)
• Valvular interstitial cells
(VICs)[most abundant cells]
• Extracellular matrix.

9. Structure and macroscopic anatomy of
the aortic valve
Components
• Annulus
• Leaflets
• Commissures
• Interleaflet triangles
• Sinus of Valsalva
• Sino tubular junction

10. Annulus
• 3 circular rings
• Word annulus is controversial.
• Constitute a crown-like circlet rather
than a true ring- 3 pronged

11. Annulus
Anatomic ventriculo
arterial junction
Basal ring
• Basal ring: joining nadirs of leaflets (ECHO)
• Anatomic ventriculo arterial junction:
ventricular myocardium terminates and
aortic sleeve starts
• STJ: highest point of leaflet attachment

13. Leaflets
• Three leaflets
• crimped surface facing the aorta ,smoother
surface facing the ventricle.
• thicker towards its free margin

14. Leaflets
• Components:
- Lunulae(zone of apposition)
- Nodule of Arantius
- Body(crimpled facing the aorta, smoother
facing the ventricle)
- Hinge

16. Lunule
• Free edge-Meets the adjacent leaflets during
valvular closure.
• In closed position, the inferior margin of the
lunulaes meet together
• Fenestrations may be present(usually spares
inferior margin-retaining competence)

17. Nodule of Arantius
• Midportion of the lunulae
• Ventricular surface is thickened
• Contains predominantly elastin
• Triangular In shape

18. Microscopic anatomy
• Lamina fibrosa
(mainly collagen some elastin) Lamina arterialis
• Lamina spongiosa
• Lamina ventricularis
(mainly elastin)- thicker at lunula and node
-Core of the leaflet  continuous with the fibrous
wall of the aortic sleeve at the hingelines (fibrous
tissues thickened)

19. Microscopic anatomy

20. Leaflets
• Total area of leaflets -40% greater than that of
the aortic root.( Davies et al)
• Three leaflets are not perfectly equal in
dimensions.(Roberts et al)

21. Leaflet measurements
x
3x
2x

22. Commissures
• Highest point of valvular closure line
• Till the level of STJ

23. Interleaflet fibrous triangles

24. Interleaflet fibrous triangles
• 3 triangular
extensions of the
left ventricular
outflow tract.
• Reach till STJ
• Thinned fibrous
walls of the aorta
• Potential
communication
with the
pericardial space

25. Sinuses of Valsalva
• Named after Antonio Valsalva
• From leaflet atachment till STJ
• Vortices reduce stress on leaflets.
• Support coronary flow
• Prevents an increase in the pressure decrease
across the valve

27. Production of vortices and mechanism of closure of aortic valves(schematic) and 4D CT
images.

28. STJ
• Superior border of the
sinuses
• Also known as the
supra-aortic ridge.
• Outside- tubular aorta
joining sinus
• Inside- slightly raised
ridge of thickened
aortic wall.
• Not perfectly circular.
mildly trefoil or
scalloped outline

29. Basic arrangement
• Wedged between 2
AV valves.
• Centre piece of
cardiac skeleton
• 30º in horizontal, 45º
in median plane.

30. Relationship with mitral valve

31. Relationship with mitral valve
• Circular left ventricle.
• Mitral valve and aortic valve in
fibrous continuity.
• Thickened areas of fibrous
continuity form the left and
right fibrous trigones
• The interleaflet triangle between
the NC and LC leaflet- part of
fibrous continuity.

33. Relation with ventricular septum
• Interleaflet between RC & NC leaflets is confluent with the
membranous septum.
• Membranous septum and the right fibrous trigone form- central
fibrous body.

34. Aortic valve and conduction bundle

36. Overall relationships of aortic root

39. Echo- PLAX view

41. ECHO- PSAX

42. Thank you