8. • The functionality of the mitral valve as a
‘complex’ is very essential for the smooth
cardiac physiology
• A glitch in any one of the 7 components of the
‘complex’ will impair the mitral anatomy,
hence the physiology
12. Leaflet features
• Anterior leaflet – 1/3rd of annular
circumference
• Posterior leaflet – 2/3rd of annular
circumference
• Normal mitral valve area(MVA) – 4.0-5.0sq.cm
13.
14. Leaflet Histology
• Leaflets are composed of a fibrous skeleton
with an endocardial surface.
• The atrial layer has a smooth endocardial cell
layer.
• On the anterior leaflet, this smooth
endocardial layer is also present on the
ventricular side.
15. • Heart Valves are essentially generated from
the double-sided fusion of the Tunica Intima
emanating from the cardiac wall.
• The endothelium is continuous with that of
the cardiac wall while the normally delicate
collagenous layer which invests the
endothelium toughens and becomes highly
fibrous as it transitions into the heart valve.
• Consequently, heart valves are highly thin yet
extremely robust, allowing for hundreds of
millions of open-close events during the
course of a lifetime.
16. Zone of Coaptation
• On the atrial surface of the leaflets exist two
zones, one peripheral smooth or body zone and
one central rough or coaptation zone, which is
irregular and thicker due to the numerous
chordae attached to its ventricular side.
• The gently curved coaptation line between the
two leaflets evident from an atrial view separates
these two areas. The rough zone represents the
coaptation surface of the valve.
• The coaptation zone of the valve is critical to
valve competency, and the depth and length of
coaptation is now often viewed as an important
assessment of mitral valve function.
19. Features
• The anterior portion of the mitral annulus is
attached to the fibrous trigones and is generally
more developed than the posterior annulus.
• The right fibrous trigone is a dense junctional
area between the mitral, tricuspid, non-coronary
cusp of the aortic annuli and the membranous
septum.
• The left fibrous trigone is situated at the junction
of both left fibrous borders of the aortic and the
mitral valve.
20. • The mitral annulus is less well developed at
the insertion site of the posterior leaflet.
• This segment is not attached to any fibrous
structures, and the fibrous skeleton in this
region is discontinuous.
• This posterior portion of the annulus is prone
to increase its circumference in the setting of
mitral regurgitation in association with left
atrial or left ventricle dilation; correction of
the annular dimension to normal is therefore
an essential part of reconstructive
degenerative mitral valve surgery.
21. • The mitral annulus is saddle shaped, and
during systole the commissural areas move
apically while annular contraction also
narrows the circumference.
• Both processes aid in achieving leaflet
coaptation, and may be affected by processes
such as annular dilatation and calcification
24. Types of chordae
Classified based on the site of
insertion on leaflets:
Primary/ Marginal chordae –
Insert at the free margin of
leaflets
Secondary/ Intermediate
chordae – Insert midway
between base and free margin
Tertiary/ Basal chordae – Insert
into the base of leaflets
28. • APM has dual blood supply – OM of LCX + D1
of LAD
• PPM has single blood supply – Last OM/ RCA
depending on the coronary dominance
• So, PPM is mostly involved in ischaemic MR
47. Alfieri stitch
• A suture is placed between A2
and P2
• Produces 2 mitral orifices
•May cause mild mitral stenosis
• Useful in FMR due to annular
dilatation
70. Tricuspid valve as a ‘bicuspid’ valve
• Contentious school of thought
• Septal leaflet and mural leaflet(anterior and
posterior combined)
• Due to RV contraction, mural leaflet has clefts-
ranging from 2 to 6
75. Leaflets
• The anterior leaflet is the most mobile & the
largest leaflet
• The septal leaflet is the least mobile leaflet –
helps to maintain an elliptical configuration of the
TV and hence prevent TR
• TV is not designed to close a circular orifice
• Accessory cusps – 2-8 cusps are present
sometimes
80. • The location of the APM is important
• Lateral tethering angle – angle between leaflets
and the chordae of APM at mid-end systole is
90deg – Important for optimal leaflet coaptation
• Septal papillary muscle ‘complex’ is called
Lancisi’s muscle – anatomical significance
• Moderator band – contains RBB, attached to APM
82. RV wall
• Culprit in functional TR – commonest cause of
TR
• RV dilatation secondary to various causes
leads to TV annular dilatation functional TR
83. This is important because only the anterior and
posterior portions of the annulus need plasty,
septal portion does not
86. TAPSE – Tricuspid Annular Plane
Systolic Excursion
TAPSE represents the distance of systolic
excursion of the RV annular plane towards the
apex.
87.
88. Vena contracta
• Narrowest portion of the TR jet which has the
maximum velocity
• Helps to identify Severe TR
• Diameter of vena contracta >= 7mm is an
indication of Severe TR
102. Tricuspid valve replacement
• Usually avoided, repair is preferred
• If at all done, Bioprosthetic valve is preferred
• Risk of thrombosis if mechanical valve is used
• Tricuspid excision without replacement is an
option (IV drug abusers, No PHTN)
104. Take home messages
• Mitral valve is a complex – works in synchrony
• Very important to respect the relations of the
mitral and tricuspid valve
• Tricuspid valve – A ‘fingerprint’
• Tricuspid repair better than replacement in terms
of outcome
• Repair/ Replacement requires a thorough
understanding of the anatomy
105. References
• Wilcox’s Surgical Anatomy of the Heart 4th ed.
• Heart Valve Surgery – An illustrative Guide,
Jan Doiminic & Pavel Zacek
• www.mitralvalverepair.org
• Google images
