Aortic Valve

The normal aortic valve consists of three equally sized valve cusps: the right coronary cusp (R), the left coronary cusp (L) and the non-coronary cusp (N). With 2D echocardiography, the valve can be assessed in the PLAX, where the RCC and the NCC are visible. In a normal tricuspid aortic valve, the closure line is (between RCC and NCC) usually in the centre of the aortic valve ring. However, in the PSAXao the three cusps in systole almost form a circle and during diastole the closure lines resemble an inverted Mercedes-Benz logo. Assessing the number of cusps is best done during systole, because the valve is open. When it’s closed, a so called raphe can be mistaken for a closing line. Today beautiful images of the aortic valve can be arrived with 3D echocardiography.

 

3D-image of an aortic valve with TOE

 


Different shapes of the aortic valve

 

Unicuspid

Bicuspid

Tricuspid

Quadricuspid

Quantification of aortic valve regurgitation
Parameter Mild Moderate Severe
Jet/LVOT (%) <25 25-65 >65
PHT (m/s) >500 500-300 <300
Vena contracta (mm) <3 3-6 >6

 

Causes of aortic valve regurgitation
Congenital Bicuspid aortic valve.
Damage to the aortic valve Rheumatic fever.
Degeneracy.
Endocarditis.
Syphilis.
Trauma.
Metabolic diseases such as mucopolysaccharidosis.
Aortic dilation Connective tissue disease, such as Marfan's syndrome, Ehlers-Danlos' syndrome.
Aneurysm by inflammation, such as syphilis, vasculitis.
Aneurysm in aortic atherosclerosis.
Aortic dissection.

 

Severe AR

 

Quantification of aortic valve stensis
Parameter Mild Moderate  Severe
PG max (mmHg) 15-40 40-70 70-100 
PG mean (mmHg) <20 20-40 >40
AVA (cm²) >1.5 1.5-1.0 <1.0
Dimensionless index > 0.50 0.25-0.50 <0.25
Vmax (m/s) <3 3-4 >4
AVA BSAindex (cm²/m²) >0.85 0.85-0.60 <0.60

 

Causes of aortic valve stenosis
Supravalvular: (usual congenital) Valvular: Subvalvular:
A pleat or membrane of the aorta Congenital form; often the aortic valve is bicuspid Congenital malformation: a membrane in LVOT
Narrowing of the aorta By rheumatic fever Hypertrophic obstructive cardiomyopathy, an autosomal dominant hereditary disorder
Williams Syndrome degenerative form Subvalvular aortic stenosis has also been described as a result of any of the lysosomal storage diseases

 

Calcified right coronairy cusp

Bicuspid aortic valve (BAV) is the most common congenital cardiac valve abnormality. In BAV two valve leaflets are fused from birth. BAV occurs in 1-2% of the population and twice as often in men as in women. BAV can be hereditary in which both familial clustering and isolated valve defects are documented. The incidence of bicuspid aortic valve may reach up to 10% in certain families. A BAV is often associated with other congenital heart defects such as coarctation of the aorta. Usually there is a fusion between the LCC and RCC (70%). Initially, the bicuspid aortic valve will not cause problems. Later in life, the valve has an increase risk of calcified deformation which can lead to stenosis and/or regurgitation through malcoaptation of the affected cusps. In BAV cusps are of unequal size and usually show a raphe at the largest cusp. A raphe is a fibrotic ledge that connects the edges of congenital fused cusps and does not consist of valve tissue.

 

 

 

 

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