Aortic valve

Anatomy

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.

Cross section of the heart valves

3D-image of a tricuspid aortic valve (TEE)

2D-image of a tricuspid aortic valve (TTE).

Regurgutation

Quantification of aortic valve regurgitation

ParameterMildModerateSevere
Jet/LVOT (%)<2525-65>65
PHT (m/s)>500500-300<300
Vena contracta (mm)<33-6>6

Echocardiographic criteria for the definition of severe aortic valve regurgitation: an integrative approuch

QualitativeSemiquantitativeQuantative
Valve morphology: Abnormal/flail/large coaptation defectVena contracta width: >6 mmEROA: ≥30 mm²
Colour flow regurgitant jet: Large in central jets, variable in eccentric jets *Pressure half-time: <200 ms ** Regugitant volume: ≥60 mL/beat
Dense CW signal of regurgitant jetEnlargement of LV
Holodiastolic flow reversal in descending arota (EDV >20 cm/s)
* At Nyquist limit of 50-60 cm/s.
** Pressure half-time is shortened with increasing LV diastolic pressure, vasodilator therapy, and in patients with a dilated compliant aorta, or lengthened in chronic aortic regurgitation.

Causes of aortic valve regurgitation

Causes
CongenitalBicuspid aortic valve.
Damage to the aortic valveRheumatic fever.
Degeneracy.
Endocarditis.
Syphilis.
Trauma.
Metabolic diseases such as mucopolysaccharidosis.
Aortic dilationConnective tissue disease, such as Marfan's syndrome, Ehlers-Danlos' syndrome.
Aneurysm by inflammation, such as syphilis, vasculitis.
Aneurysm in aortic atherosclerosis.
Aortic dissection.

European Journal of Echocardiography (2010) 11, 223?244

Stenosis

Quantification of aortic valve stensis

ParameterMildModerate Severe
PG max (mmHg)15-4040-7070-100
PG mean (mmHg)<2020-40>40
Acceleration time (ms)>100
Vmax (m/s)<33-4>4
AVA (cm²)>1.51.5-1.0<1.0
AVA BSAindex (cm²/m²)>0.850.85-0.60<0.60
Dimensionless index> 0.500.25-0.50<0.25

Causes of aortic valve stenosis

Supravalvular
ValvularSubvalvular
A pleat or membrane of the aortaCongenital form; often the aortic valve is bicuspidCongenital malformation: a membrane in LVOT
Narrowing of the aortaBy rheumatic feverHypertrophic obstructive cardiomyopathy, an autosomal dominant hereditary disorder
Williams Syndromedegenerative formSubvalvular aortic stenosis has also been described as a result of any of the lysosomal storage diseases

European Heart Journal (2017) 00, 1?53

Bicuspid

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.

Variations of bicuspid aortic valve

Bicuspid type 2

J Thorac Cardiovasc Surg. 2007 May;133(5):1226-33.