EchocardiographyExercise StressMiscEchocardiography
Aortic Valve Velocity RatioLV EF (Modified Quinones Equation)Myocardial Performance Index (RV)
AVA (Continuity Equation VTI)LV EF (Simplified Quinones Equation)PCWP by E/Ea (Nagueh Formula)
AVA (Continuity Equation VMax)LV Fractional ShorteningPISA (Mitral regurgitation)
dP/dt (LV contractility)LV Mass and LV Mass IndexPISA (Mitral stenosis)
dP/dt (RV contractility)Mitral valve area (PHT)Qp/Qs
Left atrial pressure (MR)Mitral Valvuloplasty Score (MGH)RVSP (TR)
LA Volume (Biplane Method)Modified Bernoulli EquationStroke Volume, Cardiac Output
LV EF (Dumesnil Method)Myocardial Performance Index (LV)
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Aortic Valve Area (Continuity Equation using VMax)

Calculation


V1 m/s Height
V2 m/s Weight
LVOT mm


AVA cm2
AVA Index cm2/m2
Calculate

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Information

Definition of Aortic Stenosis Severity

AVA (cm2) AVAI (cm2/m2)
Normal 3.0-4.0
Mild >1.5 >0.85
Moderate 1.0-1.5 0.60-0.85
Severe <1.0 <0.6

Aortic Valve Area (VMax)

Aortic valve area can be calculated by using the principle of conservation of mass — "What comes in must go out". Although VTI is a more accurate method, using maximum velocities is simpler and can generate a very close result. The simplified continuity equation is based on the concept that in native aortic valve stenosis the shape of the velocity curve in the outflow tract and aorta is similar so that the ratio of LVOT to aortic jet VTI is nearly identical to the ratio of the LVOT to aortic jet maximum velocity (V).

Aortic valve area indexed to body surface area should be considered for the large and small extremes of body surface area.

For patients with prosthetic aortic valves, patient-prosthesis mismatch is suspected when effective orifice area (EOA) indexed to body surface area <0.85 to 0.9 cm2/m2. Patient-prosthesis mismatch is considered severe when EOA index <0.65.

EOA Index (cm2/m2)
Moderate <0.85
Severe <0.65

AVA =
π*(LVOT/2)2*V1
V2

Variable Definition
V1 Subvalvular velocity (m/s)
V2 Maximum velocity across the valve (m/s)
LVOT Left ventricular outflow tract diameter (cm)
Weight Weight (kg or lb)
Height Height (cm or in)
AVA Aortic Valve Area (cm2)
AVA Index Aortic Valve Area indexed to BSA (cm2/m2)

References


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