Prosthetic aortic valve stenosis can be classified based on a number of objective parameters.
Patient selection: prosthetic aortic valve
Conditions: normal or near normal stroke volume (50-70 mL)
Parameters:
(1) peak velocity in meters per second
(2) mean gradient in mm Hg
(3) Doppler velocity index
(4) effective orifice area in square cm
(5) contour of the jet velocity through the prosthetic valve
(6) acceleration time in milliseconds
|
Parameter
|
Finding
|
Stenosis
|
|
peak velocity
|
< 3
|
none (normal)
|
|
|
3-4
|
possible
|
|
|
>4
|
significant
|
|
mean gradient
|
<20
|
none (normal)
|
|
|
20-35
|
possible
|
|
|
>35
|
significant
|
|
Doppler velocity index
|
>=0.3
|
none (normal)
|
|
|
0.25-0.29
|
possible
|
|
|
<0.25
|
significant
|
|
effective orifice area
|
>1.2
|
none (normal)
|
|
|
0.8-1.2
|
possible
|
|
|
<0.8
|
significant
|
|
contour of the jet velocity
|
triangular, early peaking
|
none (normal)
|
|
|
triangular to intermediate
|
possible
|
|
|
rounded, symmetrical
|
significant
|
|
acceleration time
|
< 80
|
none (normal)
|
|
|
80-100
|
possible
|
|
|
>100
|
significant
|
