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Aortic Valve

You'll see there is a question in the text - if you know the answer let me know.

Aortic Valve

2D
Inspect all leaflets.
?Tricuspid. Bicuspid closed looks like tricuspid - need to look when open.
PLAX R (top), non (bottom).
PSAX R (top), N (left), L (right)

Aortic Stenosis

Colour
Increased flow velocity and/or turbulent flow downstream.
Can’t tell from closed valve whether tri or bicuspid - need to look at it when it is open. Bicuspid valves have a non central closure line on M-mode.
If AS under 70 then bicuspid valve likely; over 70 likely tricuspid with other pathology.

CW and PW
Through valve for forward flow velocity. Peak velocity relates to peak pressure gradient via the simplified Bernoulli equation. If LVOT flow >1m/s or Vmax <3m/s, need to measure peak LVOT velocity with PW and use full Bernoulli.
Mean gradient by tracing doppler envelope - more useful than peak gradient.
Gradients are overestimated if increased SV (AR, preg) or underestimated if reduced SV (poor LV).
Most accurate to measure valve area by continuity equation. Valve area will be still be underestimated if poor LV with low flow. This suggested by mean gradient of <30 and can be confirmed with dobutamine stress echo (poor LV will show little increase in VTI with dobutamine).
Measure LVOT (to calculate CSA), VTI of LVOT with PW and VTI of aorta with CW.
LVOT and annulus should be measured in systole.

SVA = SVB
or
CSAA x VTIA = CSAB x VTIB
Therefore
EOA = (CSA LVOT x VTI LVOT) / VTI AV

If it is difficult to measure LVOT diameter then work out the velocity ratio (V1/V2). V1 = velocity proximal to stenosis and V2 = distal velocity. The bigger the difference between the velocities the higher the gradient and the lower the velocity ratio. More correct to measure VTI ratio but not commonly done and I don’t know the figures - would the ratio be the same?



Aortic regurgitation

2D
Measure aorta

M-mode
If severe can hit anterior MV leaflet, pushing it backwards in diastole with premature valve closure. Fluttering seen on M-mode.
Width of jet in relation to LVOT (colour M-mode).

Colour
Measure vena contracta (narrowest colour at valve level perpendicular to jet rather than LVOT) in PLAX.
Reducing the aliasing velocity will mean lower flow rates detected and regurg will look more severe - make sure >50.

Spectral
CW in A5C aligned with reurg jet.
Trace is faint if mild and gets denser with severity.
Measure PHT (rate of deceleration) of jet (best for acute regurg). Gets shorter with severity.

Suprasternal view - look for diastolic flow reversal with PW. Brief reversal normal but pandiastolic if mod to severe. Measure VTI of flow reversal.

Regurgitant volume calculated from difference between LVOT outflow and MV inflow. These would normally be the same but LV outflow will increase if AR. Measurement prone to error.
Measure diameter of MV annulus in A4C.
Measure VTI of MV inflow at annulus (PW).

SV MV = CSAMV x VTIMV

Measure SV of AV in the same way.

RV = SV LVOT - SVMV

RF = RV / SVAV or MV? x 100

ROA = RV / VTIAR
(VTIAR measured with CW)