Echo- Valves

Question 1

Flow Rate General Formula

Answer 1

(0.785xDsquared) x Velocity (cm/s)

Question 2

Jet Volume General Formula

Answer 2

(0.785 x Dsquared) x VTI (cm)

Question 3

Pressure Gradient (Bernoulli)

Answer 3

PG= 4Vsquared

Question 4

Continuity Equation

Answer 4

(Area1 x VTI1) = (Area2 x VTI2)

Question 5

Continuity Equation for AVA

Answer 5

AVA = (07.85 x LVOT diam squared) x LVOT VTI/AoV VTI

Question 6

AVA Grading

Answer 6

AVA
Normal 3-4
Mild AS 1.5-2 
Moderate AS 1-1.5
Severe AS < 1

Question 7

Aortic Stenosis grading based on gradients

Answer 7

Mild = mean gradient < 25
Mod = mean gradient 25-40
Severe = mean gradient > 40

Question 8

Definition of Pressure half time

Answer 8

PHT = time it takes for gradient between 2 chambers to fall to half its peak value.

Question 9

If given the peak velocity how do you calculate PHT

Answer 9

You calculate the velocity at 1/2 time as:
Vt1/2 = Vmax/1.4

Then you can plot that on the doppler signal and note what the time difference is between peak velocity and Vt1/2. That will give the PHT.

Question 10

How do you get mitral valve area from PHT?

Answer 10

MVA = 220/PHT

Question 11

Mitral stenosis grading by MVA

Answer 11

MVA 4-6 normal
MVA >1.5 mild
MVA 1-1.5 moderate
MVA < 1 severe MS

Question 12

Mitral stenosis grading via mean gradient.

Answer 12

Mild MS mean grad <5 mmHg
Mod MS mean grad 5-10 mmHg
Severe MS mean grad > 10

Question 13

How to calculate MR Regurgitatnt volume in general terms.

Answer 13

MR RV is the difference between the inflow volume across the MV and the outflow volume across the Ao Valve.

Question 14

MR RV formula

Answer 14

MR RV = (CSA MV x MV VTI) - (CSA LVOT x LVOT VTI)

which means…

MR RV = (0.785 MV diam squared x MV VTI) - (0.785 LVOT diam squared x LVOT VTI)

Question 15

How to calculate AI Regurgitant Volume in general terms

Answer 15

AI RV is the difference between the LVOT outflow volume and the MV inflow volume

What comes into the LV across the MV is less than what is going out across the LVOT due to the increased LV volume from the AI.

Question 16

AI RV formula

Answer 16

AI RV = (0.785 LVOT diam squared x LVOT VTI) - (0.785 MV diam squared x MV VTI)

Question 17

what does PISA help us to calculate?

Answer 17

Effective Regurgitant Orifice Area.

Question 18

EROA can be used to calculate what?

Answer 18

Regurgitant Volume

Because Volume is area x VTI. So if we know the area of the regurgitant jet, we can measure the VTI and then calculate the Regurgitant volume

Question 19

What is the EROA formula?

Answer 19

EROA = (2 pi r squared x aliasing velocity) / Vmax