Echocardiography

Question 1

How do we determine pressure change across a valve?

Answer 1

change in pressure = 4 x velocity^squared

it’s important to remember that RVSP is 4v^2 + R atrial pressure

Question 2

how do we work out the aortic valve area?

Answer 2

we use easier to measure parameters

AVA = CSA (LVOT) * V(LVOT)/ V(aortic valve)

(based on the concept that:

flow velocity (LVOT) x cross sectional area (LVOT) = flow velocity (aortic) x cross sectional area (aortic))

Question 3

how would you determine the aortic valve pressure?

what about across a VSD?

Answer 3

4 * aortic flow velo ^2

VSD = 4 * VSD velo ^2

Question 4

what is the meaning of the E wave and the A wave in echo?

what happens throughout life to the comparison between these readings?

Answer 4

the E wave is the “early” wave of diastolic filling

the A is the atrial contraction wave

early in life, the E wave is predominant.

in middle age, they are reasonably similar

later in life, with stiffer myocardium (etc) the E wave becomes less contributory while the A wave becomes more important