Ch 19 Hemodynamics

Question 1

What is the VTI?

Answer 1

Distance traveled by the sample volume

Question 2

What are the Y axis and X axis of pulse wave doppler?

Answer 2

Y = Velocity

X = Time

VTI = Stroke Distance

Question 3

What is the CSA for circular geometry of valves?

Answer 3

CSA = 3.14 (D/2) ² = 0.785 (D)²

Question 4

What is the formula for Regurgitant Volume?

Answer 4

SV (Total) - SV (Forward)

Question 5

What is the equation for regurgitant fraction?

Answer 5

Regurgitant Fraction = [Regurgitant Volume] / [SV_Total]

Regurgitant Volume = SV_Total - SV_forward

Question 6

What is the value for Normal/Trivial Regurgitant Volume?

Answer 6

< 20 cc

Question 7

What is the value for MILD Regurgitant Volume?

Answer 7

20 - 30 cc

Question 8

What is the value for Moderate Regurgitant Volume?

Answer 8

30 - 60 cc

Question 9

What is the value for Severe Regurgitant Volume?

Answer 9

>60 cc

Question 10

What is the value for normal / trivial regurgitant fraction?

Answer 10

<20 %

Question 11

What is the value for MILD regurgitant fraction?

Answer 11

20 - 30%

Question 12

What is the value for Moderate regurgitant fraction?

Answer 12

30 - 50%

Question 13

What is the value for Severe regurgitant fraction?

Answer 13

>50%

Question 14

What are the equatons for Regurgitant volume of AI using stroke volumes only?

Answer 14

SV (AV) - SV (MV)

Question 15

What are the equatons for Regurgitant volume of MR using stroke volumes only?

Answer 15

SV MV - SV AV

Question 16

What is the formula to evaluate if shunt is present?

Answer 16

Qp / Qs

Qp = CSA * VTI (PA)

Qs = CSA * VTI (LVOT)

Question 17

What is considered a significant shunt?

Answer 17

Qp / Qs >>> 1.5 / 1