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Flashcards in Physiology Deck (38):
1

what is "sarcomere length" a surrogate for?

preload

2

La Place equation for wall stress?

WS = (Pressure x Radius)/ (2 x Wall Thickness)

3

what is another word for LVEDV?

Preload

4

what is another word for myocardial wall stress?

afterload

5

what will increased afterload (e.g. phenylephrine) do to the starling curve?

shift down

6

what will decreasing afterload (e.g. clonidine, IABP) do to starling curve?

shift up

7

what are the axes of a starling curve?

SV (y) vs. Preload (x)

8

what are the axes of a Force-Tension curve?

SV (y) vs. Wall Stress (x)

9

what will amlodipine do to starling curve and why?

shift up
decreases afterload which is not on x or y axis.

10

what point on P-V curve is preload?

a (bottom right)

11

what point on P-V curve is afterload?

c (top left)

12

if the P-V curve changes in shape, what are the 3 parameters you look at to determine what made the change?

preload (a, bottom right)
afterload (c, top left)
SV

13

meaning of prominent v wave on RHC?

TR

14

meaning of canon a wave on RHC

complete HB or VT

15

meaning of exaggerated y descent on RHC

constriction

16

what is the order (top to bottom) of the JVP waveforms?

a, c, x, v, y

17

what do the a, c, x represent in JVP waveform?

a- atrial contraction
c- TV closure
x- passive atrial filling/ventricular contraction

18

what do the v, y represent in JVP waveform?

v- atrial diastole
y- atrial emptying

19

are LV and RV pressures concordant or discordant in myocardial restriction

concordant

20

are the LV and RV pressures concordant or discordant in constrictive pericarditis

discordant

21

using the PQRST complex, when should the v wave show up?

right after T wave

22

does the size of v-wave correspond with severity of TR or MR?

no

23

what does TR do to thermodilution estimate of CO?

underestimates CO

24

in very severe systolic CHF, what happens to thermodilution estimate of CO? what do you to?

overestimates CO; use used saline b/c fluid warms up by the end of catheter

25

normal mixed venous sat

65-75%

26

what value is assumed for FICK eq'n?

oxygen consumption

27

eq'n for LVOT dopper CO

CO = CSA x VTI x HR

(note: CSA = Πr2/2)

28

what acts as a surrogate for Fick CO?

Mixed Venous O2 (MVO2)

29

what does MAP/CI = ?

SVR

30

MAP = ?

(2DBP + SBP)/3

31

PVR = ?

(mean PAP - PCWP) / CO

32

PVR transplant threshold

< 4 woods units

33

what Qp/Qs do you close shunt?

>1.5

34

If the Qp/Qs is decreased in VSD, what may be the cause?

Eisenmenger's (conversion to R-->L shunt)

35

Qp/Qs = ?

(SAO2-MVO2)/(SAO2- PAO2)

36

MVO2 equation

MVO2 = 3/4SVC O2 + 1/4IVC O2

37

What's is considered a step up between mixed venous (MV) and RA?

7

38

What is considered a step up (not including MVO2 to RA)?

5