Physiology

Question 1

what is “sarcomere length” a surrogate for?

Answer 1

preload

Question 2

La Place equation for wall stress?

Answer 2

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

Question 3

what is another word for LVEDV?

Answer 3

Preload

Question 4

what is another word for myocardial wall stress?

Answer 4

afterload

Question 5

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

Answer 5

shift down

Question 6

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

Answer 6

shift up

Question 7

what are the axes of a starling curve?

Answer 7

SV (y) vs. Preload (x)

Question 8

what are the axes of a Force-Tension curve?

Answer 8

SV (y) vs. Wall Stress (x)

Question 9

what will amlodipine do to starling curve and why?

Answer 9

shift up

decreases afterload which is not on x or y axis.

Question 10

what point on P-V curve is preload?

Answer 10

a (bottom right)

Question 11

what point on P-V curve is afterload?

Answer 11

c (top left)

Question 12

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

Answer 12

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

Question 13

meaning of prominent v wave on RHC?

Answer 13

TR

Question 14

meaning of canon a wave on RHC

Answer 14

complete HB or VT

Question 15

meaning of exaggerated y descent on RHC

Answer 15

constriction

Question 16

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

Answer 16

a, c, x, v, y

Question 17

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

Answer 17

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

Question 18

what do the v, y represent in JVP waveform?

Answer 18

v- atrial diastole

y- atrial emptying

Question 19

are LV and RV pressures concordant or discordant in myocardial restriction

Answer 19

concordant

Question 20

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

Answer 20

discordant

Question 21

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

Answer 21

right after T wave

Question 22

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

Answer 22

no

Question 23

what does TR do to thermodilution estimate of CO?

Answer 23

underestimates CO

Question 24

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

Answer 24

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

Question 25

normal mixed venous sat

Answer 25

65-75%

Question 26

what value is assumed for FICK eq’n?

Answer 26

oxygen consumption

Question 27

eq’n for LVOT dopper CO

Answer 27

CO = CSA x VTI x HR

note: CSA = Πr2/2

Question 28

what acts as a surrogate for Fick CO?

Answer 28

Mixed Venous O2 (MVO2)

Question 29

what does MAP/CI = ?

Answer 29

SVR

Question 30

MAP = ?

Answer 30

(2DBP + SBP)/3

Question 31

PVR = ?

Answer 31

(mean PAP - PCWP) / CO

Question 32

PVR transplant threshold

Answer 32

< 4 woods units

Question 33

what Qp/Qs do you close shunt?

Answer 33

> 1.5

Question 34

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

Answer 34

Eisenmenger’s (conversion to R–>L shunt)

Question 35

Qp/Qs = ?

Answer 35

(SAO2-MVO2)/(SAO2- PAO2)

Question 36

MVO2 equation

Answer 36

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

Question 37

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

Answer 37

7

Question 38

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

Answer 38

5