Echo Physics 101

Question 1

Frank-Starling Principle aka

Answer 1

length tension relationship

Question 2

what is the Frank-Starling Principle

Answer 2

force of contraction is greater when the LV muslce is stretched prior to contraction increased by preload

Question 3

the degree of the stretch of the cells in the ventricular wall is determined by the ___

Answer 3

volume of blood within the chamber

Question 4

more blood to the heart (preload), greater tension, greater forced generated during systole = ____ SV

Answer 4

greater

Question 5

SV

Answer 5

stroke volume

Question 6

what is SV

Answer 6

the amount of blood ejected with each beat of the heart

Question 7

what two ways can stroke volume be calculated and their formulas

Answer 7

2d: SV = EDV-ESV
doppler: SV= CSA x VTI

Question 8

CSA means

Answer 8

cross sectional area

Question 9

VTI means

Answer 9

velocity time integral

Question 10

normal stroke volume at rest

Answer 10

50-100mL

Question 11

what is cardiac output

Answer 11

how much blood is pumped out of the heart in one minute

Question 12

cardiac output formula

Answer 12

CO = SV x HR

Question 13

normal CO

Answer 13

4-6L/min

Question 14

what is cardiac reserve

Answer 14

amount of blood the heart is capable of pumping beyond the normal CO of a resting HR

Question 15

cardiac reserve is____ in athletes, _____ in elderly

Answer 15

higher
lower

Question 16

cardiac index and formula

Answer 16

cardiac output indexed to accommodate for body surface area

CI = CO/BSA

Question 17

SV = blood pumped to heart per ___

Answer 17

beat

Question 18

CO = blood pumped from the ventricle in ____

Answer 18

one minute

Question 19

chronotropic force

Answer 19

heart rate

Question 20

increased HR = ____ the LV filling time (diastole)

Answer 20

decrease

Question 21

SNS increases ____ and ____

Answer 21

chronotropic force
inotropic force

Question 22

SNS _____ HR

Answer 22

increases

Question 23

PNS ____ chronotropic force/HR

Answer 23

decreases

Question 24

preload is what

Answer 24

the amount of blood in the ventricle at end-diastole (volume load delivered to ventricle)

Question 25

increased preload = _____ EDV/SV/CO

Answer 25

increased

Question 26

decreased HR = ____ diastole time, ____ filling time, _____ preload

Answer 26

increased x3

Question 27

increased HR = ____ diastole time, ____ filling time, _____ preload

Answer 27

decreased x3

Question 28

preload factors (2)

Answer 28

filling time venous return

Question 29

increased venous return = _____ preload

Answer 29

increased

Question 30

3 causes of increased venous return

Answer 30

increased blood volume/venous pressure Decreased intrathoracic pressure

Question 31

decreased intrathoracic pressure = _____ venous return

Answer 31

increased

Question 32

what decreases intrathoracic pressure

Answer 32

breathing = diaphragm moves down

Question 33

inspiration ______ VR to heart

Answer 33

increases

Question 34

standing ____ VR

Answer 34

decreases (gravity pulls down to legs)

Question 35

squatting _____ VR

Answer 35

increases (squeezes blood to heart)

Question 36

valsalva maneuver ____ VR and ____

Answer 36

decreases SV

Question 37

valsalva ____ intrathoracic pressures

Answer 37

increases

Question 38

is afterload opposite to preload

Answer 38

no

Question 39

what is afterload

Answer 39

resistance to ventricular emptying (pressure LV has to squeeze against)

Question 40

increased afterload = ____ SV/CO

Answer 40

decreased

Question 41

what affects afterload (3)

Answer 41

hypertension viscosity of blood valvular stenosis

Question 42

Law of Laplace and formula

Answer 42

tension in walls depends on 1. pressure of its contents, 2. radius Wall tension = cavity pressure (r) / wall thickness x 2

Question 43

contracility AKA (2)

Answer 43

inotropic force, force-velocity relationship

Question 44

contracility is the ______ of ____ at a given preload and afterload

Answer 44

force contraction

Question 45

is contracility related to the Frank-Starling mechanism

Answer 45

no

Question 46

____ force of contraction = increased SV

Answer 46

increased

Question 47

SNS _____ contracility

Answer 47

increases

Question 48

negative inotropic response = LV cannot _____ due to ____

Answer 48

contract enough structural disorganization (disease)

Question 49

positive inotropic response

Answer 49

medications can make it easier for the heart to contract by altering the sympathetic nervous system

Question 50

length-tension relationship vs force-velocity relationship

Answer 50

frank-starling principle (preload) vs inotropic force/contracility/afterload

Question 51

increased preload = _____ tension = ____ SV

Answer 51

increased x2

Question 52

increased afterload = ____ stroke volume/CO

Answer 52

decreased

Question 53

bernoulli principle formula

Answer 53

ΔP= 4V^2

Question 54

what is bernoulli's principle used to measure in echo

Answer 54

measur pressure gradients

Question 55

what angle does pressure gradient measurements need

Answer 55

0

Question 56

pressure gradients may be underestimated due to (3)

Answer 56

incorrect doppler angles viscous friction from blood hitting walls (stenosis = >10mm) increased proximal velocity (>1.2m/sec)

Question 57

20 degree offset from flow diretion = ___ underestimation of blood flow velocity

Answer 57

6%

Question 58

systolic pressure in the PA = systolic pressure in the ____ (assuming there is no blockage in the outlfow)

Answer 58

RV

Question 59

SPAP = RVSP (what does it mean)

Answer 59

systolic pulmonary artery pressure = right ventricular systolic pressure

Question 60

TR pressure gradient is the ____ between the RV and RA pressure during systole

Answer 60

difference

Question 61

TRpg formula (and what equation it originally came from)

Answer 61

TRpg = 4TRmax vel came from bernoullis

Question 62

pressure in RV = add the pressure in the ___ to the ____

Answer 62

RA TR pressure gradient

Question 63

RVSP formula (not with a four)

Answer 63

RVSP = TR Δpress +RA press

Question 64

RVSP formula (with a four)

Answer 64

RVSP = 4(peak TR vel)^2 +RAP

Question 65

normal RVSP

Answer 65

<35mmHg

Question 66

we use ____ and _____ to come up with our rap estimates

Answer 66

IVE diameter collapsibilty

Question 67

IVC ≤_____

Answer 67

21mm

Question 68

≥

Question 69

≥

Question 70

>21mm <50% +RAP = vs RVSP SPAP

Answer 70

15 vs high

Question 71

flow rate at any given point must remain _____

Answer 71

constant

Question 72

velocities at a narrowing _____ than the velocities before or after the narrowing

Answer 72

greater

Question 73

stroke volume must remain constant at any _____

Answer 73

2 points in the heart

Question 74

all 4 valves should have the same ___ in the absence of a shunt or regurgitation

Answer 74

SV

Question 75

SV = (formula)

Answer 75

SV = CSA x VTI

Question 76

CSA = (formula)

Answer 76

CSA = 0.785 x diameter^2

Question 77

SV must be the same throughout the LVOT and the ___

Answer 77

AV

Question 78

AVA = (formula)

Answer 78

AVA= (A1 x V1)/V2

Question 79

AVA stands for

Answer 79

aortic valve area

Question 80

2 most important principles/equations in echo principles

Answer 80

Bernoulli's continuity rule