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Echocardiography > Hemodynamics & Auscultation > Flashcards

Flashcards in Hemodynamics & Auscultation Deck (73):
1

event responsible for the first heart sound

closure of the AV valves

2

event responsible for 75% of ventricular filling

rapid early filling in diastole

3

event responsible for 10-30% of ventricular filling

end-diastole atrial contraction/atrial kick/late filling

4

percentage of filling provided by early filling

75%

5

percentage of filling provided by atrial contraction

10-30%

6

event responsible for the second heart sound

closure of the semilunar valves

7

cardiac phase that lengthens and shortens with heart rate

diastasis

8

hibernation

reversible ischemia of a segment of heart wall

9

normal amount of concentric thickening and contraction expected during systole

30%

10

normal BP

120/80 mmHg

11

high BP threshold

140/90 mmHg, taken on two occasions

12

borderline high BP

130/85 mmHg

13

low BP threshold

90/60 mmHg

14

phase responsible for 2/3 of cardiac cycle

diastole

15

phase responsible for 1/3 of cardiac cycle

systole

16

fraction of cardiac cycle occupied by diastole

2/3

17

fraction of cardiac cycle occupied by systole

1/3

18

describe pulse pressure

difference in arterial blood pressure between systole and diastole

19

formula for pulse pressure

BPsystole - BPdiastole

20

describe mean arterial pressure

average arterial blood pressure over one full cardiac cycle

21

formula for MAP

diastolic method: BPdiastole + (pulse pressure)/3
=BPdiastole + 1/3(BPsystole-BPdiastole)
systolic method: BPsystole + 2/3(BPdiastole)

22

MAP

mean arterial pressure

23

simplified Bernoulli's equation

4v^2

24

describe pressure gradient

difference in pressures btwn two adjacent locations in the heart, within the same cardiac phase

25

formula for change in pressure along a flow path

simplified Bernoulli's = 4v^2

26

normal LV blood pressures, systole/diastole

100-140 / 3-12 mmHg

27

normal RV blood pressures, systole/diastole

15-30 / 2-8 mmHg

28

normal LA blood pressures

mean 2-12 mmHg

29

normal RA blood pressures

mean 2-8 mmHg

30

describe stroke volume

blood volume leaving ventricle per contraction

31

formula for stroke volume using volumes

EDV-ESV

32

describe cardiac output

blood volume leaving ventricle per minute

33

formula for cardiac output

SV x HR

34

describe cardiac index

blood volume leaving the ventricle per minute, relative to body size

35

formula for cardiac index

CO/BSA

36

BSA

body surface area

37

normal stroke volume

70-100 mL

38

normal cardiac output

4-8 L/min

39

normal cardiac index

3-4 L/min^2

40

formula for BSA

root of [weight(kg) x height(cm)]/60

41

formula for stroke volume using LVOT measurements

CSA x VTI = πr^2 x VTI

42

preload

end-diastolic volume and how it affects the length-tension relationship

43

Frank-Starling Law

relates ability to stretch to contractility
more preload = larger ventricle = increased longitudinal stretching of the myocardial fibres = increased tension -> greater contractile force required for ejection

44

What relationship is demonstrated by the Frank-Starling Law?

Length-Tension relationship of the ventricle

45

formula for cross sectional area

πr^2

46

Length-Tension relationship of the ventricle

relates ability to stretch to contractility
more preload = larger ventricle = increased longitudinal stretching of the myocardial fibres = increased tension -> greater contractile force required for ejection

47

afterload

systemic resistance that the ventricles must pump against

48

Interval-Strength relationship of the ventricle

relates time for ventricle to fill vs strength contraction required (interval-strength)
affects HR: longer interval btwn heartbeats = increased preload, results in stronger contraction required for ejection

49

describe inotropic force

relates contractile force to contractile speed (force-velocity):
force required for ejection affects the velocity of ventricle muscle fibre contraction

50

describe chronotropic force

relates time for ventricle to fill vs strength contraction required (interval-strength)
affects HR: longer interval btwn heartbeats = increased preload, results in stronger contraction required for ejection

51

Which maneuver can be used to decrease venous return, stroke volume, and cardiac output?

Valsalva maneuver

52

Which maneuver can be used to increase venous return, stroke volume, and cardiac output?

amyl nitrate inhalation

53

Force-Velocity relationship of the ventricle

relates contractile force to contractile speed (force-velocity):
force required for ejection affects the velocity of ventricle muscle fibre contraction

54

factors that affect afterload

viscosity
arterial resistance (systemic BP, HTN)
vascular geometry (stenosis, structural anomalies)
valvular geometry (stenosis, structural anomalies)

55

factors that affect contractility/inotropic force

increased inotropic force: medications
decreased inotropic force: disease, hypertrophic or fibrosed heart muscle, hypoxia

56

factors that affect chronotropic force

increased chronotropic force: adrenaline (sympathetic nervous system)
decreased chronotropic force: medications, relaxation, high fitness level

57

phases of systole

isovolumic contraction time, ventricular systole

58

phases of diastole

isovolumic relaxation time, early filling, diastasis, late filling

59

normal IVCT

30-50 ms

60

normal systolic ejection time

300 ms

61

In which direction does the muscle contraction progress through the ventricle during systole?

apex to base

62

normal aortic blood pressure, systole/diastole

100-140 / 60-90 mmHg (systole matches LV pressures)

63

What marks the transition between IVCT and systole, causing the aortic valve to open?

The LV to aorta pressure gradient must be exceeded.
The rising IVCT pressures in the LV exceed the diastolic aortic pressure (Ao dia 60-90 mmHg, usually around 80)

64

What marks the transition between systole and IVRT, causing the aortic valve to close?

The LV to aorta pressure gradient must fall.
The risen systolic pressures in the Ao exceed the emptied LV pressure (Ao sys 100-140 mmHg)

65

normal IVRT

50-100 ms

66

What marks the transition between IVRT and diastole, causing the mitral valve to open?

The LA to LV pressure gradient must be exceeded.
The rising filling pressures in the LA exceed the LV pressure (LA mean 2-12)

67

What marks the transition between diastole and IVCT, causing the mitral valve to close?

The LA to LV pressure gradient must fall.
The risen IVCT pressures in the LV exceed the emptied LA pressures.

68

normal early filling time

150-250 ms

69

What occurs during diastasis?

atrioventricular pressure gradient equalizes very briefly, dependant on heart rate

70

normal diastasis time

variable, dependant on heart rate

71

normal late filling time

???

72

normal pulmonary artery pressure, systole/diastole

15-30 / 4-12 mmHg

73

normal RVSP

under 35 mmHg