PSL301: Cardio 4 Flashcards Preview

PSL301 > PSL301: Cardio 4 > Flashcards

Flashcards in PSL301: Cardio 4 Deck (55):
1

First heart sound

"lub"
Closing of AV valves

2

Second heart sound

"dup"
Closing of semilunar valves

3

Ausculation

Listening to heart

4

What might cause a leaky aortic valve?

Calcification of aortic walls (hardening)

5

What happens when the valves don't close properly?

Blood leaks backwards

6

When the aortic valve doesn't fully close, what sound is made?

sloshing sound

7

Aortic regurgitation

Leaking aortic valve (backflow into left ventricle)

8

Aortic regurgitation seen on PV loop

- Pressure same as normal
- Vol increased

9

Aortic stenosis

Opening of aortic valve is narrower

10

Aortic stenosis seen on PV loop

- Volume same as normal
- Pressure increased

11

2 phases of cardiac cycle

1. diastole
2. systole

12

How does systole pump blood?

Contraction raises pressure
Blood flows down pressure gradient

13

Events on the right & left side of the heart are the ___, but pressure are lower on the ___

Same
Right

14

ESV =

end systolic volume
65 mL

15

EDV =

end diastolic volume
135 mL

16

How much blood we are moving (CO) depends on...

- HR
- Stroke vol

17

Formula: SV

SV = EDV - ESV
Usually 70 mL

18

Inotrope

Agent that alters the force or energy of muscular contractions

19

How to maximize SV?

Higher EDV
Lower ESV
(this maximizes the difference)

20

Increase preload causes SV to...
Explain

Go up
Higher EDV

21

Define: SV

amount of blood pumped by 1 ventricle in 1 contraction

22

Formula: CO

CO = HR x SV

23

Define: CO

amount of blood pumped per ventricle per unit time

24

Unit for CO

L/min

25

Unit for SV

mL/beat

26

What is the normal CO?

5L/min

27

What is normal blood volume?

5L

28

Cardiac reserve is the difference between ___ and ___ CO

Resting
max

29

What does Frank-Starling Law of the Heart ask?

What affects stroke volumes?

30

What affects stroke volume?

- Preload (mostly)
- Afterload

31

Preload

Pressure at the end of diastole

32

Afterload

Pressure during ventricular contraction

33

What increases SV?

Increased EDV
Exercise (increase venous return)
Slow HR (allow more to fill)

34

What decreases SV?

Blood loss
Rapid HR (no time to fill)
Decreased EDV

35

Frank-Starling Law of the Heart states that...

SV increases as EDV increases

36

EDV is affected directly by...

Venous return

37

Venous return is directly affected by

- skeletal muscle pump
- Respiratory pump
- SNS

38

Force of contraction of heart is affected by...

EDV
Contractility / length of muscle fibre

39

The Starling curve shows..

relationship between stretch (EDV) & force (SV)

Increased stretch = increased pressure
Increased EDV = increased SV

40

How does increased EDV lead to increased SV?

EDV stretches the sacromere out more

41

What happens to the Starling curve as intensity of exercise increases?

Becomes higher; bigger slope
Same EDV = higher SV

42

What happens when EDV is too high?

Sacromeres stretch too much = left ventricle dysfunction

43

Example of inotrope

NE

44

How does NE affect contractility of the heart?

Starling curve looks like exercise
Same EDV = higher SV

Increase contractility

45

are NE and E positive or negative inotropes?

Positive (increase contractility)

46

Negative inotropes ___ contractility

decrease

47

Examples of negative inotropes

- B-blocker
- Ca channel blocker

48

What is the purpose of negative inotropes?

- Decrease risk of second MI
- Hypertension

49

Contractility is independent of...

- stretch
- EDV

50

Increase in contractility comes from...

- Sm stimuli
- Hormones
- more Ca++
- Drugs

51

Define: contractility

increase in contractile strength

52

SNS ___ venous contraction

increases

53

How does Sm NT affect contractility?

Bind to B1 G-proteins -> cAMP & PKA
More Ca++ binding to troponin

54

High blood pressure ___ SV

decreases

55

Only ___ affect the HR

- SNS
- PNS