Exam 1 Lecture 3 (1-24-23) CO, VR, and Pressure Volume Loops (Andy's cards) Flashcards

1
Q

What factor will cause significant right or left shift in the cardiac output curve?

A

Changes in thoracic pressure.

(19:12)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is normal intrathoracic pressure (intrapleural pressure)?

A

-4 mmHg or -5 cmH2O

(19:58)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What happens to our pleural pressure as we inspire or breathe in?

A

Intrapleural pressure decreases (more negative) and helps pulls more air in to the lungs. (20:30)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What does a drop in pleural pressure do to the filling of the heart?

A

If there is a more negative intrapleural pressure, the negative pressure will help draw blood from the peripheral veins in to the thorax increasing filling in the right side of the heart. (21:00)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Relating to thoracic pressure, what can cause the cardiac output curve to shift left?

A
  1. During inspiration
  2. Negative Pressure Ventilator (“Iron Lung”)

(22:49)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What does an increase in thoracic pressure do to the cardiac output curve ?

A

Shift the cardiac output curve to the right, indicating it is more difficult to fill the heart back up with blood. To overcome the increase thoracic pressure, the pressure in the venous system will need to be increased in order get blood back into the chest.

(22:37)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Relating to thoracic pressure, what can cause the cardiac output curve to shift right?

A
  1. Cracking the rib cage will result in the pressure in the chest to go from sub-atmospheric to atmospheric.
  2. Positive Pressure Ventilation
  3. Cardiac Tamponade
  4. Pleural Effusion (not mentioned specifically in lecture but it fits I think)
    (25:00)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

If we have a normal venous return curve and RAP of 5 mmHg. What happens to CO?

A

The increase right atrial pressure is a result of the heart not pumping effectively. Blood accumulates in the right atrium, increasing right atrial pressure which makes venous return more difficult which will decrease cardiac output.

(27:33)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the formula for Venous Return?

A

Venous Return = (Systemic Filling Pressure - Right Atrial Pressure) / (Resistance to Venous Return)

(28:00)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Where will the CO Curve shift with β1 agonist administration?

A

Curve will shift left (enhanced)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Where will CO Curve shift in a depressed or sick heart?

A

Curve will shift right (depressed)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What can cause the shift from point A to point B?

A

Giving an arterial-specific vasodilator (Sodium Nitropursside) will decrease the RVR and SVR, increasing venous return which will increase RAP of the system, increasing cardiac output.

(32:45)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What can cause the shift from point A to point B?

A

Giving a venular-specific vasodilator (Nitroglycerin) will decrease CVP and PSF of the venous return curve which will lead to a decrease in cardiac output.

(35:00)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What can cause the shift from point A to point B?

A

Giving a mixed vasodilator will dilate the veins which will reduced PSF and dilate the artery which will reduce the RVR and increasing the slope of the VR Curve.

(37:00)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How do you increase the size and position of the venous return curve?

A

Increase Volume or Decrease Compliance (ie: increase venous tone)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How do you decrease the size and position of the venous return curve?

A

Decrease Volume or Increase Compliance (decrease venous tone)

(38:00)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How will the slope of the VR Curve/CO be affected by an increase in SVR?

A

↑SVR will decrease the slope of the VR curve.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is causing the decreased slope and increased PSF of the red VR curve?

A

Arterial Vasoconstriction will increase RVR, decreasing the slope of the VR Curve.

Venous Vasoconstriction will increase tone of the veins and increase PSF.

(39:00)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Which letter represents initial compensation to heart failure with an increase to sympathetic activity and increase venous tone to provide normal cardiac output?

A

Letter C (40:30)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Which letter represents less sympathetic activity as a result from increasing fluid retention to compensate for heart failure?

A

Letter D (43:30)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Which letter represents fluid retention to establish new normal sympathetic activity to illustrate long term compensation for heart failure.

A

Letter E (44:00)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Which letter represents no compensation after heart failure?

A

Letter B (46:50)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

With heart problems the body will retain _________ in order to have a normal cardiac output.

A

retain fluid

(48:30)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the formula for cardiac index?

What are the units for Cardiac Index?

A

Cardiac Output / Surface Area

L/min/m2

(54:41)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

At what age does is our cardiac index the highest?

What will that cardiac index be?

A

10 years old

Cardiac Index peaks at 4.5 L/min/m2

(55:00)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What would the cardiac index be in a healthy 80-year-old person?

A

2.4 L/min/m2

(55:20)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What would the cardiac index be in a healthy middle age person?

A

3 L/min/m2

(55:30)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is our cardiac index dependent on?

A

Metabolic Rate
TPR (Total Peripheral Resistance)
SVR (Systemic Vascular Resistance)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

For cardiac index what is TPR and SVR controlled by?

A

Metabolic requirements of the tissue.

If the tissues need lots of oxygen and nutrients, TPR and SVR will decrease to make it easier for the heart to pump.

(56:30)

30
Q

Increase Metabolism will lead to a _____________ in cardiac index/output.

A

increase
(57:00)

31
Q

What does Arterial Pressure divided by Vascular Resistance equal to?

A

Cardiac Output = Arterial Pressure / Vascular Resistance

(56:40)

32
Q

What are diseases or conditions that will result in a high cardiac index / cardiac output.

A
  1. Beriberi
  2. AV Shunts
  3. Hyperthyroidism
  4. Anemia
  5. Pulmonary Disease
  6. Paget’s Disease
33
Q

What kind of deficiency will a person have with Beriberi?
What is this deficient “thing” used for in the body?

A

Vitamin B1.

Vitamin B1 is used as a cofactor for ATP production in the body.

(57:40)

34
Q

In optimal conditions, how many ATPs are produced when glucose is combined with oxygen?

A

36 ATPs

(58:00)

35
Q

How does Beriberi increase an individual’s metabolism?

A

With Vitamin B1 deficiency, the body is not as efficient in producing ATP. Therefore, more glucose will need to be utilize to produce adequate energy. (58:50)

36
Q

What are diseases or conditions that will result in a low cardiac index / cardiac output.

A
  1. Removal of both arms and legs
  2. Hypothyroidism

(61:25)

37
Q

What drug uncouples metabolism and can cause decrease in arterial pressure?

A

Dinitrophenol

38
Q

What is a dangerous side effect of Dinitrophenol?

A

Increase body temperature and overheating

39
Q

Which letter will display the optimal length of cardiac myocytes?

A

B.

(80:55)

40
Q

If there is an increase in preload what happens to EDV?
SV?
ESV?

A

Increase EDV.
Increase SV.
ESV will remain constant.

41
Q

If there is an decrease in preload what happens to EDV?
SV?
ESV?

A

Decrease EDV.
Decrease SV.
ESV will remain constant.

42
Q

If there is an increase in afterload at a constant preload what happens to SV?
ESV?

A

Due to the increase afterload, the heart will have to pump longer and harder to generate enough pressure to open the aortic valve this will cause a shorter period time for ejection, decreasing SV.

Less blood ejected means an increase in ESV.

43
Q

What are two reasons why SV will be decreased in a heart with an increased afterload?

A
  1. ↑afterload causes ↑ contractility causes shorter ejection time thus ↓SV.
  2. ↑ aortic pressure causes AV to shut faster thus decreasing SV.

(86:00)

44
Q

If there is a decrease in afterload at a constant preload what happens to SV?
ESV?

A

The decrease afterload will open the aortic valve sooner and more time will be spent on ejection, increasing SV.

Increase ejection time, means decrease ESV

(87:00)

45
Q

If there is an increase in contractility at a constant preload what happens to SV?
ESV?

A

Increase in contractility will increase SV and decrease ESV.

46
Q

If there is a decrease in contractility at a constant preload what happens to SV?
ESV?

A

Decrease in contractility will decrease SV and increase ESV.

(89:00)

47
Q

What happens to the left ventricular volume of blood during phase 2 of the cardiac cycle with mitral valve regurgitation?

A

Blood in the left ventricle will move into the left atria when ventricular pressure is higher than atrial pressure.

48
Q

What happens to left ventricular volume of blood during phase 3 of the cardiac cycle with mitral valve regurgitation?

A

The majority of blood will be ejected through the aorta, but there will also be some blood that will go into the left atria. (91:00)

49
Q

What happens to left ventricular volume of blood during phase 4 of the cardiac cycle with mitral valve regurgitation?

A

During the initial part of phase 4, blood in the left ventricle leaks into the left atria because ventricular pressure > atrial pressure.

50
Q

During what phases will their be backwards movement of blood in mitral valve regurgitation?

A

Phases 2, Phase 3, and early part of phase 4. Blood in the left ventricles will move back to the left atria.

(93:00)

51
Q

How does the body compensate for mitral valve regurgitation?

A

Blood volume expansion (increase CVP)

(94:00)

52
Q

Mitral valve stenosis will be similar to which of the following?

A. Reduced Preload
B. Reduced Afterload
C. Increased Preload
D. Increased Afterload

A

A. Reduced Preload

53
Q

What happens to SV and EDV in mitral stenosis?

A

Decrease in SV due to a decrease in EDV.

There is poor filling d/t a high resistance mitral valve

54
Q

How does the body compensate for mitral valve stenosis?

A

Increase PSF (increase CVP)

55
Q

What happens to blood in the aorta during phase 4 of the cardiac cycle with aortic valve regurgitation?

A

Blood leaks from the aorta to the left ventricle during the later part of phase 4 due to the pressure difference between the aorta and left ventricle. (98:30)

56
Q

What happens to blood in the aorta during phase 1 of the cardiac cycle with aortic valve regurgitation?

A

Aortic pressure will be greater than ventricular pressure in phase 1 resulting to an increase in volume in the left ventricle.

57
Q

How does the body compensate for aortic valve regurgitation?

A

Fill the heart up with more blood, increase CVP

58
Q

Why does an aortic valve stenosis result in a high afterload?

A

Blood is pumping through an aortic valve with a higher than normal resistance will result in a higher afterload. (101:00)

59
Q

What happens to the left intraventricular pressure of the heart if there is aortic valve stenosis?

What happens to the aortic pressure if there is aortic valve stenosis?

A

The left intraventricular pressure of the stenotic heart will be higher than normal.

The aortic pressure of the stenotic heart will be lower than normal.

(102:00)

60
Q

What happens to pulse pressure in someone with aortic valve stenosis?

A

Pulse Pressure decreases due to increased resistance.

(↓PP from ↑afterload)

61
Q

How does the body compensate for aortic valve stenosis?

A
  1. The body will increase filling pressure (increase CVP)
  2. Increase HR d/t decrease SV over time.

(104:00)

62
Q

Which of the following will most likely cause an elevated heart rate?

A. Aortic Regurgitation
B. Mitral Regurgitation
C. Aortic Stenosis
D. Mitral Stenosis

A

C. Aortic Stenosis

63
Q

If there is depressed contractility in someone with heart failure, what treatment will be given to increase SV and cardiac output?

A

Treat depressed contractility with an afterload reducer.

(106:00)

64
Q

How many breathes do we take in a minute?

A

10-12 breaths/min

(108:34)

65
Q

What happens to CVP during inspiration.

A

During inspiration, the diaphragm contracts and expands thoracic cavity decreasing intra-thoracic pressure, decreasing CVP, increasing venous return and cardiac output. (109:00)

66
Q

How does the pulmonary arterial pressure drop during inspiration?

A

The lungs and blood vessels are very compliant. As the intra-thoracic pressure becomes more negative during inspiration the lungs and blood vessels are “pulled out” (dilated?) making the interior pressure of the blood vessels drop (↓ PAP).

(111:00)

67
Q

How does a decreased PAP increase CO?

A

Reduction of PAP, reduces the afterload the right heart has to pump against. The combination of this with increase venous return from the more negative intra-thoracic pressure will increase cardiac output. (112:00)

68
Q

What vessel feeds into the left atria of the heart?

A

Pulmonary veins

69
Q

What happens to filling in the left side of the heart during early inspiration?

What will happen to MAP?

A

Early inspiration will reduce thoracic pressure to fill the lungs and right side of the heart with blood and not so much to the left heart.

MAP decreases due to blood pooling temporarily in the lungs and poor filling of the left heart. MAP normalizes after a couple of heartbeats.

(114:30)

70
Q

How does positive pressure ventilation initially affect cardiac output?

How does PPV affect CO over time?

A

The initial increase of intrathoracic pressure from PPV will push blood into the right and left side of the heart and increase CO.

Overtime, PPV will impair venous return.

(117:00)

71
Q

As cardiac output and cardiac index increases, oxygen consumption _____________.

A

Increases (proportional relationship)

72
Q

How will the slope of the VR Curve be affected by a decrease in SVR?

A

Decreasing the SVR will make the slope of the VR curve steeper, increasing CO.