Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

_MS2 Cardio > 8/3- Cardiac Fct: Heart as a Pump > Flashcards

8/3- Cardiac Fct: Heart as a Pump Flashcards

(49 cards)

Start Studying
1
Q

T/F: Preload is the ventricular volume before systole

A

True

Preload is the ventricular volume before systole

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

T/F: Afterload is measured after contraction starts

A

True

Afterload is measured after contraction starts

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

T/F: Wall stress is closely related to blood pressure

A

True

Wall stress is closely related to blood pressure

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

T/F: Starling’s law states that an increase in preload improves cardiac performance

A

True

Starling’s law states that an increase in preload improves cardiac performance

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

T/F: Decrease in afterload improves cardiac performance?

A

True

Decrease in afterload improves cardiac performance

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

T/F: The 3 key determinants of fiber shortening are preload, afterload, and contractility?

A

True

The 3 key determinants of fiber shortening are preload, afterload, and contractility

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

T/F: After a premature heart beat, the next beat is a stronger beat due to both better filling and better contractility?

A

True

After a premature heart beat, the next beat is a stronger beat due to both better filling and better contractility

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

T/F: During diastole, IVR occurs first and atrial kick last?

A

True

During diastole, IVR occurs first and atrial kick last

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

What side/chamber of the heart is this? Labels/Characteristics?

A

Right ventricle

  • Thin outer wall and septum
  • Concave outer RV wall moves towards septum in bellows-like action allowing thin-walled RV to eject large volume against low outflow P
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the resultant circulatory change for the right ventricle? (pressure)

A

PA (pulmonary artery) pressure of 15-35 mmHg

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

Left ventricle characterized by ___ axis

A

Left ventricle characterized by long axis

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

Characteristics of LV contraction?

A
  • Decrease in chamber size and shortening of the long axis
  • Apex moves towards MV and closer to chest wall (causing PMI)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the resultant circulatory change for the left ventricle (pressure)?

A

Generate 100-120 mmHg AoP (aortic pressure) with each LV ejection

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

Where is the PMI?

A

Left MCL (mid-clavicular line) between 5th and 6th ribs

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

What are the determinants of cardiac function (5)?

A
  • Preload
  • Afterload
  • Wall stress
  • Contractility
  • Diastolic Function
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is preload? (def)

A

Blood volume in the ventricle at end-diastole

  • Preload is a key determinant of cardiac performance (CO and SV)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is Frank Starling/Starling’s Law? Graph?

A
  • Peak tension developed by muscle increases as preload increases… within physiologic limits
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the determinants of preload (4)?

A

- Intravascular volume*

- Venous return*

  • Atrial contraction
  • Pericardial function

(*most important)

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

What conditions involve increased intravascular volume (hypervolemia)?

A
  • Congestive heart failure
  • Renal failure
  • Overhydration
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What conditions involve decreased intravascular volume (hypovolemia)?

Study These Flashcards
A
  • Excessive Diuretics
  • Blood Loss
21
Q

What are the 3 main determinants of myocardial fiber shortening?

Study These Flashcards
A
  • Preload
  • Afterload
  • Contractility
22
Q

Why is fiber shortening important for cardiac function?

Study These Flashcards
A

Fiber shortening and ventricular size are key determinants of stroke volume (blood ejected with every heartbeat)

23
Q

What is afterload? (def)

Study These Flashcards
A

Tension or force acting on ventricular fibers after onset of contraction or fiber shortening

24
Q

How do changes in afterload affect cardiac function?

Study These Flashcards
A
  • BP elevation increases afterload and worsens fiber shortening and cardiac performance (SV and CO)
  • BP reduction decreases afterload and improves cardiac performance
25
What is the effect of mitral regurgitation and perceived afterload of left ventricle? Ejection fraction?
- Lower afterload (- Greater ejection fraction too, based on change in volume)
26
Increase/decrease in preload improves cardiac function?
**Increase** in preload improves cardiac function?
27
Increase/decrease in contractility improves cardiac function?
**Increase** in contractility improves cardiac function
28
Increase/decrease in afterload improves cardiac function?
**Decrease** in afterload improves cardiac function?
29
In what clinical conditions is afterload important?
- Increased afterload - Decreased afterload - Heart failure
30
Examples of **increased afterload**?
- Hypertension - Aortic stenosis We call these conditions pressure overload conditions
31
Examples of **decreased afterload**? Effect on cardiac function?
- Mitral regurgitation ("leaky" valve) - LV contracts against a lower afterload (LA) thus **cardiac performance (EF) is improved!!!**
32
What happens to cardiac function after repair of MR?
Afterload is now higher(!) as the LV has to pump blood against the aorta ONLY rather than against lower pressure LA... - Thus EF and CO worsen after MR repair
33
Which pt has higher cardiac performance? A. Normal mitral valve B. Mitral regurgitation
Which pt has higher cardiac performance? A. Normal mitral valve **B. Mitral regurgitation**
34
In heart failure, CO and EF are high/low? What happens when we reduce afterload with vasodilators?
In heart failure, CO and EF are **low** When we reduce afterload with vasodilators (ACEI), **CO and EF improve** - Vasodilators are a key part of treatment of CHF
35
Why is wall stress important?
- Wall stress affects cardiac performance (**adversely**, just like afterload) - Wall stress affects **MVO2**
36
What are the 3 main determinants of wall stress?
- P (intracavitary pressure) - R (radius) - h (wall thickness)
37
What equation is used to determine wall stress?
LaPlace Law wall stress (WS) = **PxR/2h**
38
What condition is shown here?
Eccentric hypertrophy
39
What condition is shown here?
Concentric hypertrophy
40
Which has increased wall stress? Why? Which has decreased walls tress? Why?
Increased wall stress: **left**, due to marked increase in **ventricle size** Decreased walls stress; **right**, due to marked increase in **wall thickness** (recall LaPlace's Law)
41
**Eccentric** hypertrophy is a pathophysiologic result of what?
**Volume overload** - Mitral insufficiency - Atrial septal defect
42
**Concentric** hypertrophy is a pathophysiologic result of what?
- Hypertension - Aortic stenosis
43
What is **contractility**?
Contractility and inotropic state refer to the **INHERENT** ability of muscle to contract **INDEPENDENTLY of loading** conditions
44
Contractility vs. cardiac performance?
Contractility is load-dependent, unlike cardiac performance
45
What is **positive inotropic effect**?
**Positive inotropic effect**- improvement in cardiac performance due to greater contractility in the absence of change in preload or afterload
46
What is **post-extrasystolic potentiation**?
Contraction after a pause that follows a premature beat is more forceful than normal - Greater contractility and greater preload mediates stronger beat
47
What are the 4 phases of diastole? graph
- IVR - Rapid filling - Slow filling (diastasis) - Atrial kick
48
What is **compliance**? graph
Increase in volume with little increase in pressure (shallower slope of pressure/volume curve)
49
**_Cardiac Function: Key Points_** - Contrast preload & afterload - Frank-Starling: higher preload improves performance - Three key determinants of myocardial fiber shortening: p**reload, afterload & contractility**; how do they do it? - Lower afterload in MR increases EF not contractility - LaPlace law: What are 3 determinants of wall stress? - Contrast contractility vs. cardiac performance - Define and explain post-extrasystolic potentiation
(:

_MS2 Cardio (35 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions