7. Heart Failure Flashcards
1
Q
Chronic heart failure is more prevalent in women. (T/F)
A
False: men
2
Q
What disorders cause HF?
A
- ischemic heart disease
- HTN
- valvular heart disease
- other cardiomyopathies (less freqeunt)
3
Q
Why does valvular dysfunction cause HF?
A
leaky valves over stress the heart muscle
4
Q
What is the diagnostic criteria called for HF?
A
Framingham criteria
5
Q
What are the major criteria of the Framingham criteria?
A
- nocturnal dyspnea
- neck vein distension
- pulmonary edema
- radiographic cardiomegaly
- hepatojugular reflux
6
Q
What are the minor criteria of the Framingham criteria?
A
- bilateral ankle edema
- nocturnal cough
- dyspnea on ordinary exertion
- hepatomegaly
- tachycardia
7
Q
Relaxation of the cardiac muscle cells is a passive process. (T/F)
A
False: active process
8
Q
What are the major contractile proteins?
A
- thin actin
- thick myosin
9
Q
Ca interacts with ________ to initiate muscle cell contraction.
A
troponin C
10
Q
Ca enters cardiac myocyte through __________ channels.
A
voltage sensitive L-type
11
Q
The entrance of Ca into cardiac myocyte triggers what?
A
release of Ca from sarcoplasmic reticulum
12
Q
What uncovers sites on actin that bind myosin heads?
A
tropomyosin
13
Q
What phase of the cardiac cycle occurs when the myosin heads flex?
A
systole
14
Q
What happens when Ca is removed from troponin C binding sites?
A
- ends systole
- begins the diastolic phase of cardiac cycle
15
Q
What factors strengthen muscle cell contraction?
A
- Ca concentration
- length of muscle fiber at end of diastole
16
Q
Describe the pressure difference during systole.
A
Left ventricular pressure exceeds the atrial pressure
17
Q
What valve closes during systole?
A
mitral
18
Q
During what phase of the cardiac cycle is Ca taken up by the SR?
A
diastole
19
Q
What is the preload?
A
load (blood) present before contraction
20
Q
What occurs when preload is increased?
A
- ventricle distends during diastole
- HR ↑ because atrial mechanoreceptors ↑ the rate of SA node discharge
21
Q
What is afterload?
A
systolic load on the left ventricle after it has started to contract
22
Q
Where is afterload produced?
A
in te artery leaving the ventricle
23
Q
What is the primary determinate of afterload?
A
total peripheral resistance
24
Q
Why is an increased afterload detrimental?
A
It makes the heart work harder to push the blood out into the body
25
What is end systolic volume?
Blood volume remaining in the left ventricle at the end of systole
26
What is end diastolic volume?
volume of blood in the ventricle at the end of diastole
27
How do you find stroke volume?
EDV – ESV = SV
28
What is stroke volume?
Volume of blood ejected from the ventricle during systole
29
What is ejection fraction?
The percentage of ventricular volume expelled during systole
30
Systolic HF is an impaired _______ state.
inotropic
31
What characterizes systolic HF?
- inadequate cardiac output
| - diminished expulsion of blood
32
What are the symptoms of systolic HF?
- cardiomegaly
- edema
- jugular venous distention
- left ventricular dilation
33
What is diastolic heart failure?
the reduced ability of the ventricles to accept blood
34
What characterizes diastolic HF?
- slowed or incomplete ventricular relaxation
- resting pressure in ventricle is ↑ : LV stiffness keeps the ventricle from filling properly
- SV is ↓ since filling volume is ↓
- ejection fraction may be normal
35
Left ventricular hypertrophy is greater with ______ HF.
systolic
36
Why does the heart remodel itself?
LV hypertrophy initially helps to maintain CO
37
Why is LV hypertrophy detrimental?
eventually the heart cells get so large and swollen that the contractile proteins do not overlap efficiently and over time, loses contractile function
38
Eventually, an enlarged heart cannot ____ properly and leads to _______ dysfunction.
- fill
| - diastolic
39
What is the ryanodine receptor?
Ca release channel from sarcoplasmic reticulum
40
How is Ca actively taken up into the sarcoplasmic reticulum?
SERCA: sarcoendoplasmic reticulum Ca ATPase
41
In HF, Ca uptake by _______ is depressed.
SERCA
42
Right side HF is more common than left side HF. (T/F)
False: left is more common
43
What is right side HF?
Right ventricle cannot accept or eject the returning blood volume from the periphery.
44
What is the result of right side HF?
Blood backs up into the periphery
- capillary pressure in the periphery ↑
- results in loss of fluids to the tissues
45
In right side HF, edema is in response to stimulation of the _______.
RAAS
46
What is the primary characteristic of right side HF?
peripheral edema
47
In left side HF, the right side pumps normally so blood continues to go out to the lungs. (T/F)
True
48
Left side HF results in ______ blood volume in the lungs.
increased
49
What is the pulmonary impact of left side HF?
- ↑ pulmonary capillary pressure
- fluid filters out into lung interstitial space
- pulmonary edema (serious enough to cause death)
50
What are the pulmonary symptoms of left side HF?
- dyspnea
- orthopnea
- cough from pulmonary congestion
51
What are the 3 methods that the heart may use to adapt to maintain CO?
- Frank-Starling mechanism
- activation of neurohumoral systems
- myocardial remodeling
52
What is the Frank-Starling method?
an increased preload helps to sustain cardiac performance
53
What is the activation of neurohumoral systems?
- release of norepinephrine by adrenergic cardiac nerves
| - activation of RAAS to maintain arterial pressure and perfusion to vital organs
54
What is myocardial remodeling?
mass of contractile tissue is increased
55
Which 2 cardiac adaptations occur rapidly?
- Frank-Starling mechanism
| - activation of neurohumoral systems
56
What is Starling's Law of the Heart?
Greater the heart is stretched during filling, the greater the force of contraction.
57
In a non-failing heart, an increased blood volume in, results in a normal volume pumped out. (T/F)
False: increased blood volume in, results in an increased volume pumped out
58
What is the compensation mechanism that leads to Na/water retention?
- ↓ renal perfusion
| - aldosterone release
59
What is the compensation mechanism that leads to vasoconstriction?
↑ SNS activity
↑ Ang II
↑ vasopressin
60
What is the compensation mechanism that leads to tachycardia?
- ↑ SNS activity
| - baroreceptor response to ↓ BP
61
What is the compensation mechanism that leads to ventricular hypertrophy?
↑ afterload
↓ CO
↑ preload
62
What is the compensatory benefit of Na/water retention?
↑ blood volume
| ↑ venous return, results in FS mech.
63
What is the compensatory benefit of vasoconstriction?
helps maintain BP when CO is reduced
64
What is the compensatory benefit of tachycardia?
helps maintain CO
65
What is the compensatory benefit of ventricular hypertrophy?
- helps maintain CO
| - reduced myocardial wall stress
66
What is the adverse effect of Na/water retention?
pulmonary and systemic edema
67
What is the adverse effect of vasoconstriction?
↑ afterload
| ↑ myocardial oxygen demand
68
What is the adverse effect of tachycardia?
- ↑ myocardial oxygen demand
- arrhythmias
- β1 receptor down regulation
69
What is the adverse effect of ventricular hypertrophy?
- diastolic dysfunction
- hypertrophied ventricles - valve dysfunction
- arrhythmias
70
Why is maintaining arterial pressure an effective compensatory mechanism of ↓ CO?
allows limited CO to be most useful for survival
71
In HF, where does compensatory vasoconstriction mostly occur?
areas not vital for immediate survival
- skin
- skeletal muscle
- gut
- kidney
72
What vasoconstrictor systems increase in compensatory mechanism?
- SNS
- RAAS
- endothelin
73
Redistribution of blood maintains delivery of oxygen to what organs?
brain and heart
74
What is the primary stimulus to hypertrophy?
pressure overload
75
Increased ventricular wall stress leads to:
- thickening and elongation of individual myocytes
- replication of sarcomeres
- ventricular dilation
76
With chronic volume overload, ventricle becomes more _______ and causes _____ ______ defects.
- spherical
| - mitral valve
77
A normal heart has a ______ force-frequency relationship.
positive
78
What is a positive force-frequency relationship?
the force of contraction and rate of tension development rise with ↑ stimulation frequency
79
cAMP __(↑/↓) activity of the Ca ATPase of the SERCA.
increases ↑
80
↑ Ca reuptake into the SR accelerates _______ _______.
diastolic relaxation
81
Heart failure creates a ______ force-frequecy relationship.
negative
82
In HF, disturbances in Ca concentrations __ (↑/↓) contractile function during myocardial failure.
reduce ↓
83
The Na/Ca exchanger in the cell membrane _______ Ca from the cytoplasm during diastole.
removes
84
In what way is the Na/Ca exchanger abnormal in HF?
expression is increased
85
Expression of the Na/Ca exchanger correlates ______ with the decrease in SERCA.
inversely
86
Why does Na/Ca exchanger increase as SERCA decreases?
compensatory response to the reduction in Ca reuptake by a decrease in SERCA
87
What is the benefit of increasing Na/Ca exchanger expression?
facilitates diastolic Ca removal
88
What is the adverse reaction of increasing Na/Ca exchanger expression?
increased potential for arrhythmias
89
Why does increasing Na/Ca exchanger expression increase potential for arrhythmias?
Ca efflux is associated with an influx of Na that prolongs depolarization and causes after-depolarization
90
What is NYHA Class I heart failure?
No limitation: ordinary physical activity does not cause undue fatigue, dyspnea, or palpitation
91
What is NYHA Class II heart failure?
- Slight limitation of physical activity: ordinary physical activity results in fatigue, palpitation, dyspnea, or angina
- comfortable at rest
92
What is NYHA Class III heart failure?
- Marked limitation of physical activity: less than ordinary physical activity results in symptoms
- comfortable at rest
93
What is NYHA Class IV heart failure?
- inability to carry out any physical activity without discomfort
- symptoms present at rest
