CVS Session 11 Flashcards
1
Q
What is high output heart failure?
A
When the output remains the same but demand increases
2
Q
Give examples of some causes of heart failure.
A
IHD Hypertrophic cardiomyopathy Hypertension Valvular disease Dilated cardiomyopathy Arrhythmias Amyloidosis Pericardial disease
3
Q
What is the primary cause of systolic heart failure?
A
IHD
4
Q
What can cause high output heart failure?
A
A-V fistula
5
Q
What can cause dilated cardiomyopathy?
A
Alcohol/drugs/poisoning
Idiopathic
Pregnancy
Viral/bacterial/mycobacteria
6
Q
What kind of care is often needed with class IV heart failure?
A
Palliative
7
Q
Describe Class I heart failure.
A
Asymptomatic
8
Q
What class of heart failure is a patient who describes having symptoms of breathlessness on ordinary physical activity but is asymptomatic at rest?
A
II
9
Q
How do patients with Class III heart failure present?
A
Marked limitation of physical activity
Asymptomatic at rest
10
Q
Which class of heart failure do patients who are unable to carry out physical activity w/out symptoms belong?
A
IV
11
Q
Which class of heart failure patients may be symptomatic at rest?
A
IV
12
Q
What does cardiac output depend on?
A
HR
Venous capacity
Aortic and peripheral impedance
Myocardial contractility
13
Q
What is left ventricular preload?
A
Venous capacity
14
Q
What is after load?
A
Pressure needed to overcome aortic and peripheral impedance
15
Q
What is plotted on each axis to give a graph of Starling’s law of the heart?
A
X = cardiac filling/end diastolic volume Y = cardiac output
16
Q
What does Starling’s law of the heart state?
A
Force developed in a muscle fibre depends on the degree to which the fibre is stretched
17
Q
What is the average cardiac output for an adult?
A
5 litres per minute
18
Q
What is the average stroke volume for an adult?
A
75 ml per beat
19
Q
What is the average LV end systolic volume?
A
75 ml
20
Q
What is the average LV end diastolic volume?
A
150 ml
21
Q
In what range does a healthy ejection fraction lie?
A
> 50%
22
Q
Who much does the average adult heart weigh?
A
330 g
23
Q
Describe the fine line in treatment for gross heart failure.
A
Over treat with too many diuretics
Undertreat so fluid levels are too high –> congestive symptoms
24
Q
What can decrease cardiac output it becomes ineffective in a normal heart?
A
Dehydration
25
What is systolic heart failure?
Inability to effectively pump blood out of the heart
26
How does the remodelling of the heart in acute infarction and diastolic/systolic heart failure differ?
Acute - one sided due to injury
| Diastolic/systolic - same both sides
27
What happens to the left ventricular capacity in systolic dysfunction?
Increases due to thinning of myocardial wall
28
What causes mitral regurgitation in systolic dysfunction?
Valve leaflets are pulled apart due to cardiac dilation
29
What changes to the heart are seen in diastolic dysfunction?
Hypertrophy
30
What are the structural changes to the heart in heart failure?
Loss of muscle
Uncoordinated contraction
Myocardial fibre orientation slips
31
What happens to the collagen levels in the ECM of cardiac myocytes in heart failure?
Increase
| III > I
32
What is heart failure?
Clinical syndrome caused by an abnormality of the heart which means cardiac output does not meet the demand of metabolising tissues
33
What happens to myocytes in systolic dysfunction?
```
Lysis
Vacuolation
Hypertrophy
SR dysfunction
Changes the calcium availability
Changes to receptor regulation
```
34
What mediates the sympathetic nervous system?
Baroreceptors
35
What effects does activation of the sympathetic nervous system have?
Increase cardiac contractility
Arterial and venous vasoconstriction
Tachycardia
36
What long-term damaging effects does activation of the sympathetic nervous system have?
```
Down regulation of beta-adrenoceptors
Cardiac hypertrophy
Myocyte apoptosis and necrosis via alpha-receptor stimulation
Increase RAAS
Reduce HR variability
```
37
Name an anti-diuretic hormone.
Vasopressin
38
What does ADH act on?
V2 receptors in the collecting duct
39
What electrolyte state does ADH release cause?
Hyponatraemia
40
How does ADH increase cardiac output?
Causes water retention
Decreases systemic resistance
Increase HR
41
Give the products of angiotensinogen.
Angiotensinogen --> angiotensin I --> angiotensin II
42
Which receptors does angiotensin II act on?
AT1R
| AT2R
43
How does bradykinin work?
Acts on Bk2R
| Increases NO
44
What can activation of the AT1R cause?
Stroke
Hypertension
LVH
Renal failure
45
What are the effects of natriuretic hormones?
Vasodilatation
| Increased sodium excretion
46
What does natriuretic hormone stimulate upon detection of atrial and ventricular stretch?
Constriction of afferent and dilatation of efferent arterioles in kidney
47
What effect does constriction of afferent arterioles and dilatation of efferent arterioles have on kidney function?
Decreases sodium retention
Decreases renin
Decreases aldosterone
48
Where does brain natriuretic detect stretch?
Ventricles
49
Do atrial and brain natriuretic peptides have the same effects?
Yes
50
What can be measured in the blood in addition to carrying out an ECG to investigate heart failure?
Brain natriuretic hormone
51
What balances effects of RAAS on vascular tone and sodium/water balance?
Atrial and brain natriuretic hormones
52
Where is angiotensinogen released from?
Liver
Blood vessels
Brain
53
Where is the sympathetic nervous system stimulated?
Macula Rensa
54
What are the mechanisms of neuro-hormonal activation in heart failure?
```
ADH
Sympathetic nervous system
RAAS
Natriuretic hormones
Endothelin
Prostaglandin E2 and I2
Nitric oxide
Bradykinin
Alpha-TNF
```
55
What method of hormonal secretion does endothelin use?
Autocrine
56
What can be measured in the blood that correlates with the severity of heart failure?
Endothelin
| Brain natriuretic peptide
57
Where is endothelin released from?
Vascular endothelial cells
58
How does endothelin act as a renal vasoconstrictor?
Activates RAAS
59
What is stimulated by NA and RAAS to cause vasodilation on afferent renal arterioles?
Prostaglandin E1 and I2
60
Which enzyme may be blunted in heart failure which would result in a loss of vasodilation balance?
Nitric oxide synthase
61
What molecule promotes natriuresis and vasodilation and stimulates prostaglandin production?
Bradykinin
62
What are the roles of alpha-TNF in heart failure?
Depress myocardial function
May stimulate NO synthase
May have role in cachexia
63
What might cause patients with chronic heart failure to lose weight?
Too breathless to eat
Muscle wastage
Alpha-TNF causing cachexia
64
What causes skeletal muscle changes in the later stages of heart failure?
Neuro-hormonal increase in peripheral arterial resistance
65
What causes the fatigue and exercise intolerance in the later stages of heart failure?
Decreased bloodflow to all skeletal muscles incl. limbs and respiratory
66
Are there abnormalities in structure, function or both of skeletal muscle in the later stages of heart failure?
Both
67
Why does decreased cardiac output have renal effects?
Kidneys have a large requirement for blood
68
How is glomerular filtration rate maintained in early heart failure?
Haemodynamic changes at the glomerulus
69
How does a fall in GFR appear in the blood?
High serum urea and creatinine
70
What can exacerbate high serum levels of urea and creatinine?
Angiotensin II inhibitor
71
What is often confused with heart failure on diagnosis?
Anaemia - contributes to symptoms
72
What can cause anaemia in heart failure?
```
Chronic inflammatory disease (not in mild)
Expanded plasma volume
Drug therapy
Iron malabsorption
Chronic renal failure
```
73
What is a rare action of ACEI in some individuals on their bone marrow?
It is suppressed
74
What is diastolic dysfunction?
Failure of cardiac relaxation
75
Who is typically affected by diastolic dysfunction?
Elderly female w/ +ve Hx of hypertension/diabetes/obesity
76
How can left ventricle function be described in diastolic dysfunction?
Normal
77
What kind of left ventricular hypertrophy is seen in diastolic dysfunction?
Concentric
78
How does diastolic dysfunction compare to systolic dysfunction clinically?
Diagnosis less clear cut
| Hospitalisation and mortality similar
79
Describe the pathogenesis of diastolic dysfunction.
Impaired myocardial relaxation
Decreased LV compliance
Impaired diastolic LV filling
Unable to compensate by increasing LV end diastolic pressure
Decreased cardiac output --> neuro-hormonal activation
80
What is congestive heart failure?
When both sides of the heart are affected
81
What is the most common cause of right-sided heart failure?
Left heart failure
82
If right sided heart failure occurs in isolation, what is the likely cause?
Lung condition e.g. COPD, valvular disease, ASD, VSD
83
What are the S/S for right sided heart failure?
```
Fatigue
Dyspnoea
Anorexia
Nausea
Increased JVP
Tender, smooth hepatic enlargement
Pitting oedema
Ascites
Pleural effusion
```
84
What type of heart rhythm is heard in a patient with left sided heart failure?
Gallop
85
What are the S/S of mild left sided heart failure?
Fatigue
Exertional dyspnoea
Orthopnea
Paroxysmal nocturnal dyspnoea
86
What S/S are seen when LHF progresses from a mild state?
```
Tachycardia
Cardiomegaly
3rd +/- more rare 4th heart sound
Mitral regurgitation murmur
Basal pulmonary crackles
Peripheral oedema
```
87
What is the first stage in heart failure management?
Correct underlying cause
88
What lifestyle modifications can be made to manage heart failure?
Decrease salt, alcohol and BP
| More aerobic exercise
89
What classes of drugs can be used to improve the symptoms of heart failure?
Diuretics
Beta-blockers
Anti-arrhythmics
90
What treatment can be used to inhibit rennin systems in order to delay the progression of heart failure if ACEI are not tolerated?
Nitrates
91
How does a biventricular pacemaker work?
Increase biventricular heart contraction coordination to increase cardiac output (heart still failing but CO sufficient)
92
How do implantable defibrillators work?
Pace quickly or deliver shock to heart to restore normal rhythm
93
Why can ACEI cause a dry cough?
Increase bradykinin levels in the lungs
94
What is a common cause for using angiotensin II receptor antagonists instead of ACEI to treat heart failure?
Dry cough
