CVS Session 11 Flashcards Preview

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Flashcards in CVS Session 11 Deck (94):
1

What is high output heart failure?

When the output remains the same but demand increases

2

Give examples of some causes of heart failure.

IHD
Hypertrophic cardiomyopathy
Hypertension
Valvular disease
Dilated cardiomyopathy
Arrhythmias
Amyloidosis
Pericardial disease

3

What is the primary cause of systolic heart failure?

IHD

4

What can cause high output heart failure?

A-V fistula

5

What can cause dilated cardiomyopathy?

Alcohol/drugs/poisoning
Idiopathic
Pregnancy
Viral/bacterial/mycobacteria

6

What kind of care is often needed with class IV heart failure?

Palliative

7

Describe Class I heart failure.

Asymptomatic

8

What class of heart failure is a patient who describes having symptoms of breathlessness on ordinary physical activity but is asymptomatic at rest?

II

9

How do patients with Class III heart failure present?

Marked limitation of physical activity
Asymptomatic at rest

10

Which class of heart failure do patients who are unable to carry out physical activity w/out symptoms belong?

IV

11

Which class of heart failure patients may be symptomatic at rest?

IV

12

What does cardiac output depend on?

HR
Venous capacity
Aortic and peripheral impedance
Myocardial contractility

13

What is left ventricular preload?

Venous capacity

14

What is after load?

Pressure needed to overcome aortic and peripheral impedance

15

What is plotted on each axis to give a graph of Starling's law of the heart?

X = cardiac filling/end diastolic volume
Y = cardiac output

16

What does Starling's law of the heart state?

Force developed in a muscle fibre depends on the degree to which the fibre is stretched

17

What is the average cardiac output for an adult?

5 litres per minute

18

What is the average stroke volume for an adult?

75 ml per beat

19

What is the average LV end systolic volume?

75 ml

20

What is the average LV end diastolic volume?

150 ml

21

In what range does a healthy ejection fraction lie?

>50%

22

Who much does the average adult heart weigh?

330 g

23

Describe the fine line in treatment for gross heart failure.

Over treat with too many diuretics
Undertreat so fluid levels are too high --> congestive symptoms

24

What can decrease cardiac output it becomes ineffective in a normal heart?

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