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Flashcards in Heart Failure Deck (39):
1

What is heart failure?

The state in which the heart fails to maintain an adequate circulation for the needs of the body despite an adequate pressure.

2

Give some causes of heart failure

Ischaemic heart disease
Hypertension
Dilated cardiomyopathy
High output heart failure - AV fistula or Paget's disease (extra blood vessels)
Arrhythmia
Restrictive cardiomyopathy e.g. amyloidosis
Valvular/congenital heart disease

3

What are the stages of heart failure?

I - no symptomatic limitations
II - slight limitations to physical activity, no symptoms at rest
III - limitations with less than normal activity. No symptoms at rest.
IV - can't carry out physical activity without symptoms. May also have symptoms.

4

What is normal cardiac output?

5L/min

5

What is normal stroke volume?

75ml

6

What is the normal ejection fraction?

Above or equal to 50%

7

What affects cardiac output?

Venous capacity
Heart rate
Aortic and peripheral impedance
Myocardial contractility

8

What are the causes of systolic dysfunction?

Increased left ventricular dysfunction
Decreased left ventricular cardiac output
Thinning of the myocardial wall (fibrosis and necrosis, activity of matrix proteinases)
Mitral valve incompetence
Neural-hormonal inactivity
Cardiac arrhythmia

9

What structural changes can be seen in the heart in heart failure?

Reduced muscle
Uncoordinated or abnormal myocardial contraction
Changes to the ECM (increased collagen/slippage of fibre orientation )
Change in cellular structure and function (myocytolysis/vacuolation)
Myocyte hypertrophy
SR dysfunction
Change to calcium availability
Receptor regulation

10

Describe how the sympathetic nervous system is activated in heart failure

Baroreceptor mediation.
Instant response

11

What is the positive short term effect of sympathetic nervous system activation in heart failure

Increases cardiac output by improving contractility, arterial/venous contraction and causing tachycardia.

12

What are the long term negative effects of sympathetic nervous system activation in heart failure?

Beta-adrenergic receptors downregulated or uncoupled
Noradrenaline increases cardiac hypertrophy and triggers myocyte apoptosis/necrosis via alpha-receptors
Induce upregulation of RAAS

13

Describe briefly the renin-angiotensin-aldosterone system.

Angiotensinogen to angiotensin I by renin
Angiotensin I to angiotensin II by ACE
AT1R is detrimental
AT2R causes water retention and aldosterone secretion, increases NO production.

14

What effects does AT1R activation have on the vasculature?

Atherosclerosis
Vasoconstriction
Vascular hypertrophy
Endothelial dysfunction

15

What effects does AT1R activation have on the heart?

Left ventricular hypertrophy
Fibrosis
Remodelling
Apoptosis

16

What effects does AT1R activation have on the kidney?

Decreased GFR
Increased proteinuria
Increased aldosterone release
Glomerular sclerosis

17

What clinical problems can be caused by AT1R activation in the long term?

Stroke
Hypertension
Heart failure
Myocardial infarction
Renal failure

18

What are the effects of angiotensin II activation?

Vasoconstriction
Increased left ventricular hypertrophy and myocyte dysfunction
Increase aldosterone release
More sodium and water retention
Stimulate thirst by central activation

19

What is the function of natriuretic hormones activated in heart failure?

Decreases sodium reabsorption
Inhibits secretion of renin and angiotensin
Balance the effects of RAAS on vascular tone and sodium/water balance

20

What causes the release of natriuretic hormones in heart failure?

Stretch of the arteries/veins/vasculature in the brain

21

How can anti-diuretic hormone cause hyponatraemia?

Water is reabsorbed in excess of sodium.
Can also be due to excessive water consumption

22

What is the function of endothelin?

Systemic and renal vasoconstriction via autocrine action, activating RAAS.

23

What stimulates the release of prostaglandin E2/I2 in heart failure?

NA
RAAS

24

What is the function of prostaglandin E2/I2 in heart failure?

Vasodilate afferent renal arterioles

25

What drugs can block the action of prostaglandin E2/I2?

NSAIDs e.g. aspirin

26

What effect can alpha-TNF have in heart failure?

Decreases myocardial function
May stimulate NO synthase
Role in cachexia

27

How does changes to vascular tone exacerbate the clinical features of heart failure?

Decreased skeletal muscle tone
Decreased skeletal muscle mass including the limbs and respiratory muscles (can cause death)
Abnormal structure and function
Fatigue and exercise intolerance

28

How can heart failure precipitate renal failure?

GFR initially maintained by haemodynamic changes in the glomerulus
Increased sodium/water retention. Neurohormonal action.
Decreased GFR in severe heart failure which causes increased serum urea and creatinine
Can be exacerbated by treatment which inhibits angiotensin II

29

Who is left ventricular diastolic dysfunction most commonly seen in?

Elderly
Females
History of hypertension, diabetes and/or obesity

30

What are the problems in the heart when there is left ventricular diastolic dysfunction?

Low left ventricular compliance
Impaired relaxation
Impaired left ventricular filling
Decreased CO
Triggers neurohormonal activation

31

What are the different types of heart failure?

Right sided heart failure
Left sided heart failure
Biventricular (congestive) heart failure
Systolic heart failure
Diastolic heart failure

32

How can diastolic heart failure be caused by systolic heart failure?

Hypertrophy with disorganisation
or
MI which causes fibrous tissue formation

33

What are the potential causes of right heart failure?

Chronic lung disease (most common)
Pulmonary embolism
Pulmonary hypertension
Pulmonary/tricuspid valvular disease
ASD/VSD
Isolated right ventricular hypertrophy

34

What are some symptoms of right heart failure?

Fatigue
Dyspnea
Anorexia
Nausea (may be due to ascites
Increased JVP
Hepatic enlargement
Ascites
Pitting oedema
Pleural effusion

35

How can right heart failure precipitate a DVT?

Systemic congestion which increases stasis in the veins and therefore increases the risk of a DVT

36

What are the principals of treating heart failure?

Correct the underlying cause
Pharmacological treatments
Non-pharmacological treatments
Treat complications, associated conditions and cardiovascular risk factors.

37

What lifestyle modifications could you suggest to someone with heart failure?

Reduce salt intake
Decrease alcohol intake
Increase aerobic exercise
Decrease blood pressure

38

What are the pharmacological treatments for heart failure

Diuretics
ACEi/ARB
Nitrates
Beta blockers
Spironolactone/amiloride
Antiarrhythmics
Inotropes (only in an acute setting)

39

Suggest a form of cardiac surgery which can be used to treat heart failure

Total heart transplantation
Mechanical assist devices
Underlying cause - valve surgery/revascularisation
Implantable pacemakers/defibrillator