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Flashcards in Heart Failure Deck (39)
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1
Q

What is heart failure?

A

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

2
Q

Give some causes of heart failure

A

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
Q

What are the stages of heart failure?

A

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
Q

What is normal cardiac output?

A

5L/min

5
Q

What is normal stroke volume?

A

75ml

6
Q

What is the normal ejection fraction?

A

Above or equal to 50%

7
Q

What affects cardiac output?

A

Venous capacity
Heart rate
Aortic and peripheral impedance
Myocardial contractility

8
Q

What are the causes of systolic dysfunction?

A

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
Q

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

A

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
Q

Describe how the sympathetic nervous system is activated in heart failure

A

Baroreceptor mediation.

Instant response

11
Q

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

A

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

12
Q

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

A

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

13
Q

Describe briefly the renin-angiotensin-aldosterone system.

A

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
Q

What effects does AT1R activation have on the vasculature?

A

Atherosclerosis
Vasoconstriction
Vascular hypertrophy
Endothelial dysfunction

15
Q

What effects does AT1R activation have on the heart?

A

Left ventricular hypertrophy
Fibrosis
Remodelling
Apoptosis

16
Q

What effects does AT1R activation have on the kidney?

A

Decreased GFR
Increased proteinuria
Increased aldosterone release
Glomerular sclerosis

17
Q

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

A
Stroke
Hypertension
Heart failure
Myocardial infarction
Renal failure
18
Q

What are the effects of angiotensin II activation?

A
Vasoconstriction
Increased left ventricular hypertrophy and myocyte dysfunction
Increase aldosterone release
More sodium and water retention
Stimulate thirst by central activation
19
Q

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

A

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

20
Q

What causes the release of natriuretic hormones in heart failure?

A

Stretch of the arteries/veins/vasculature in the brain

21
Q

How can anti-diuretic hormone cause hyponatraemia?

A

Water is reabsorbed in excess of sodium.

Can also be due to excessive water consumption

22
Q

What is the function of endothelin?

A

Systemic and renal vasoconstriction via autocrine action, activating RAAS.

23
Q

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

A

NA

RAAS

24
Q

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

A

Vasodilate afferent renal arterioles

25
Q

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

A

NSAIDs e.g. aspirin

26
Q

What effect can alpha-TNF have in heart failure?

A

Decreases myocardial function
May stimulate NO synthase
Role in cachexia

27
Q

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

A

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
Q

How can heart failure precipitate renal failure?

A

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
Q

Who is left ventricular diastolic dysfunction most commonly seen in?

A

Elderly
Females
History of hypertension, diabetes and/or obesity

30
Q

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

A
Low left ventricular compliance
Impaired relaxation
Impaired left ventricular filling
Decreased CO
Triggers neurohormonal activation
31
Q

What are the different types of heart failure?

A
Right sided heart failure
Left sided heart failure
Biventricular (congestive) heart failure
Systolic heart failure
Diastolic heart failure
32
Q

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

A

Hypertrophy with disorganisation
or
MI which causes fibrous tissue formation

33
Q

What are the potential causes of right heart failure?

A
Chronic lung disease (most common) 
Pulmonary embolism
Pulmonary hypertension
Pulmonary/tricuspid valvular disease
ASD/VSD
Isolated right ventricular hypertrophy
34
Q

What are some symptoms of right heart failure?

A
Fatigue
Dyspnea
Anorexia
Nausea (may be due to ascites
Increased JVP
Hepatic enlargement
Ascites
Pitting oedema
Pleural effusion
35
Q

How can right heart failure precipitate a DVT?

A

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

36
Q

What are the principals of treating heart failure?

A

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

37
Q

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

A

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

38
Q

What are the pharmacological treatments for heart failure

A
Diuretics
ACEi/ARB
Nitrates
Beta blockers
Spironolactone/amiloride
Antiarrhythmics
Inotropes (only in an acute setting)
39
Q

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

A

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