Chronic Heart Failure

Question 1

Define Heart Failure

Answer 1

Failure of the heart as a pump to meet the circulatory needs

Question 2

What are the two components of the heart that may fail?

Answer 2

Heart Muscle

Heart Valves

Question 3

What are the two main classifications of Heart Failure?

Answer 3

Chronic

Acute

Question 4

What are the most common causes of Heart Failure?

Answer 4

Hypertension (hypertrophy, increased cardiac work)
IHD (impaired muscle)
Cardiomyopathies (alcohol, viral)

Question 5

What factors may precipitate Heart Failure?

Answer 5

Pregnancy
Anaemia
Hyper-/Hypo-thyroidism
Fluid retaining drugs (NSAIDs, glucocorticoids)

Question 6

What are the four neurohormonal responses as a compensation for circulatory failure?

Answer 6

Activation of SNS
Activation of RAAS
Activation of ADH (Anti Diuretic Hormone)
Activation of ANP (Atrial Natriuretic Protein)

Question 7

What are the effects of neurohormonal adaptation?

Answer 7

Increased afterload
Increased circulating volume
Increased resistance - impaired renal func - salt/water retention - activation of RAAS
MYOCYTE DYSFUNCTION

Question 8

Describe Left-Sided Heart Failure

Answer 8

Impairment of LV (poor output) leading to increased LA/pulmonary venous pressure (pulmonary oedema)
Secondary to hypertension

Question 9

Describe Right-Sided Heart Failure

Answer 9

Impairment of RV (poor output) leading to increased RA pressure
Secondary to lung disease (cor pulmonale) or pulmonary valvular stenosis

Question 10

Describe Biventricular Failure

Answer 10

Impairment of both chambers
Can be due to IHD of both ventricles
LVF leads to pulmonary congestion, can lead to RVF

Question 11

What are the signs/symptoms of Heart Failure?

Answer 11

Fatigue
Poor exercise tolerance (grading)
Cold peripheries
Low BP
Reduced urine
Weight loss

Question 12

What signs/symptoms are specific to LVF?

Answer 12

Pulmonary Oedema

• Dyspnoea w/ sensation of drowning
• Orthopnoea
• Cough
• Inspiratory crepitations

Question 13

What signs/symptoms are specific to RVF?

Answer 13

Raised venous pressure
Increased JVP
Enlarged liver
Peripheral oedema

Question 14

What diagnostic signs are needed to confirm a diagnosis of Heart Failure?

Answer 14

Ejection Fraction <45% (echocardiogram)

BNP levels

Question 15

What signs of Heart Failure are present on a CXR?

Answer 15

Cardiomegaly
Pulmonary oedema
Kerley’s lines (lymphatic distension)

Question 16

What is Atrial Fibrillation?

Answer 16

A condition where the LA has multiple pacemaker signals

An abnormal heart rate characterised by rapid and irregular beating

Question 17

What is the most common cause of Atrial Fibrillation?

Answer 17

LV/valve failure - increased LA pressure - distension - Atrial Fibrillation

Question 18

What is the major risk with Atrial Fibrillation?

Answer 18

Stasis of blood - thrombi formation - risk of TIA

Question 19

How should Atrial Fibrillation be treated prophylactically?

Answer 19

Prophylaxis against thromboembolism

Warfarin/Aspirin

Question 20

What are the main goals when treating Heart Failure?

Answer 20

Treat any cause
Reduce cardiac workload
Increase cardiac output
Counteract maladaptation
Relieve symptoms
Prolong quality life

Question 21

How is pharmacological management for Heart Failure decided?

Answer 21

Stage dependent

Question 22

What should patients with Left Ventricular Systolic Dysfunction be treated with?

Answer 22

ACEIs

Question 23

What should patients with Oedema be treated with?

Answer 23

Diuretics

Question 24

What should patients with moderate/stable Heart Failure be treated with?

Answer 24

Beta-Blockers

Question 25

Why are ACEIs effective in LVSD?

Answer 25

Reduce arterial/venous vasocoonstriction Reduce salt/water retention Inhibit RAAS system (oppose neurohormonal adaptation)

Question 26

Give several examples of ACEIs

Answer 26

Ramipril, Lisinopril, Enalapril

Question 27

How should ACEI dosing be controlled?

Answer 27

Start with a low dose then titrate up

Question 28

What drug class should ACEIs not be used with?

Answer 28

NSAIDs

Question 29

What should be monitored before and during treatment with ACEIs?

Answer 29

Urea/Creatinine | K+

Question 30

When should ACEIs be avoided?

Answer 30

Hypotension (<100mg sys) | Renal failure

Question 31

What are the most common problems with ACEIs?

Answer 31

Severe hypotension Cause renal damage Hyperkalaemia

Question 32

How do ATRAs work?

Answer 32

Oppose actions of AII at the AT1 receptor

Question 33

Give examples of ATRAs

Answer 33

Candesartan Valsartan Losartan

Question 34

When are diuretics used to treat Heart Failure?

Answer 34

When oedema is present

Question 35

What sort of diuretics are used to treat Heart Failure?

Answer 35

``` Thiazides (bendroflumethiazide) - mild failure/elderly Loop Diuretics (Furosemide) - pulmonary oedema ```

Question 36

How do diuretics work?

Answer 36

Reduction in circulating volume Reduce pre-/after-load Venodilation

Question 37

What is the major problem with diuretics?

Answer 37

May cause hypokalaemia

Question 38

When are Beta-Blockers used to treat Heat Failure?

Answer 38

Stable/moderate failure | Esp. useful when associated with Ischaemia

Question 39

How do Beta-Blockers work?

Answer 39

Reduce sympathetic stimulation/hear rate/O2 use Antiarrhythmic Oppose neurohormonal activation

Question 40

How should Beta-Blocker dosing be controlled?

Answer 40

Start with low dose and increase

Question 41

What may be the immediate response to treatment with Beta-Blockers?

Answer 41

Symptoms may get worse at first

Question 42

What is Spironolactone?

Answer 42

Aldosterone receptor antagonist

Question 43

How is Spronolactone used?

Answer 43

Reverses left ventricular hypertrophy | Inhibits effects of aldosterone on heart (ie. fibrosis)

Question 44

What is Digoxin?

Answer 44

Positive inotrope causing heart block and bradycardia

Question 45

How does Digoxin work?

Answer 45

Inhibits Na+/K+ ATPase Na accumulates - exchanged with Ca INCREASED CONTRACTILITY Impairs AV conduction, increases vagal activity

Question 46

When is Digoxin used to treat Heart Failure?

Answer 46

Heart failure with atrial fibrillation

Question 47

How should Digoxin dosing be controlled?

Answer 47

Titrate dose, ensure ventricular rate doesn't fall below 60BPM

Question 48

What drugs are contraindicated in renal failure?

Answer 48

Thiazides - ineffective | ACEIs - impair renal function

Question 49

Why should Potassium be monitored during treatment?

Answer 49

Thiazides/Loop Diuretics cause Hypokalaemia Enhances effect of Digoxin ACEIs w/ K+ sparing diuretic causes Hyperkalaemia

Question 50

Describe Digoxin toxicity?

Answer 50

Narrow therapeutic window Anorexia, nausea, visual disturbances, diarrhoea Pulse <60BPM