Cardiac Failure

Question 1

What is cardiac failure?

Answer 1

Cardiac output less than body needs

Question 2

What is the normal cardiac output?

Answer 2

5-6 L/min

Question 3

What is the normal stroke volume?

Answer 3

70 ml/beat

Question 4

What is high output cardiac failure?

Answer 4

Failure due to increased body needs
- Anaemia
- Severe aortic regurgitation
- Thyrotoxicosis
- Fever
- AV fistulae
Rare

Question 5

What is usually reduced in cardiac failure: systolic or diastolic function?

Answer 5

Systolic - low ejection fraction

Question 6

At what ejection fraction do you usually get symptoms of cardiac failure at?

Answer 6

30-40%

Question 7

What is the ejection fraction in stiff diastolic function causing cardiac failure?

Answer 7

Normal

Question 8

What is preload?

Answer 8

Venous return

Question 9

What is contractility?

Answer 9

Strength of pump

Question 10

What is afterload?

Answer 10

Resistance against which heart must pump

Question 11

Why should you check the JVP before giving a cardiac failure patient fluid for low blood pressure?

Answer 11

Danger in giving a person with high preload more fluid

Question 12

How can preload be clinically determined?

Answer 12

Right heart: JVP

Left heart: pulmonary venous pressure = PA wedge pressure

Question 13

What does an increase in venous pressure mean?

Answer 13

Fluid leaks out

Oedema

Question 14

What are some signs of right heart failure?

Answer 14

High JVP
Peripheral oedema
Hepatic congestion

Question 15

What are the causes of oedema?

Answer 15

Increased venous pressure
Decreased osmotic pressure
Blocked lymphatics
Increased capillary permeability

Question 16

What can cause a decreased osmotic pressure?

Answer 16

Plasma protein loss

• Renal failure
• Liver failure

Question 17

What can block lymphatics?

Answer 17

Cancer

Question 18

What can cause increased capillary permeability?

Answer 18

Infection

Question 19

Where is the oedema if there is increased pulmonary venous pressure, affecting the left atrium?

Answer 19

Pulmonary congestioon

Pulmonary oedema

Question 20

Where is the oedema if there is increased systemic venous pressure, affecting the right atrium?

Answer 20

Peripheral congestion

Peripheral oedema

Question 21

Why and how is preload increased in cardiac failure?

Answer 21

Decreased contractility > decreased cardiac output

To bring cardiac output to normal > Na and fluid retention

Question 22

What is the mechanism for fluid retention in cardiac failure?

Answer 22

Decreased cardiac output > decreased renal blood flow > activation of renin-angiotensin-aldosterone system (RAAS) >

• Fluid and Na retention
• K loss
• Vasoconstriction

Question 23

What does the sympathetic nervous system do in cardiac failure?

Answer 23

Increased noradrenaline
Initial increased contractility
Long-term deleterious effects
- Vasoconstriction
- Ventricular arrhythmias
- Direct toxic effect

Question 24

What does it mean if you find both swollen ankles and sacral oedema?

Answer 24

Like paroxysmal nocturnal dyspnoea (PND) is to orthopnea - need to be admitted to hospital for treatment

Question 25

Why is orthopnoea specific for cardiac failure?

Answer 25

When standing most of fluid in lower part of lungs, so able to use upper part of lungs When lying down, more alveoli involved For other causes of shortness of breath, there is no effect of gravity on lungs

Question 26

What are the examination findings for cardiac failure?

Answer 26

Crackles on chest examination - Could be cardiac/respiratory cause - If respiratory, may improve on coughing JVP elevated - Indicates high right atrial pressure, and thus, right ventricular end diastolic pressure - Often correlates with high left atrial pressure Oedema

Question 27

What are the investigations for cardiac failure?

Answer 27

``` CXR - Heart size > make sure using erect PA film - Lung fields, looking for - Pleural effusion - Kerley B lines - Perihilar batwing shadowing - Fluffy alveoli Echocardiogram - Chamber size and function - Valves - Structure ```

Question 28

What are the causes of cardiac failure?

Answer 28

``` Ischaemic heart disease: MI - Vast majority of cases Valvular heart disease - Common Hypertension Congenital heart disease Cardiomyopathy Cor pulmonale Pericardial disease; eg: Coxsackie virus ```

Question 29

Can the JVP be elevated but the pulmonary venous pressure be normal?

Answer 29

In pure right heart failure | Rare

Question 30

What are the causes of right heart failure?

Answer 30

``` Pulmonary hypertension - Cor pulmonale - Pulmonary embolism Right sided structural disease - Pulmonary/tricuspid valves - Right ventricular cardiomyopathy Pericardial disease ```

Question 31

What is cor pulmonale?

Answer 31

Heart failure due to lung diseases?

Question 32

What lung diseases can cause cor pulmonale?

Answer 32

COPD Cystic fibrosis Pulmonary fibrosis

Question 33

What is the cardinal symptom of left heart failure?

Answer 33

Shortness of breath

Question 34

What is the cardinal sign of left heart failure?

Answer 34

Lung crepitations

Question 35

What is the classification of left heart failure based on ejection fractions?

Answer 35

Mild = 40-50% Moderate = 30-40% Severe <30%

Question 36

What are the possible causes of diastolic heart failure?

Answer 36

Stiff ventricle - poor compliance - Infarct-related scar - Chronic hypertension - Ventricular hypertrophy

Question 37

What are the principles of treatment for heart failure?

Answer 37

Reduce venous pressure - Relieves congestion and oedema - But without reducing cardiac output too much Block RAAS - Produces long-term fluid loss and vasodilatation Block sympathetic nervous system - Block direct cardiac toxic effects of beta stimulation Treat underlying and precipitating causes

Question 38

What are the medications used in the treatment of cardiac failure?

Answer 38

Duiretics; eg: frusemide Aldosterone antagonists; eg: spironolactone ACE inhibitors and/or angiotensin receptor antagonists (ARBs) Beta blockers - Use cardioselective if possible

Question 39

What additional treatment is there available for cardiac failure?

Answer 39

Biventricular pacing - Improves cardiac function Implantable cardioverter defibrillator - Because ventricular arrhythmias and sudden death common in heart failure Cardiac assist devices and transplantations - For small group who don't respond to other treatment - Not usually appropriate for elderly patients