19. Pathophysiology of Heart Failure

Question 1

Define Heart Failure

Answer 1

Syndrome that arises when the heart is unable to maintain an appropriate blood pressure without support

Question 2

Definition of heart failure in Man

Answer 2

A clinical syndrome caused by an abnormality of the heart and recognised by a characteristic pattern of haemodynamic, renal, neural and hormonal responses

Question 3

When heart failure occurs what other organ failure also occurs?

Answer 3

Kidney failure because they won’t be perfused enough

Question 4

How much cardiac output do kidneys receive?

Answer 4

Kidneys receive 35-40% of cardiac output

Question 5

List the causes of heart failure

Answer 5

Arrhythmias
Valve Disease
Pericardial Disease
Congenital Heart Disease
Myocardial Disease

Question 6

What are Arrhythmias?

Answer 6

Irregular heart beat - mainly tachycardias

Question 7

What are valve diseases?

Answer 7

mitral or aortic regurgitation or valve stenoses

Question 8

What are pericardial diseases?

Answer 8

If the pericardium becomes inflamed and fibrotic then the heart can’t relax and pump as well

Question 9

What is congenital heart disease?

Answer 9

If there are holes or misconnections then there is an increased risk of heart failure

Question 10

What is the commonest cause of myocardial disease?

Answer 10

coronary heart disease

Question 11

Types of cardiomyopathy?

Answer 11

• Dilated Cardiomyopathy (DCM) - specific or idiopathic
• Hypertrophic Cardiomyopathy (HCM or HOCM or ASH)
• Restrictive Cardiomyopathy
• Arrhythmic Right Ventricular Cardiomyopathy (ARVC)

Question 12

List some examples of myocardial disease?

Answer 12

Cardiomyopathy
HOCM = Hypertrophic obstructive cardiomyopathy
ASH = Asymmetrical Septal Hypertrophy
Hypertension

Question 13

What drugs can cause heart failure?

Answer 13

Overdosing on beta blockers - it can decrease heart rate so much you get heart failure
Anti-arrhythmics - cause dysfunction of the heart
Calcium antagonists

Question 14

What is myocardial remodelling

Answer 14

When there is part of a heart that is thin and fibrotic so that when the heart contracts the fibrous tissue just expands - infarct expansion. In order to maintain normal pump activity the heart remodels itself.

Question 15

How does part of the heart tissue become thing and fibrotic?

Answer 15

When an infarction has happened in that area

Question 16

Define cardiomyopathy

Answer 16

Heart disease in the absence of a known cause

Question 17

What is the most common cause of young athletes dropping dead?

Answer 17

Hypertrophic cardiomyopathy

Question 18

Define dilated cardiomyopathy

Answer 18

The heart’s ability to pump blood is decreased because the left ventricle, is enlarged and weakened.

Question 19

List an infectious cause of dilated cardiomyopathy?

Answer 19

Viruses such as HIV

Question 20

What are the toxins and poisonous causes of dilated cardiomyopathy?

Answer 20

Ethanol and cocaine

Question 21

What drugs can cause dilated cardiomyopathy?

Answer 21

Chemotherapeutic agents and antiviral agents

Question 22

Define restrictive cardiomyopathy

Answer 22

The heart is restricted so can’t dilate normally. The ejection fraction is preserved by there is diastolic dysfunction so it’s slow in relaxing

Question 23

What is restrictive cardiomyopathy associated with?

Answer 23

Fibrosis, hypertrophy and scleroderma

Question 24

What is a common symptom of restrictive cardiomyopathy?

Answer 24

The patients will often be short of breath

Question 25

What infiltrative disorders are associated with restrictive cardiomyopathy?

Answer 25

Amyloidosis and sarcoidosis

Question 26

Define infiltrative disorders

Answer 26

Where there is infiltration of amyloid proteins and granulocytes into the heart muscle which impairs heart function

Question 27

What are the hormonal mediators in heart failure

Answer 27

Constrictors, dilators and growth factor

Question 28

During heart failure what hormone is increased?

Answer 28

Because the body things it is bleeding to death there is an increase in adrenaline, nor adrenaline and the sympathetic drive is switched on

Question 29

During heart failure what organ tries to increase blood pressure?

Answer 29

The kidney as it tries to retain salt and water so the RAS system is switched.

Question 30

What vasoconstrictors are produced in response to heart failure?

Answer 30

Endothelin-1, vassopressin and neuropeptide Y in the endothelial cells

Question 31

What peptide is checked when diagnosing heart failure?

Answer 31

Atrial natriuretic peptide (ANP) High = impaired heart Troponin I and T levels are also increase in heart failure

Question 32

What are the inflammatory markers and cytokines in heart failure specific to the heart?

Answer 32

Troponin T and Troponin I

Question 33

What are the inflammatory markers and cytokines in heart failure specific to the vessel wall?

Answer 33

ICAM-1 VCAM-1 E-selectin P-selectin

Question 34

With heart failure what is the 5 year mortality rate?

Answer 34

50%

Question 35

What is the median survival time following diagnosis of heart failure?

Answer 35

``` Men = 1.7 years Women = 3.2 years ```

Question 36

What is most common symptom of heart failure

Answer 36

Fatigue - tiredness

Question 37

What is orthopnoea?

Answer 37

Breathlessness when lying down. Where is a slight decrease in pressure in the atria when patients are propped up making it easier for the heart to function

Question 38

What is PND?

Answer 38

Paroxysmal Nocturnal Dysopnoea - they start sleeping propped up and then slip down, they wake up gasping for air so they have to get up and go to the window for air - this is a sign of severe heart failure

Question 39

How does heart failure affect heart rate and pulses?

Answer 39

Patients may have an increased heart rate to maintain cardiac output and have weak pulses

Question 40

How does heart failure affect venous pressure?

Answer 40

Patients have increased venous pressure due to the elevated pressures in the right side of the heart

Question 41

How does salt and water retention caused by heart failure affect the body?

Answer 41

Peripheral oedema

Question 42

How does heart failure affect the liver and abdomen?

Answer 42

Hepatomegaly and ascites

Question 43

What can be seen on heart failure chest X-ray?

Answer 43

Increase in the cardio-thoracic ratio.

Question 44

What should the cardio-thoracic ratio be on a normal chest X-ray?

Answer 44

In normal people the width of the heart should not be more than 50% of the width of the thorax

Question 45

What is the reason for using the New York Heart association classification of functional capcity?

Answer 45

So you can tell whether a patient has improved after treatment

Question 46

List the classes and describe them?

Answer 46

``` 1 = virtually no symptoms - the heart is dysfunctioning but most things are fine 2 = slight limitation of physical activity 3 = marked limitation of physical activity 4 = the patient can’t get out of a chair or is in bed ```

Question 47

Describe the progression of heart failure?

Answer 47

There is a plateau and then it suddenly drops off. The last downwards section can happen in a matter of weeks or months

Question 48

What are the syndromes of heart failure?

Answer 48

Acute Heart Failure - Associated with pulmonary oedema Circulatory Shock - Associated with cardiogenic shock (poor peripheral perfusion, oliguria, hypotension) Chronic Heart Failure - Untreated, congestive, undulatinf, treated, compensated

Question 49

How will the patient look if there is a blockage of the coronary artery and the heart muscle dies?

Answer 49

They will look very sick, tachycardic, sweating, sitting upright in bed, very breathless, coughing up frothy sputum

Question 50

How do you treat pulmonary oedema?

Answer 50

Give diuretics to get rid of the fluid in the lungs

Question 51

What are the key investigations during heart failure?

Answer 51

ECG Coronary Angiography - can show where there is a stricture 2D echocardiogram - you can see have the heart is actually pumping MRI scanning

Question 52

What is the management algorithm for heart failure?

Answer 52

1. Establish that patient has heart failure 2. Determine aetiology of heart failure 3. Identify concomitant disease relevant to heart failure 4. Assess severity of symptoms 5. Predict prognosis 6. Anticipate complications 7. Choose appropriate treatment 8. Monitor progress and tailor treatment

Question 53

List the common drugs used for heart failure

Answer 53

Diuretics Ace Inhibitors Beta Blockers Aldosterone Antagonists (Spironolactone) Digoxin (for atrial fibrillation) Devices (cardiac resynchronisatioin, implanted cardioverter defibrillator)