Lecture 5 LV Dysfunction and Heart Failure I

Question 1

What is the NICE definition of heart failure

Answer 1

A complex clinical syndrome of symptoms and signs that suggest the efficiency of the heart as a pump is impaired

Question 2

What is the ESC definition of heart failure

Answer 2

An abnormality of cardiac structure or function which leads to failure of the heart to deliver oxygen at a rate commensurate with the requirement of the tissues despite normal filling pressures or only at the expense of increased filling pressures

Question 3

How many patients per year in the UK experience heart failure

Answer 3

1 million

Question 4

Heart failure will increase in incidence by 50% in the next 5 years T or F

Answer 4

T

Question 5

What is the main risk factor of heart failure

Answer 5

Age – heart failure is a disease of ageing it is rare below 65 but extremely common in the over 85

Question 6

Why is it thought that heart disease affects more men than women

Answer 6

Most likely underlying coronary artery disease which is more prevalent in males

Question 7

What percentage of hospital admissions is accounted for by heart failure

Answer 7

5%

Question 8

Heart failure accounts for 2% of the NHS budget. Where is most of this cost incurred

Answer 8

70% of heart failures cost to the NHS is on hospital admission

Question 9

What is the prognosis of heart failure

Answer 9

Heart failure prognosis is extremely poor with an overage 30% mortality within 1 year

Question 10

What causes the majority of heart failure

Answer 10

Left ventricular systolic dysfunction (LVSD)

Question 11

Other than LVSD what other category of heart failure is there

Answer 11

Heart failure with preserved ejection fraction (HFPEF)

Question 12

How can problems with diastole cause heart failure

Answer 12

Relaxation of the heart in diastole isn’t passive it’s an active energy dependent process requiring ATP. Thus patients can have problems with this and hence have heart failure with preserved ejection fraction

Question 13

How can we classify heart failure based on its onset

Answer 13

Acute heart failure is when a patient suddenly deteriorates whereas chronic heart failure is a creeping worsening state that gradually gets worse over time

Question 14

Give an example of a structural cause of heart failure

Answer 14

Mitral valve rupture can sometimes cause heart failure

Question 15

What is the most common cause of heart failure

Answer 15

Coronary artery disease

Question 16

Discuss why treatments of heart failure don’t target the heart itself

Answer 16

Drugs that stimulate the heart when its poorly contracting increase the energy requirements by the heart. When a patient is in heart failure a neurohumoral response triggered in response to decreased cardiac output this is an attempt to support the circulation. However this response can be derogatory and increased the demands of the heart. So instead treatments are therefore aimed at the response not at the heart itself.

Question 17

What is the main target in heart failure treatment

Answer 17

The main approach is a vasodilator therapy that acts via neurohormonal blockade. This includes blocking the renin-angiotensin-aldosterone system and the sympathetic nervous system.

Question 18

What is the difference between left ventricular dysfunction and heart failure

Answer 18

LV dysfunction is something you can measure by measuring the ejection fraction whereas heart failure is the clinical syndrome observed

Question 19

What are the two broad effects of heart failure

Answer 19

Reduced cardiac output and increased filling pressures/preload

Question 20

What causes reduced cardiac output in patients in heart failure and how does this present

Answer 20

Reduced cardiac output is often due to decreased ejection fraction. Patients will present with fatigue and exercise intolerance

Question 21

What causes the increased filling pressures/preload in heart failure

Answer 21

There is an increased back pressure upstream of the ventricles because the ventricles aren’t clearing as much blood. This means that the veins leading to the ventricles increase in pressure

Question 22

What symptom is associated specifically with LVSD in heart failure

Answer 22

Pulmonary oedema due to increased pressure in the left atria backtracking to the pulmonary veins subsequently increasing pressure in those vessels. This causes fluid to leave the vessels and enter the lungs

Question 23

How do patients with pulmonary oedema usually present

Answer 23

Patients are extremely uncomfortable and want to be sat up in order to decrease pulmonary pressure an used all respiratory muscles

Question 24

What is the dominant symptom in patients with heart failure and how does this present

Answer 24

The dominant symptom is venous congestion which presents as breathlessness during minor exertion

Question 25

What symptom is associated specifically with right ventricular dysfunction in heart failure and how does this present

Answer 25

Peripheral oedema due to increased pressure in the right atria backtracking to the all of the veins. This presents as swelling of the lower limbs and abdomen (Ascites)

Question 26

What is meant by anasarca

Answer 26

‘Michelin man effect’ where oedema has travelled far up the body

Question 27

Why is the increase in filling pressure that occurs in heart failure as a result of the ventricles diminished ability to clear blood of little benefit to patients

Answer 27

The steepness of the Frank-Starling curve is much shallower in these patients so therefore increases in preload/filling pressures wont increase cardiac output by any significant amount

Question 28

What is synonymous with preload

Answer 28

Filling pressure left ventricular end diastolic pressure end diastolic volume

Question 29

Diuretics and venodilators can cause hypotension in healthy patients why does this often not occur in patients in heart failure

Answer 29

Due to the much shallower Frank-Starling curve these drugs can shift patients out of pulmonary congestion with very little loss of cardiac output

Question 30

What are the main broad effects of diuretics

Answer 30

Cause the body to lose Na+ and water

Question 31

What are the main clinical indications for diuretics

Answer 31

Heart failure hypertension

Question 32

What are the 4 main classes of diuretics

Answer 32

Thiazide diuretics loop diuretics K+ sparing diuretics and aldosterone antagonists

Question 33

Which region of the nephron do thiazide related drugs act on

Answer 33

Distal tubule

Question 34

Which region of the nephron do loop diuretics act on

Answer 34

Loop of Henle

Question 35

Which classes of diuretics are relatively week

Answer 35

Thiazides and aldosterone antagonists

Question 36

Which diuretics are mainly used in hypertension and not heart failure

Answer 36

Thiazide diuretics

Question 37

Which diuretics are most commonly used in heart failure

Answer 37

Loop diuretics

Question 38

Which class of diuretics aren’t used in heart failure because there are better alternatives

Answer 38

K+ sparing diuretics

Question 39

Which class of diuretics have added value in heart failure patients and why

Answer 39

Aldosterone antagonists have added value in heart failure patients because as well as lowering blood volume they also supress the RAAS system. Hence they are ideal in the treatment of heart failure

Question 40

Give some examples of thiazide like drugs

Answer 40

Chlorothiazide Bendroflumethiazide chlortalidone

Question 41

What are the main loop diuretics

Answer 41

Furosemide and bumetanide

Question 42

Which class of diuretics have a strong diuretic effect

Answer 42

Loop diuretics

Question 43

Why are some patients on loo diuretics on massive doses

Answer 43

If the intrinsic function of the kidney is impaired as well/due to the heart failure then furosemide doesn’t work so well because it needs to be metabolised by the kidney first. Hence these patients are put on large doses

Question 44

Give some examples of K+ sparing diuretics

Answer 44

Spironolactone eplerenone amiloride triamterene

Question 45

Which K+ sparing diuretics are sometimes used in heart failure and why

Answer 45

Spironolactone and eplerenone have added value in that they are aldosterone antagonists. So therefore they are sometimes used in heart failure

Question 46

Amiloride if often used to treat patients in heart failure T or F

Answer 46

F

Question 47

Eplerenone is a much more expensive diuretic than spironolactone why are some patients switched onto this drug

Answer 47

Spironolactone is a pseudoestrogen that is associated with gynaecomastia and breast pain in males. Hence its sometimes necessary to switch patients to eplerenone

Question 48

What are the adverse effects of diuretics

Answer 48

Hypotension hypovolaemia hyponatraemia hypomagnesaemia hypocalcinaemia hyperuricaemia

Question 49

Which class of diuretics mainly causes hypotension and hypovolaemia

Answer 49

Loop diuretics

Question 50

What are the unique side effects with thiazide diuretics

Answer 50

Erectile dysfunction and impaired glucose tolerance

Question 51

What is the effect of isosorbide dinitrate

Answer 51

Causes vasodilation

Question 52

Below is some data from the isosorbide dinitrate/hydralazine trial comparing this combination therapy with placebo and another vasodilator prazosin. Describe what this data shows

Answer 52

Placebo group patients had a 50% mortality within 3 years. Prazosin treated patients has an almost identical mortality to placebo. Interestingly hydralazine/Isosorbide resulted in a 36% mortality reduction compared to placebo. Hence this treatment results in a significant risk reduction in mortality in heart failure patients. This is the first evidence that vasodilators actually increased outcomes and prognosis in patients with heart failure

Question 53

Hydralazine in combination with isosorbide dinitrate also increases LVEF T or F

Answer 53

T

Question 54

What treatment is used in heart failure patients if modern treatments fail

Answer 54

Hydralazine/isosorbide dinitrate