Heart failure

Question 1

What is heart failure?

Answer 1

This is when the heart is failing to pump sufficiently to meet the bodies perfusion needs.

Question 2

What is the primary cause of systolic heart failure?

Answer 2

Ischaemic heart disease.

Question 3

What is high-output heart failure?

Answer 3

This includes conditions such as anaemia where cardiac output needs to be high due to reduced oxygen carrying capacity of the blood.

Question 4

Why can arrhythmias lead to heart failure?

Answer 4

These can cause a persistent fast beat which can lead to damage to the cardiac tissue.

Question 5

How can heart failure vary in severity?

Answer 5

It can lead to no limitation on physical activity in mild cases, and in acute cases patients may have symptoms at rest and be unable to carry out physical activity.

Question 6

What is ejection fraction?

Answer 6

This is the percentage of blood in the ventricle at the end of diastole which is pumped out during systole.

Question 7

What factors affect cardiac output?

Answer 7

Afterload (aortic impedance), preload (venous capacity), heart rate and myocardial contractility.

Question 8

What will the curve for cardiac output against end diastolic filling pressure look like for someone with gross failure?

Answer 8

There will be a peak in the centre of this curve, because whilst normally more filling leads to more stretching and therefore more force of contraction, in heart failure overfilling can cause more problems.

Question 9

What is systolic dysfunction of the heart characterised by?

Answer 9

The LV capacity is increased, and cardiac output is decreased. There can be fibrosis or necrosis of the myocardium.

Question 10

What is mitral valve incompetence?

Answer 10

This is where the mitral valve cannot close properly and is caused in heart failure because the ventricle stretches and the valve cannot increase in size and so is pulled apart.

Question 11

What structural changes can occur in heart failure?

Answer 11

There can be loss of muscle, uncoordinated or abnormal muscle contraction, increase in collagen or slippage of muscle fibres.

Question 12

What cellular changes occur in heart failure?

Answer 12

Myocytolysis, changes in calcium levels/ regulation, SR dysfunction and myocyte hypertrophy.

Question 13

How do baroreceptors respond in heart failure?

Answer 13

Reduced cardiac output leads to fall in BP and so sympathetic nervous system is stimulated leading to increased contractility, tachycardia and an vasoconstriction. Constant stimulation causes B adrenoceptors to become down regulated

Question 14

Name three effects of NA on the heart in heart failure.

Answer 14

Up regulation of RAAS, cardiac hypertrophy, myocyte apoptosis.

Question 15

What affect does RAAS have in heart failure?

Answer 15

This is upregulated, and this means that there is more angiotensin II.

Question 16

What is the consequence of increased angiotensin II?

Answer 16

Fluid retention due to increased aldosterone release, also vasoconstriction, atheroscleorosis, vascular hypertrophy, increase in LV size, hypertrophy, fibrosis, remodelling and apoptosis

Question 17

What can cause RAAS to be activated?

Answer 17

RAAS can become activated because there is decreased renal blood flow and this leads to SNS induction of renin.

Question 18

What are natriuretic hormones?

Answer 18

These are released from the tissue of the atrial walls when they are stretched.

Question 19

What is the effect of natriuretic hormones?

Answer 19

These increased sodium excretion in the kidney, causing lowering of blood volume and cause vasodilation.

Question 20

What is the name of the natriuretic hormone secreted from the ventricles?

Answer 20

Brain natriuretic hormone.

Question 21

Why does hyponatraemia sometimes present alongside heart failure?

Answer 21

This can be due to excess water retention, because there is reduced systemic resistance and tachycardia, and therefore increased CO.

Question 22

What is endothelin?

Answer 22

This is a vasoconstrictor secreted from vascular endothelial cells.

Question 23

What stimulates prostaglandin production in heart failure?

Answer 23

NA/RAAS. These act as vasodilatory on afferent renal arterioles to attenuate effects.

Question 24

What can affect the vasodilation balance in heart failure?

Answer 24

NO synthase can become blunted.

Question 25

What is the role of bradykinin in heart failure?

Answer 25

This promotes natriuresis,vasodilation and stimulation of prostaglandin production.

Question 26

What is the role of tumour necrosis factor in heart failure?

Answer 26

It suppresses Myocardial function.

Question 27

What systemic effects can result from heart failure?

Answer 27

SNS/RAAS/NOreduction and increased endothelin all exacerbate the clinical symptoms. If there is reduced blood supply to skeletal muscle this causes a reduction in muscle mass. If this affects the limbs or respiratory system then this leads to fatigue and exercise intolerance.

Question 28

State how glomerolus filtration rate varies in heart failure.

Answer 28

In the early stages, this is maintained by haemodynamic changes however there is increased sodium and water retention. In severe heart failure, the GFR drops and there is a rise in serum urea and creatinine.

Question 29

What is diastolic dysfunction?

Answer 29

This is where there is a lack of ability of the ventricle to relax and therefore this causes Impared LV filling and the other heart failure problems.

Question 30

What structural changes are seen in the heart in diastolic dysfunction?

Answer 30

Concentric left ventricle hypertrophy.

Question 31

What type of oedema is common in left heart failure?

Answer 31

Basal pulmonary crackles and some peripheral oedema.

Question 32

What can cause right heart failure?

Answer 32

Problems with the lungs primarily as the right heart is having to pump against a higher pressure.
The most common cause is secondary to left heart failure.

Question 33

What are common symptoms in right heart failure?

Answer 33

Raised JVP, hepatic enlargement, pitting oedema, ascities, pleural effusion,

Question 34

Are ACE inhibitors usefulness in treatment of heart failure?

Answer 34

ACE inhibitors block AT1 to AT2, and also a similar pathway for breakdown of bradykinin. Which leads to less vasodilation.

Question 35

What pharmacological treatments can be used in heart failure?

Answer 35

Diuretics, ACe inhibitors, B blockers, nitrates, spiranolone,