L18: Heart Failure

Question 1

What is heart failure

Answer 1

The inability of the heart to supply adequate blood flow and therefore oxygen to peripheral tissue and organs

Question 2

What are the symptoms of heart failure

Answer 2

Weight gain
Shortness of breath
Increased swelling 
Trouble sleeping frequent cough 
Loss of appetite

Question 3

What happens in the heart failure which tries to increase CO

Answer 3

Increase SNS
Increase volume loading
Hypertrophy

Question 4

What are the common causes heart failure

Answer 4

Myocardial infarction

Question 5

What is myocardial infarction

Answer 5

When a thrombus forms in the coronary artery

So the myocardium is perfumed by one artery

Question 6

What occurs when there is no blood flow to a specific area of the muscles

Answer 6

Ischaemia

Question 7

What is ischaemia

Answer 7

No blood flow

Question 8

What happens to the tissue when there is ischaemia

Answer 8

Hypoxic
Hypercapnic
Acidotic
Nutrient depleted

Question 9

What is the tissue at risk of if ischaemia occurs

Answer 9

Necrosis

Question 10

What is necrosis

Answer 10

Tissue death

Question 11

How does a thrombus develop in the coronary arteries

Answer 11

1) as we age we develop fatty plaques in the arteries
2) the plaque ruptures and releases substances to platelet activation
3) platelet forms a thrombus which completes block the coronary artery

Question 12

What is the treatment for MI

Answer 12

Percutaneous coronary intervention (PCI)

Question 13

What does a PCI involve

Answer 13

Inserting a catheter into the coronary artery which punctures the thrombus
Catheter inflates the ballon so vessel is stretched
A stent is fitted so the vessel remain open and blood flows

Question 14

What happens to the tissues when we re-introduce blood flow via PCI

Answer 14

Tissue can die further due to sudden reperfussion

Question 15

Do we have any interventions in place to stop the cell death after PCI

Answer 15

No

Question 16

What are the other causes of heart failure

Answer 16

Hypertension

Contractile dysfunction

Question 17

Why does hypertension cause heart inability to pump

Answer 17

Increases the afterload (pressure that the heart has to work against)

Question 18

How does a contractile dysfunction lead to Heart failure

Answer 18

Cant pump

Question 19

What happens to the starling curve in heart failure

Answer 19

Decreases

Question 20

Why does the starling curve decrease

Answer 20

We lose our inability to stretch sacromere and stretch to give a contraction to increase the SV

Question 21

Where are baroreceptors found in the body

Answer 21

Aortic arch

Carotid sinus

Question 22

What is the afferent nerve of the carotid sinus

Answer 22

CN9/ glossopharyngeal nerve

Question 23

What is the afferent nerve of the aortic arch

Answer 23

Vagus nerve /CN10

Question 24

If there is a fall in stroke volume due to a change in the starling curve what happens to the ABP

Answer 24

Abp= co X TPR
Abp= (SV X HR) X TPR
Decreases

Question 25

What happens to the afferent nerve activity of the baroreceptors when they detect a decrease in the ABP

Answer 25

Afferent activity decreases

Question 26

Where does the afferent nerve input into

Answer 26

The CNS to NTS

Question 27

What happens after inputting into the NTS

Answer 27

1) NTS inhibits the nucleus ambiguus so the PNS vagal activity to the SAN decreases 2) RVLM is activated which increases the sympathetic pre-ganglionic nerve to the SAN and heart rate increases 3) sympathetic activity also causes vasoconstriction 4) SNS also causes an increase in SV by increasing the contractility of the cardiac myocytes 5) SNS causes adrenaline release form the adrenal gland which increase the HR and SV

Question 28

What does an increase in SV and HR do

Answer 28

Increase cardiac output

Question 29

What is the consequence of the persistent activation of the SNS to the heart

Answer 29

Hypertrophy Loss of adregenic sensitivity due to less beta receptors expressed Dysfunction with calcium homeostasis

Question 30

How do we get a calcium homeostasis dysfunction due to the persistent activation of SNS

Answer 30

1) SNS leads to sarcoplasmic reticulum overload with calcium as it open voltage gated calcium channels 2) the overload of calcium causes calcium to lead during diastole 3) calcium becomes removed by the NA+/CA2+ exchanger 4) sodium is brought into the cell which causes depolarisation 5) we get a small contraction during the diastole interval and if it meets the threshold it leads to an ectopic AP 6) SNS also causes increases PKA activity which brings in calcium back to the sarcoplasmic reticulum by stimulating SERCA

Question 31

When there a reduced ABP what happens in the kidney

Answer 31

1) renin is released 2) renin coverts angiotensinogen to angiotensin 1 3) ACE converts angiotensin 1 to angiotensin 2 4) angiotensin 2 causes the release of aldosterone which brings in water by bringing in sodium and therefore water follows

Question 32

What does the effect of bringing in water do to the EDV

Answer 32

Increase it

Question 33

What effect does increase in EDV have to the SV

Answer 33

Increase it to maintain CO

Question 34

What happens to the SV in late stage heart failure

Answer 34

Decreases because we lose sacromeres which cannot stretch despite the increase in the EDV

Question 35

What happens when we get a mismatch in the left and right CO

Answer 35

Oedema

Question 36

Where can oedema occur

Answer 36

Pulmonary | Systemic

Question 37

In left heart failure where do we get the oedema

Answer 37

Pulmonary

Question 38

In right heart failure where do we get the oedema

Answer 38

Systemic

Question 39

Why do we get an oedema forming when there is an increased blood volume

Answer 39

An increase in blood volume increases the hydrostatic pressure in the capillaries Fluid moves into the interstitial space to give oedema

Question 40

When we get pulmonary oedema what happens to diffusion of oxygen

Answer 40

Decreases due to an increases diffusion distance created by the fluid

Question 41

Which receptors does a decrease in oxygen stimulate

Answer 41

Peripheral chemoreceptors

Question 42

What is the treatment for pulmonary oedema

Answer 42

100% o2 supply Diuretics Ace inhibitors AT1 receptor antagonist

Question 43

Why do we get hypertrophy of the heart

Answer 43

Due to an increase in blood pressure or SNS activity

Question 44

How can we lower BP

Answer 44

Give vasodilator

Question 45

How can we stop the stimulation of SNS

Answer 45

Beta blockers