Pathophysiology of heart failure

Question 1

Main causes of heart failure =

Answer 1

Ischemic heart disease
Hypertension
Dilated Cardiomyopathy 
Congenital 
Valvular etc.

Question 2

New descriptions of HF

Answer 2

Acute

Chronic

Question 3

Pre-load =

Answer 3

Venous return.

Question 4

Filling pressure =

Answer 4

the pressure in the ventircles just before it starts to contract

Question 5

What does increased preload do (Starlings’ law)

Answer 5

Stretches myocardial fibres and myocardial contraction increases/is restored

Question 6

After load =

Answer 6

Outflow resistance/peripheral resistance.

Question 7

What causes outflow resistance?

Answer 7

Pulmonary and systemic resistance

Volume of blood ejected

Question 8

If preload/end diastolic volume increases, what does this do to after load?

Answer 8

Increases after load

Question 9

What is increased in HF, SNS or PNS

Answer 9

SNS - originally to provide inotrophic support, chronically increases neurohormonal activation and myocyte apoptosis

Question 10

What can happen to LV during remodelling

Answer 10

Hypertrophy
Intersistial fibrosis
Loss of myocytes

Question 11

Acute heart failure =

Answer 11

Rapid onset of symptoms and signs of HF

Question 12

Examples of acute HF presenation:

Answer 12

Pulmonary oedema
Anasarca
Cardiogenic shock

Question 13

Starlings law in relation to HF

Answer 13

As muscle failures, need to increase preload to get ventricles to work.

Question 14

What occurs in left ventricular pump failure to increase the BP

Answer 14

• fall in Bp - increased sympathetic - vasoconstriction - increase afterload
• fall in renal perfusion - RAAS - retention - increased preload

Question 15

Clinical features of pulmonary oedema:

Answer 15

Tachypnoea
Orthopnoea
Crackles
Use of accessory muscles
Pink frothy sputum

Question 16

O2 sat in pulmonary oedema

Answer 16

<90%

Question 17

What can be seen of CXR in pulomonary oedema due to heart failure =

Answer 17

Enlarged heart (>50%)
Kerley B lines (straight horizontal lines)

Question 18

Normal pressure in lungs

Answer 18

Colloid = hydrostatic. Small amount of fluid leaves and is drained

Question 19

Formation of pulmonary oedema

Answer 19

Blood backs up into pulmonary capillaires - increased hydrostatic pressure - more fluid into interstitial space.

Question 20

What is anasarca?

Answer 20

Generalied oedema

Question 21

What sided HF does anasarca occur in?

Answer 21

Right

Question 22

Features of anasarca:

Answer 22

Peripheral oedema
Acities
Pleural effusions

Question 23

Anasarca develops over

Answer 23

Days - weeks

Question 24

What might a patient with anasarca notice?

Answer 24

Gradual weight gain

Question 25

What causes anasarca?

Answer 25

Fall in CO - fall in renal perfusion - increased ADH and aldosterone - Na+ and H2O retention

Question 26

3 features of chronic heart failure =

Answer 26

a. symptoms of HF b. evidence of cardiac dysfunction (imaging, ECG) c. response to treatment

Question 27

4 models of progression of chronic heart failure =

Answer 27

1. Haemodynamic 2. Neurohormonal 3. Peripheral 4. Metabolic

Question 28

Haemodynamic model:

Answer 28

``` Pump failure results in reduced BP and renal perfusion Increased sympathetic and RAAS Vasoconstriction and Na+/H2O Increased afterload and preload Worsens ```

Question 29

Neurohormonal:

Answer 29

``` Increased ANP, BNP Increased ADH Increased Endothelin Increased RAAS Adrenergic activation ```

Question 30

Endothelin function

Answer 30

Vasoconstriction

Question 31

Natriuretic peptides function

Answer 31

Vasodilation Increased Na+/H2O excretion Inhibit renin, ACE

Question 32

What hormones can cause fibrosis within the heart?

Answer 32

Aldosterone

Question 33

ANP =

Answer 33

Atrial natriuretic peptide

Question 34

BNP =

Answer 34

B-type naturietic peptide

Question 35

What is always raised in HF?

Answer 35

BNP

Question 36

In HF there is a switch from what to what (peripheral model)

Answer 36

Type 1 slow twitch to type 2 fast twitch skeletal muscle

Question 37

Increased ventilation increases exercise =

Answer 37

Ergoreflex

Question 38

In HF there is a shift between (catabolism/anabolism) to (catabolism/anabolism)

Answer 38

Anabolism to catabolism

Question 39

Metabolic model:

Answer 39

Increased cost/energy cost | Resistance to anabolic hormones