Systems pathology: HF

Question 1

Heart failure

Answer 1

a condition caused by impairment of heart’s function to act as a pump

Question 2

clinical manifestation of HF:

Answer 2

Backward failure- fluid congestion - causes chronic failure

Forward failure- inadequate blood flow to tissues- causes acute failure

Question 3

effects of AII

Answer 3

adrenal cortex-> aldosterone-> Na and fluid retention-> increase blood volume

ADH-> Na and fluid retention-> increase blood volume
(baroreceptors and osmotic receptor stim. )

vasoconstriction

cardiac and vascular hypertrophy

Question 4

what stimulates the kidney to release renin

Answer 4

sympathetic stimulation
hypo-perfusion
decreased sodium delivery

Question 5

compensatory mechanisms of HF

Answer 5

ventricular chamber enlargement- increase amount of blood ejected but more fluid retention

muscle mass increase- increase ejection but more oxygen needed

increase SNS- increase hr, contractility, redistribution and retention of fluid

Question 6

is heart failure passive

Answer 6

no

Question 7

cardiac remodelling

Answer 7

hypertrophy
adrenergic stimuli, cytokines TNF alpha and AII mediate
increase CO

Question 8

Adrenergic benefits and harms

Answer 8

hypertrophy
contractility

myocyte apoptosis and toxicity

Question 9

Angiotensin II benefits and harms

Answer 9

hypertrophy

changed expression of contractile proteins

Question 10

cytokines TNF alpha benefits and harms

Answer 10

hypertrophy

remodelling of matrix
dilatation ( a dilating chamber is a failing chamber)

Question 11

LV failure

Answer 11

raised EDP
raised LA pressure 
raised pulmonary capillary pressure 
-> increased diffusion of gas exchange 
-> increased interstitial fluid formation (pul. oedema) 
breathlessness

Question 12

LV leads to:

Answer 12

insufficient pump power- obstruction outflow to valve, aorta, arteries, arterioles

obstruction to inward flow- pericardial effusion, constructive pericarditis

Question 13

pulmonary oedema histology

Answer 13

alveolar walls congested by fluid

oedema in alveolar spaces (normally no stainable tissue)

Question 14

causes of LVF

Answer 14

acute ventricular dysrhythmia 
MI and IHD 
hypertension longstanding 
valve disease (aortic and mitral) 
cardiomyopathies and drugs 
congenital heart disease

Question 15

RV failure

Answer 15

raised EDP
raised right atrial and left venous jugular pressure
raised central venous pressure
-> liver distention (abdominal discomfort)
-> increased interstitial fluid formation (peripheral oedema)

Question 16

causes of RVF

Answer 16

failure of LV
acute- pulmonary TE
chronic- chronic lung disease, pul hypertension (cor pulmonale)
valve disease (pulmonary, tricuspid) is rare

Question 17

congested liver

Answer 17

dark areas- centrolobular congestion

pale areas- periportal fatty change

Question 18

Cor pulmonale due to pulmonary emphysema

Answer 18

emphysema destroys alveolar walls 
loss of lung capillaries 
failure of lung ventilation 
hypoxia constricts pulmonary arteries 
pulmonary hypertension

Question 19

Congestive cardiac failure, causes

Answer 19

combination of left and right VF
most common is IHD followed by VF
cardiomyopathies and drugs

Question 20

high output cardiac failure

Answer 20

heart muscle is normal but cannot adequately perfuse tissue

atriovenous fistula- blood bypasses tissue
septic shock- vasodilation
anaemia- O2 requirements not met
thyrotoxicosis- increased tissue demand - heat, useless energy