Systems Pathology: Heart Failure

Question 1

What is heart failure clinically manifested by?

Answer 1

Fluid congestion (backward failure)
Inadequate blood flow to tissues

Question 2

What type of failure does acute failure cause ?

Answer 2

Forward due to shock and rapid

Question 3

What failure does chronic failure cause

Answer 3

Backwards - congestion

Question 4

Compensatory mechanisms for heart failure

Answer 4

Ventricular chamber enlargement: increases amount of blood in ventricle, so ejects more, but at cost of fluid retention
Muscle mass increases- can eject more, but requires more oxygen to larger muscle
Sympathetic stimulation: increase heart rate, contractility, redistribution and retention of fluid.

Question 5

Cardiac remodelling

Answer 5

Hypertrophy in response to increased demands
Adrenergic stimuli, cytokines (TNFalpha) and angiotensin II mediate effects
Beneficial in increasing cardiac output
Also have adverse effects

Question 6

Remodelling signals

Answer 6

Adrenergic, angiotensin II, cytokines (TNF alpha)

Question 7

Benefit and harm of adrenergic remodelling signal

Answer 7

Contractility And hypertrophy

Myocyte apoptosis and toxicity

Question 8

Benefit and harm of angiotensin II remodelling signal

Answer 8

Hypertrophy

Changed expression of contractile proteins

Question 9

Benefit and harm of cytokines

Answer 9

Hypertrophy

Remodelling of matrix, dilatation

Question 10

How to know a chamber is failing

Answer 10

Dilating

Question 11

Pathology of LV failure

Answer 11

Raised end diastolic pressure leading to
Raised left atrial pressure leading to
Raised pulmonary capillary pressure leading o
Increased diffusion barrier for gas and increased interstitial fluid formation
Breathlessness

Question 12

Classification of heart failure

Answer 12

Class I - no limit to physical activity
Class II - slight limitation of activity (breathlessness/fatigue with moderate exercise)
Class III - marked limitation of activity (breathlessness with minimal exercise)
Class IV - severe limitation of activity (symptoms at rest)

Question 13

Pulmonary oedema histology

Answer 13

Alveolar walls are congested by fluid

Normally no stainable material - now has oedema

Question 14

Causes of LVF

Answer 14

Acute ventricular dysrhythmias
 MI and IHD
Long-standing hypertension 
Valve disease 
Cardiomyopathy and drugs 
Congenital heart disease

Question 15

Pathology of RVF

Answer 15

Right ventricular failure 
Raised end diastolic pressure 
Raised right atrial and JVP
Raised central venous pressure 
Liver distension and increased interstitial fluid formation

Question 16

Clinical example of RVF

Answer 16

Cor pulmonale

Question 17

Cause of cor pulmonale

Answer 17

Pulmonary emphysema 
Destroys alveolar walls, loss of lung capillaries 
Failure in lung ventilation
Hypoxia constricts pulmonary arteries 
Pulmonary hypertension

Question 18

What is CCF

Answer 18

Congestive cardiac failure

Combination of both right and left VF

Question 19

Cause of CCF

Answer 19

IHD
Other causes of LVF
Cardiomyopathies and drugs

Question 20

What is high output cardiac failure

Answer 20

Heart muscle essentially normal but output cannot adequately perfuse tissue

Question 21

Examples of high output cardiac failure causes

Answer 21

Arteriovenous fistula - blood bypasses tissue
Septic shock - vasodilation
Anaemia - oxygen requirements not met
Thyrotoxicosis - increased tissue demand