Histopathology 6 - Vascular and Cardiac pathology

Question 1

What are the 3 stages of atheroma development?

Answer 1

1. Raised lesion
2. Soft lipid core
3. White fibrous cap

Question 2

Recall the 7 steps of atheroma pathophsyiology

Answer 2

1. Endothelial injury
2. LDL enters intima and gets trapped in intimal space
3. LDL is converted into oxidised LDL –> inflammation
4. Macrophages take up OxLDL via scavenger receptors –> foam cells
5. Foam cell apoptosis –> inflammation and cholesterol deposition to form plaque core
6. Endothelium expresses more adhesion molecules –> more macrophages and T cells enter plaque
7. VSMCs form fibrous cap

Question 3

What % atheroma of a vessel lumen is considered ‘critical stenosis’?

Answer 3

70%

Question 4

What is prinzmental angina?

Answer 4

Coronary artery spasm

Question 5

Which parts of the cardiac muscle are affected by an infarction of the LAD?

Answer 5

Anterior wall of left ventricle, anterior septum and apex

Question 6

Which parts of the cardiac muscle are affected by an infarction of the RCA?

Answer 6

Posterior wall of left ventricle, posterior septum and posterior wall of right ventricle

Question 7

Which parts of the cardiac muscle are affected by an infarction of the LCx?

Answer 7

Lateral wall of left ventricle

Question 8

What are the 4 most important complications of MI?

Answer 8

1. Contractile dysfunction (eg cardiogenic shock)
2. Arrhythmia
3. Myocardial rupture
4. Pericarditis

Question 9

What is Dressler’s syndrome?

Answer 9

Pericarditis occuring weeks-months post-MI

Question 10

What is the average time between MI and myocardial rupture?

Answer 10

4-5 days

Question 11

What is the prognosis of papillary muscle rupture following MI?

Answer 11

Rubbish - very high mortality

Question 12

What is the most common cause of sudden cardiac death?

Answer 12

Lethal arrhythmia

Question 13

What is restrictive cardiomyopathy?

Answer 13

Normal size heart but with large atria - may be due to amyloidosis

Question 14

Recall 3 possible causes of aortic regurgitation

Answer 14

Infective endocarditis
Marfan’s
Ankylosing spondylitis

Question 15

What is Monckeberg atherosclerosis?

Answer 15

Focal calcification of the media of small-medium sized vessels; no associated inflammation

Question 16

What histological findings would be found within 6 hours of an MI?

Answer 16

Normal histology and normal CK-MB

Question 17

What histological findings would be found 6 -24 hours following an MI?

Answer 17

Loss of nuclei
Homogenous cytoplasm
Necrotic cell death
Coagulative necrosis

Question 18

What histological findings would be found 1-4 days following an MI?

Answer 18

Infiltration of polymorphs and macrophages

Question 19

What histological findings would be found 5-10 days following an MI?

Answer 19

Removal of debris

Question 20

What histological findings would be found 1-2 weeks following an MI?

Answer 20

Granulation tissue
New blood vessels
Myofibroblasts
Collagen synthesis

Question 21

What histological findings would be found in the months following an MI?

Answer 21

Strengthening, de-cellularising scar tissue

Question 22

Recall the possible complications of MI

Answer 22

Mnemonic = PACE MAKERED

Papillary muscle dysfunction
Arrhythmia
Ccf
Effusion (pericardial)

Mural thrombus
Aneurism (ventricular)
(K)ontractile dysfunction
Early pericarditis
Rupture of venticular wall
Elevation of ST segment
Dressler's syndrome

Question 23

What types of cardiomyopathy can be caused by sarcoidosis?

Answer 23

Dilated and restrictive

Question 24

Which type of cardiomyopathy is associated with alcohol misuse?

Answer 24

Dilated

Question 25

Is the pathology of cardiomyopathy systolic or diastolic dysfunction in

a) dilated CM
b) hypertrophic CM
c) restrictive CM?

Answer 25

Dilated: systolic

Hypertrophic and restrictive: diastolic

Question 26

What is the HOCM?

Answer 26

Hypertrophic obstructive CM = septal hypertrophy resulting in an outflow tract obstruction

Question 27

What mutation is associated with Hypertrophic CM?

Answer 27

Beta-myosin heavy chain

Beta-HMC - HMC is HCM rearranged

Question 28

Recall the major criteria for Rheumatic fever diagnosis

Answer 28

CASES
Carditis
Arthritis
Sydenham's chorea
Erythema marginatum
Subcutaneous nodules

Question 29

What is the main pathogen in rheumatic fever?

Answer 29

Lancefield group A strep

Question 30

How is ‘antigenic mimicry’ involved in rheumatic heart fever?

Answer 30

Cell-mediated immunity and antibodies to streptococcal antigen cross-react with myocardial antigens

Question 31

How are vegetations seen on heart valves in rheumatic fever described?

Answer 31

Small and warty, “verrucae”

Question 32

What is Libman-Sacks endocarditis

Answer 32

Unknown pathogenesis - associated with SLE and anti-phospholipid syndrome

Question 33

Differentiate the likely causative organisms in acute vs subacute infective endocarditis

Answer 33

Acute: Staph aureus/ pyogenes

Subacute: strep viridans/ epidermis/ HACEK/ coxiella/ candida/ mycoplasma

Question 34

Recall the major and minor Duke criteria for infective endocarditis

Answer 34

Major:
Pos BC growing typical IE organism OR 2 pos BCs >12hrs apart

Minor:

• RF
• Fever >38
• Thromboembolic phenomena
• Immune phenomena
• Pos BCs not meeting major criteria

Question 35

How many of Duke’s criteria are needed for diagnosis of infective endocarditis?

Answer 35

2 major

1 major and 3 minor

5 minor

Question 36

What abnormality in the mitral valve might be caused by rheumatic fever vs IE?

Answer 36

RhF: mitral stenosis

IE: mitral regurgitation