Histopathology 7: Vascular and cardiac pathology

Question 1

Describe dressler’s syndrome ?

Answer 1

Pericarditis weeks-months after an M.I

Question 2

What histological findings are seen < 6 hours post MI ?

Answer 2

normal histology

Question 3

What histological findings are seen 6- 24 hours post MI ?

Answer 3

• loss of nuclei
• Homogenous cytoplasm
• necrotic cell death

Question 4

What histological findings are seen 1-4 days post MI ?

Answer 4

-infiltration of polymorphs and macrophages to clear debris

Question 5

What histological findings are seen 5-10 days post MI ?

Answer 5

-debris cleared

Question 6

What histological findings are seen 1-2 weeks post MI ?

Answer 6

• granulation tissue
• myelofibroblasts depositing collagen
• revascularistation

Question 7

What histological findings are seen weeks - months post MI ?

Answer 7

-scar tissue

Question 8

What does Nutmeg liver indicate ?

Answer 8

hepatic cirrhosis most likely due to right sided heart failure

Question 9

List 5 causes of dilated cardiomyopathy ?

Answer 9

• Alcohol
• post partum
• sarcoidosis
• Haemochromatosis
• genetic: Duchenne’s muscular dystrophy

Question 10

List 2 causes of Hypertrophic cardiomyopathy ?

Answer 10

• Genetic

- storage diseases

Question 11

List 3 causes of restrictive Cardiomyopathy ?

Answer 11

• Sarcoidosis
• Amyloidosis
• Radiation

Question 12

Which type of cardiomyopathy shows myocyte disarray ?

Answer 12

• Hypertrophic

Question 13

Describe what is meant by HOCM ?

Answer 13

• Hypertrophic obstructive cardiomyopathy

- Septal hypertrophy leading to outflow tract obstruction

Question 14

Crescendo - decrescendo murmur heard over the left lower sternal edge and bifid pulse.

Most likely diagnosis

Answer 14

HOCM

Question 15

List 5 features of acute rheumatic fever ?

Answer 15

CASES

Carditis (pancarditis)
Arthritis 
Sydenham's chorea 
Erythema marginatum
Subcutaneous nodules

Question 16

Which valve is most commonly affected by rheumatic fever ?

Answer 16

Mitral valve

Question 17

What is the most common causative organism of rheumatic fever ?

Answer 17

Group A streptococcus (tonsillitis)

Question 18

Histology of the mitral valve and heart shows beady fibrous vegetations, Aschoff bodies and Anitschkov myocytes.

Most likely diagnosis ?

Answer 18

Rheumatic heart disease

Question 19

Which pathological mechanism leads to Rheumatic heart disease ?

A) Antigenic mimicry
B) Auto-immune
C) Inborn error of metabolism
D) Bacterial colonisation

Answer 19

A) antigenic mimicry

Question 20

Which type of endocarditis is associated with SLE ?

Answer 20

Libman-sacks endocarditis

caused by antigen-antibody complex deposition

Question 21

Which organism is the most common cause of acute infective endocarditis in IVDU ?

Answer 21

S.Aureus

Question 22

Which organism is the most common cause of subacute infective endocarditis ?

Answer 22

Strep. Viridans

Question 23

Which valve tends to be affected in IVDU with infective endocarditis ?

Answer 23

Right sided valves

Question 24

Which genetic syndrome is associated with bicuspid aortic valve ?

Answer 24

Turner’s syndrome

Question 25

Which valve disorder is associated with a mid systolic click and late systolic murmur ?

Answer 25

Mitral valve prolapse

Question 26

RF for atherosclerosis

Answer 26

``` age (40-60) gender - postmenopausal women genetics hyperlipidaemia hypertension smoking diabetes mellitus ```

Question 27

describe the pathogenesis of atherosclerosis

Answer 27

response to injury hypothesis - chronic inflammatory and healing response of the arterial wall to endothelial injury endothelial injury - LDL accumulation in the intima myocytes move to the intima - macrophages - foam cells cytokine release + lipid accumulation smooth muscle proliferation also important GF - PDGF, FGF, TGF-alpha fatty streak = earliest change atherosclerotic plaques occur most at points of disturbed flow - ie where arteries branch consequences = obstruction + rupture

Question 28

define critical stenosis

Answer 28

when demand>supply occurs at around 70% occlusion causes stable angina

Question 29

describe acute plaque change

Answer 29

rupture - exposes prothrombitic plaque contents erosion - exposes prothrombotic subendothelial BM haemorrhage into plaque - increases size

Question 30

describe IHD

Answer 30

``` leading cause of death worldwide group of conditions resulting from myocardial ischaemia presents as: - angina - MI - chronic ischaemic HD with HF - sudden cardiac death ``` plaque sites: - first few cm of LAD or LCX - entire length of LCA

Question 31

what is ACS

Answer 31

stable plaque becomes unstable | generally leads to superimposed thrombus

Question 32

what is angina pectoris

Answer 32

transient ischaemia that does not produce myocyte necrosis types = stable, prinzmetal, unstable stable = no plaque disruption prinzmetal = due to coronary artery spasm unstable - disruption of plaque with a superimposed thrombus

Question 33

define MI

Answer 33

death of cardiac muscle due to prolonged ischaemia - myocardial blood supply compromised - loss of contractiliy within 60s - HF can preceded myocyte death - potentially reversible - irreversible after 20-30 mins LAD > RCA > lateral LV

Question 34

describe histological changes post MI

Answer 34

under 6 hrs - nomal 6-24 - loss of nuclei, homogenous cytoplasm, necrotic cell death 1-4 days - infiltration of polymorphs then macrophages (clear up debris) 5-10 days - removal of debris 1-2 weeks - removal of granulation tissue, new blood vessels, myofibroblasts, collagen synthesis weeks - months - strengthening, decellularisisng scar

Question 35

cinical features of MI

Answer 35

10-15% asymptomatic (elderly, diabetes) - CK, troponins - 1/2 deaths within 1 hr reperfusion injury - can cause stunned myocardium hibernating myocardium - lower metabolusm

Question 36

complications of MI

Answer 36

``` contractile dysfunction - cardiogenic shock arrhythmia myocardial rupture - can cause cardiac tamponade pericarditis RV infarction infarct extension ventricular aneurysm papillary muscle rupture chronic ischaemic heart disease ```

Question 37

what is sudden cardiac death

Answer 37

unexpected death from cardiac causes in individuals without symptomatic heart disease usually due to lethal arrhythmia often caused by ischaemia-induced electrical instability

Question 38

featres of cardiac failure

Answer 38

congestive - both sides left sided - SOB, pul oedema right sided - peripheral oedemia, nutmeg liver histology: - dilated heart - scarring and thinning of walls - fibrosis and replacement fo ventricular myocardium

Question 39

types of cardiomyopathy

Answer 39

dilated (too thin) - progressive loss of myocytes (idiopathic, infective, toxic, hormonal, genetic) hypertrophic (too thick) - LVH, beta myosin heavy chain ab in some cases restrictive (too stiff) - impaired ventricular compliance, normal size but big atria

Question 40

causes of cardiac valve disease

Answer 40

chronic rheumatic valvular disease - immune cross reactivity - almost always mitral - M>A>T>P - button holes Calcified aortic stenosis - most common - outflow obstruction Aortic regurg - caused by: rigidity (rheumatic, degenerative), destruction (microbial endocarditis), disease of AV ring (eg marfans) Endocarditis - usually LS unless IV drug users

Question 41

difference between true and false aneurysm

Answer 41

true - all layers of the wall dilate false - extravascular hematoma causes: congenital (marfans), atherosclerosis, hypertension dissection more common high up lower more likely to rupture