Pathology of Non-Ischaemic Heart Disease

Question 1

classification of cardiomyopathies

Answer 1

dilated
hypertrophic
restrictive

arrhythmogenic right ventricular dysplasia

Question 2

describe dilated cardiomyopathy

Answer 2

2/3 x larger than normal heart
heart is weak, flabby and floppy
non-specific microscopic features

Question 3

causes of dilated caridomypathy

Answer 3

genetics - genes encoding heart muscle proteins (desmin, dystrophin - muscular dystrophy);
autosomal dominant 
autosomal recessive 
X-linked
mitochondrial

toxins
alcohol - ethanol toxicity or metabolites or nutritional deficiencies
doxorubicin - chemotherapy agents

rare;
cardiac infection
pregnancy

Question 4

symptoms and signs of dilated cardiomyopathy

Answer 4

features of heart failure
shortness of breath
poor exercise tolerance
low ejection fraction (low cardiac output)

Question 5

describe hypertrophic cardiomyopathy

Answer 5

muscle-bound, big solid hearts
strong contraction
diastolic dysfunction (not systolic as contraction is fine)
- heart cannot relax
eventually causes outflow tract obstruction, bulging inter-ventricular septum and LV luminal reduction
disorganised myofibres

sudden death

Question 6

causes of hypertrophic myopathy

Answer 6

genetic;
beta myosin (heavy chain)
myosin binding protein C
alpha tropomyosin

Question 7

describe restrictive cardiomyopathy

Answer 7

stiff heart - ventricles become stiff, but not necessarily thickened
lack of complaince
diastolic dysfunction - does not fill well
can look normal
biatrial dilatation as result of back pressure

Question 8

causes of restrictive myopathy

Answer 8

may require biopsy!

deposition of something in myocardium
metabolic byproducts - iron
amyloid
sarcoid - multi-system granulomatous disorder
tumours
fibrosis (following radiation)

Question 9

describe amyloid

Answer 9

abnormal deposition of abnormal protein
pansystemic
tendency to form beta pleated sheets
body can’t get rid of them

all different types can affect the heart
some are isolated to the heart
senile cardiac amyloidosis
can also be inherited

waxy pink material, stains positively for congo red and exhibits apple green birefringence under microscope

Question 10

classification of amyloid

Answer 10

AA – relate to chronic diseases (rheumatoid)
AL – light chains, abnormal immunoglobulin
Haemodialysis associated – beta 2 microglobulin
Familial forms: Transthyretin
Diabetes
Alzheimer’s

Question 11

describe arrhythmogenic right ventricular dysplasia (ARVD)

Answer 11

right ventricle becomes largely replaced by fat

becomes big and floppy

Question 12

symptoms of ARVD

Answer 12

pre-syncope
syncope
arrhythmia
sudden death

Question 13

causes of ARVD

Answer 13

genetic disease;
autosomal dominant (may just be carrier)

Question 14

describe causes of viral myocarditis

Answer 14

coxsackie A and B
ECHO virus
plus many other viruses

chaga’s disease
borrelia burgdorferi - lyme’s disease
HIV

Question 15

describe non infectious myocarditis

Answer 15

immune mediated hypersensitivity reactions;
infection - rheumatic fever after strep sore throat
drugs - eosinophilic myocarditis

systemic lupus erythematosus (SLE)

Question 16

describe rheumatic fever effect on heart

Answer 16

classic mitral stenosis with thickening and fusion of valve leaflets
short thick chordae tendinae
myocardium also patchily inflamed

aschoff bodies under microscope

Question 17

causes of pericarditis

Answer 17

infection;
ECHO virus, bacterial (e.g. from pneumonia), fungi, TB

immune mediated - rheumatic fever
idiopathic
uraemic (renal failure)
post MI (Dressler's syndrome)
connective tissue dse e.g. SLE

Question 18

describe pericarditis as a complication of MI

Answer 18

dressler’s syndrome (secondary form of pericarditis)
many week post MI
immune mediated - damaged heart muscle release previously un-encountered material that stimulates an immune response

Question 19

complications of pericarditis

Answer 19

pericardial effusion
tamponade 
constrictive pericarditis 
cardiac failure
death

Question 20

describe endocarditis

Answer 20

affects heart lining but refers to inflammation of valves

can be infectious or non-infectious

Question 21

pathology of infectious endocarditis

Answer 21

aggregates of organisms on heart valves known as vegetations
bacteria excite acute inflammation and bacterial and inflammatory cell products digest the valve leaflets
vegetations are also friable and can cause emboli

Question 22

complications of infectious endocarditis

Answer 22

acute valvular incompetence
high output cardiac failure
abscess, fistula, pericarditis

Question 23

describe non-bacterial thrombotic endocarditis

Answer 23

non-invasive, does not destroy valves
small and multiple vegetations 
can cause embolic disease
associated with cancer and mucinous adenocarcinomas 
hypercoaguable states

Question 24

describe lupus

Answer 24

libman-sacks endocarditis
small sterile emboli
undersurfaces of the valves or on chordae
range of changes - often small asymptomatic deposits or significant valvulitis

Question 25

describe carcinoid syndrome

Answer 25

carcinoid tumours - neoplasms of neuroendocrine cells
seen in any mucosa - common in GI tract and lung
neuroendocrine component - release hormones
carcinoid syndrome occurs when tumour has metastasised to the liver

Question 26

signs of carcinoid syndrome

Answer 26

right sided cardiac valve disease
tricuspid and pulmonary insufficiency
flushing skin
nausea, vomiting, diarrhoea

excess - 5HIAA, serotonin, histamine, bradykinin - production by tumour

Question 27

tumours of the heart

Answer 27

primary tumours are very rare as cardiac muscle cells are end differentiated
most common cardiac tumour - atrial myxoma
secondary tumours can occur

Question 28

describe atrial myxoma

Answer 28

90% in atria, usually left
can cause;
ball/valve obstruction
tumour emboli

may develop endocarditis
associated with systemic fever and malaise - IL-6