Flashcards in Cardiac Histopathology Deck (45):
Histological findings post MI
1. Under 6hours
2. 6-24 hours
3. 1-4 days
4. 5-10 days
6. 1-2 weeks
1. Under 6hours (normal histology, CK-MB also normal)
2. 6-24 hours (loss of nuclei, homogenous cytoplasm, necrotic cell death).
3. 1-4 days (infiltration of macrophages, peak troponin in at 24-48 hours)
4. 5-10 days (removal of debris)
6. 1-2 weeks (granulation tissue, new blood vessels, myofibroblasts, collagen synthesis)
7. 2weeks+ (strengthening, decellularising scar tissue)
Complications of MI (4 main groups)
1. Mechanical (e.g. CCF)
2. Arrhythmias (e.g. VF)
3. Pericardial (e.g. Peri-infarct associated pericarditis, pericardial effusion).
4. Mural thrombus formation (can embolise)
5 main mechanical complications of MI
1. Cardiogenic shock (contractile dysfunction due to loss of active muscle).
2. CCF (due to ventr dysfunction and arrhythmias)
3. LV infarct (papillary muscle dysfunction can lead to mitral regurg)
4. Cardiac rupture (ventricular wall (haemopericardium), septum (left to right shunt), papillary muscle (mitral regurg)).
5. Ventricular aneurysm (usually develops more than 1 month post MI).
main arrhythmic complication of MI
1. VF (usually in first 24 hours, common cause of sudden death)
90% of patients develop an arrhythmia post MI.
Describe clinical features and the timespan of dressers syndrome.
Persistent low grade fever,
Chest pain (usually pleuritic)
Maybe pericardial effusion
Usually occurs 2-3 weeks post MI, but can be longer.
MI basic definition
Myocardial cell death due to prolonged ischaemia.
What is the difference between HFpEF and HFrEF
HFpEF- preserved ejection fraction. Diastolic heart failure. Ventricles do not relax properly to allow ventricular filling.
HFpRF- reduced ejection fraction. Systolic heart failure. Ventricles do not contract effectively to pump oxygenated blood around the body.
What are normal and abnormal ejection fraction percentages?
EF>75% indicates a hypertrophic cardiomyopathy.
Normal EF is usually 55-70%. However you can still have a normal ef, but HFpEF.
EF 40-55 indicates damage but may not be heart failure.
Give 6 common causes of heart failure
2. Ischaemic heart disease
4. Valve disease
5. Dilated cardiomyopathy
Give 6 clinical features of heart failure
Dyspnoea, orthopnoea, PND, wheeze, fatigue, RV failure, peripheral oedema
2 main causes of RV failure
Chronic severe pulmonary HTN
4 Heart failure investigations and findings?
BNP, CXR, ECG, echo
3 types of cardiomyopathy
Dilated (systolic dysfunction)
Hypertrophic (diastolic dysfunction)
Restrictive (diastolic dysfunction)
7 causes of dilated cardiomyopathy
Idiopathic, alcohol, peripartum, genetic, sarcoidosis, haemochromotosis, myocarditis
Causes of HCM
Genetic, glycogen storage diseases
Name 3 typical features of HCM
1. Thick walled
Histologically myocyte disarray.
3 causes of restrictive cardiomyopathy (connective tissues issues)
Sarcoidosis, amyloidosis, radiation induced fibrosis.
What is ARVC
Arrhythmogenic right ventricular cardiomyopathy
Myocyte loss with fibrofatty replacement typically affecting the RV.
What 4 main systems does acute rheumatic fever affect, and how?
Joints: arthiritis, synovitis
Skin: erythema marginatum
Neurological: encephalopathy, Sydenham's chorea
What is erythema marginatum?
Erythema (redness of the skin or mucous membranes) specifically involving pink rings on the torso and inner surfaces of the limbs which come and go for as long as several months. It is found primarily on extensor surfaces.
What is the peak age of onset for acute rheumatic fever?
How long after the initial infection does ARF develop?
What is the most common infection for ARF to develop after?
Strep throat (lancefield group a strep)
What are the 4 main clinical features of ARF
Fever, tachycardia, malaise, migrating polyarthralgia
What is the pathology of ARF
Antigenic mimicry. Immune response to antigens from previous streptococcal infection cross-reacts with myocardial antigens.
What are the 3 key findings on histology for ARF? Describe them.
1. Beady fibrous vegetations (warty 'verrucae' found near valve leaflet closure lines)
2. Aschoff bodies (small giant cell granulomas)
3. Anitschkov myocytes (regenerating myocytes)
What are the diagnostic criteria, tests, results and treatment of ARF?
Jones criteria, along with raised ESR and ASOT (anti-streptolysin O). Benzylpenicillin or erythromycin in penicillin allergic patients.
What are the 4 main types of vegetative endocarditis
1. Rheumatic heart disease
2. Infective endocarditis
3. Non-bacterial thrombotic endocarditis (Marantic)
4. Libman-Sacks Endocarditis
Describe the pathology and vegetation characteristics of infective endocarditis
Invasion of heart valves or mural endocardium by microbe.
Large irregular masses on valve cusps, extending into the chordae (chordae are like stringy valve tendons connecting to papillary muscle).
Describe the pathology and vegetation characteristics of Non-bacterial thrombotic endocarditis (Marantic)
Caused by DIC/hypercoagulable states.
Small bland vegetations formed of thrombi are attached to valve leaflet closure lines
Describe the pathology and vegetation characteristics of Libman-Sacks Endocarditis
Pathology unknown. Associated with immune disorders (SLE, Anti-phospholipid syndrome).
Small, sterile, platelet rich, warty vegetations.
Basic Infective Endocarditis definition
colonisation or invasion of endocardium by pathogens (usually bacteria) causing an inflammatory response..
Give 6 causes of infective endocarditis bacteraemia
1. Poor dental hygiene.
2. Dental treatments
3.Soft tissue infection
6. Cardiac surgery/pacemakers
Give 6 predisposing factors for infective endocarditis
1. Rheumatic heart disease
2. Mitral valve prolapse
3. Calcified valves
4. Bicuspid aortic valve
5. Prosthetic valves
6. Congenital defects
Name 2 causative organisms for Acute and Subacute infective endocarditis
Acute: Staph aureus, Strep pyogenes
Subacute: Strep Viridans, Staph epidermis, Coxiella, Mycoplasma, Candida
What is the difference in vegetation morphology and spread between acute and subacute infective endocarditis?
Acute: Larger and more localised lesions. Aortic spread.
Subacute: Smaller, friable soft lesions. Chordae spread.
Give 10 clinical features of infective endocarditis (5 are more specific)
Fever, malaise, anaemia, rigors, splenomegaly
New murmur, roth spots (retinal hemorrhages with pale centres), osler's nodes, janeway lesions, splinter hemorrhages
What valves are usually affected in infective endocarditis?
Usually mitral or aortic.
UNLESS IVDU/cannula, etc. where right sided valves are involved
What are the diagnostic criteria and treatment for infective endocarditis?
Duke's criteria, benzylpenicillin and gentamycin
What valves are usually involved in chronic rheumatic valve disease?
What are the physical pathological signs of chronic rheumatic valve disease?
Thickening of valve leaflet. Thickening, shortening and fusion of chordae tendinae.
What is the main cause of aortic stenosis?
Calcification. Process is sped up by the presence of a bicuspid valve
What are the clinical signs of mitral valve prolapse on ausculatation?
mid-systolic click and late systolic murmur
What are the 3 classifications of aortic regurgitation and their sub-groups?
Rigidity (rheumatic, degenerative)
Dilatation (valve is insufficiently large to cover the increased area.e.g. immune mediated issues, marfan's dissecting aneurysm)