Pathology 3 Flashcards
What is cardiomyopathy? What does it result in?
- Any disease of cardiac muscle
* Changes in size of heart chambers and thickness of heart
What are classifications of cardiomyopathy? (4)
- Dilated
- Hypertrophic
- Restrictive
- Arrythmogenic right ventricular dysplasia
What is dilated cardiomyopathy? Histology?
- Floppy heart that is 2-3 times bigger than normal (350g)
* Histology (microscope) features are non-specific
Causes of dilated CM? (4)
- Genetics (50%) - genes that code for heart muscle proteins
- Alcohol (very common in alcoholics)
- Toxins
- Chemotherapy agents e.g. doxorubicin (important to assess heart prior to commencing chemo)
Rare causes of dilated CM? (2)
Clinical features? (2)
- Cardiac infection
- Pregnancy
Clinical features
- SOB
- Poor exercise tolerance
What is hypertrophic cardiomyopathy? What does it result in? Why is it significant?
- Big solid heart (not like DCM)
- Results in diastolic dysfunction (systole is fine but heart cannot relax) so causes outflow obstruction
- Significant because cause of sudden death in young athletes
Causes of hypertrophic CM?
Majority genetic e.g. beta myosin heavy chain, myosin binding protein C, alpha tropomyosin
Features of hypertrophic CM heart? (3)
Is the heart not healthier because it has stronger contraction? Why??
- Bulging intraventricular septum
- Outflow obstruction
- LV luminal reduction due to massive walls
NO, it is pathological - coronary arteries that supply heart do not increase in size so will have areas of hypoxia/ischaemia
Histology of hypertrophic CM?
Disorganised myofibres - swirls rather than linear
What is restrictive cardiomyopathy? What does it result in? (2)
- Lack of compliance due to rigidity - cannot stretch (relax) and fill so cannot contract properly to maintain CO
- Diastolic dysfunction due to lack of filling
- Bilateral dilation as a result of back pressure
Causes of restrictive CM? (5)
Deposition of something in myocardium
- Metabolic byproducts e.g. iron
- Amyloid
- Sarcoid
- Tumours
- Fibrosis (following infection etc)
What is amyloidosis?
Cause of restrictive CM - abnormal deposition of abnormal protein throughout body
Classification of amyloidosis?
- AA - related to chronic diseases like rheumatoid
- AL - light chains, abnormal immunoglobulin
- Haemodialysis….
……
See post-lecture slides
What tissues do amyloids affect? What is a cause of some forms of amyloidosis?
- All can affect the heart
- Some are isolated to heart e.g. senile cardiac amyloidosis
- May be localised to atrium
- Can be inherited
Histology of amyloidosis? What systems does amyloidosis affect?
- Waxy pink material
- Amyloid protein staisn positive for “congo red” dye
- Under polarised light, exhibits green birefringence
- Pan-systemic - every single vessel will contain protein
What is arrythmogenic right ventricular dysplasia? What are the effects? (2) What are sufferers prone to?
- Inherited disease - autosomal dominant with low penetrance so even though inherited, may not have disease
- Right ventricle becomes largerly replaced by fat
- Big and floppy, so non-contracile and prone to arrhythmias
- Sufferers prone to sudden death
What is myocarditis? Classifications? Most common cause?
- Inflammation of the heart
- Infectious vs non-infectious
- Most commonly infectious e.g. viral, bacterial, fungal, protozoal, helminthic
Most common cause of infectious myocarditis? Examples? (5)
Most are viral
- e.g. Coxsackie A and B
- ECHO virus
- Chaga’s disease - trypanosomiases in South America
- Borrelia burgdorferi - Lyme’s disease
- HIV
Features of infectious myocarditis heart? Histology?
- Thickened beefy myocardium
* Inflammatory infilrate on cardiac biopsy
Cause of non-infectious myocarditis? Examples? (3)
Immune mediated hypersensitivity reactions
- Hypersensitivity to infection e.g. rheumatic fever after strep throat
- Hypersensitivty to drugs e.g. eosinophilic myocarditis
- Systemic lupus erythematous (SLE)
Cardiac features of rheumatic fever? (4)
- Mitral stenosis with thickening and fusion of valve leaflets
- Short, thick chordae tendinae
- Myocardium also inflammed
- Aschoff bodies (immune cells, lymphocytes, macrophages - not quite a granuloma as central destruction region)
Pericarditis? Causes? (6)
Inflammation of pericardial layers
- Infection
- Immune mediated e.g. rheumatic fever
- Idiopathic
- Uraemic e.g. renal failure
- Post-MI e.g. Dressler’s syndrome
- Connective tissue disease e.g. SLE
Examples of infectious pericarditis? (4)
- Virus - esp ECHO virus produce serous effusions
- Bacterial - from elsewhere e.g. pneumonia resulting in purulent effusions
- Fungi - immunosuppressed, post-transplant, produce purulent effusions
- Tuberculus - caseous material in sac - produces CONSTRICTIVE pericarditis
Uraemic pericarditis? Pericarditis post-MI?
- Urea build-up can cause inflammation of pericardium
* Dressler’s syndrome (many weeks post-MI)
Complications of pericarditis? (5)
- Pericardial effusion
- Tamponade
- Constrictive pericarditis - fibrotic response, when collagen cross links it contracts, constricting the heart
- Cardiac failure
- Death
Endocarditis? Classifications?
- Affects heart lining but generally refers to inflammation of the valves
- Infectious or non-infectious
Causes of infectious endocarditis? (5)
- Virulent bacterial or fungal infection
- IV drug abuse and septicaemia e.g. staph aureus
- Prosthetic valves
- Congenital heart disease
- Calcific disease
Microbiology of infectious endocarditis?
????
Post lecture
Pathology of infectious endocarditis? (2)
- VEGETATIONS on heart valves
- Bacteria cause acute inflammation and bacterial and inflammatory cell products digest valve leaflets
….more post lecture
Cardiac complications of infectious endocarditis? (4)
- Acute valvular incompetence
- Cardiac output failure
- Abscesses
- Fistulae
MORE????
Systemic effects of infectious endocarditis? (5)
- Osler’s nodes
- Janeway lesions
- Roth spots
- Finger clubbing
- Splinter haemorrhages
…MORE :(
Non-infectious endocarditis?
See fucking post-lecture slides
Non-bacterial thrombotic endocarditis (NBTE)? Effects? (2) Associated with?
Non-invasive and doesn’t destroy valves
- Small and multiple vegetations
- Embolic disease
Associated with
- Cancer (marantic) esp mucinous adenocarcinomas
- Hypercoagulable states
What endocarditis is systemic lupus erythematous associated with? Effects? (3)
Libman-Sacks endocarditis
- Often asymptomatic
- Small sterile emboli
- Affects valves/chords
Carcinoid heart disease…
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