CVS Path Flashcards
Epi of Rheumatic Fever
2
- Kids
2. Endemic in LEDCs
Pathogenesis of Rheumatic Fever
- Untreated Strep Throat
- Causative Organism: Group A haemolytic Strep Pyogenes
- After latency period of 2-6w
- Anti-strep antibodies attack the heart
Causative organism of Rheumatic fever
Group A haemolytic strep Pyogenes
Latency period between strep throat and rheumatic fever
2-6w
Initial infection before rheumatic fever
Strep throat
Major Diagnostic Criteria for Rheumatic Fever
JONES
- Polyarthritis
- Pancarditis
- Subcutaneous Nodules
- Erythema Marginatum
- Sydenham’s Chroea
Minor diagnostic criteria for rheumatic fever
- Lab abnormalities (raised CRP)
- ECG abnormalities (prolonged PR)
- Fever
- Arthralgia
- Recent streptococcal infection
How do you diagnose Rheumatic fever?
Clinically
2 Major criteria
OR
1 major and 2 minor criteria (one of which must be ‘Recent Strep Infection’)
What is pancarditis?
Inflammation of the whole heart (all layers)
Perimyoendocarditis
How would you know there is pericarditis present in rheumatic fever?
- Pleural rub on auscultation
- Diffuse saddle shaped ST elevation
Signs of myocarditis in rheumatic fever
Aschoff bodies
- Giant cell granulomas
Signs of endocarditis in rheumatic fever
Valve disease
- Vegetations on valve leaflets
Anitschow cells
- Perivascular
- Chromatin
Causes of valve disease
4
- Age related degeneration (calcification)
- Function changes (IHD)
- Rheumatic fever
- Infective endocarditis
Causes of aortic stenosis
2
Calcific degeneration
Rheumatic Fever
Ix aortic stenosis
Doppler USS
Complications of aortic stenosis
5
LV hypertrophy
Angina
Syncope
LV failure
Sudden death
Causes of aortic regurgitation (incompetence)
Aortic root dilatation
Rheumatic valve disease
Complications of Aortic incompetence
2
LV dilation
HF
Risk factors for aortic stenosis
Bicuspid aortic valve
Causes of aortic root dilatation
Aortitis
Idiopathic
Causes of Mitral stenosis
Rheumatic fever
Complications of mitral stenosis
LA Hypertrophy
Pulmonary oedema
RV hypertrophy (Because more difficult to pump to lungs now)
Causes of mitral incompetence (regurgitation)
4
Floppy valve (degeneration)
Rheumatic fever
Dilated mitral valve annulus
Papillary muscle dysfunction
Complication of mitral regurgitation
LA dilation
AF
Mural thrombus
Embolic stroke
Most common cause and causative organism of infective endocarditis
Recurrent gingivitis
Viridans streptococci
How does the causative agent get to the heart valves to cause infective endocarditis?
Bacteraemia
Complications of Infective endocarditis
5
- Cusp or chordae rupture
- Valvular incompetence (damage)
- Myocarditis
- Thromboembolism
- Fever, malaise, weight loss
Predisposing factors for Infective endocarditis
4
- Structural abnormalities
- Incompetent valves - Prosthesis
- Prosthetic valves
- PCI - Bacteraemia
- IV drug use
- Sepsis - Immunosuppression
- DM
- Alcoholism etc
Main signs of infective endocarditis
7
Finger clubbing
Janeway lesions
Splinter haemorrhages
Osler’s Nodes
Poor dental hygiene
Roth Spots
PUO
What is Haematuria a sign of in the setting of infective endocarditis?
Thromboembolism
Resulting in renal infarcts
Resulting in Glomerulonephritis
What is bronchopneumonia a sign of in the setting of Infective endocarditis?
Pulmonary infarct
As result of Tricuspid valve endocarditis
Resulting in thromboembolism
Roth spots
Red spots with white centre
Seen in retina
in Infective Endocarditis
Splinter Haemorrhages
Lots of tiny blood clots
Run vertically
Under the nails
In infective endocarditis
Janeway Lesions
Painless, red, flat, papules on palms of hands and soles of feet
Infective endocarditis
Osler’s Nodes
Tender raised red spots on hands
Infective endocarditis
Define ‘True Aneurysm’
Localised, permanent, abnormal dilatation of a blood vessel
Define False Auneurysm
The vessel wall is completely breeched
Blood leaks out
Blood is contained by the surrounding adventitia and perivascular soft tissue
Cause of false aneurysm
Trauma (Surgical—> PCI)
Typical location of false aneurysm
Femoral A. (During PCI)
Cause of saccular or diffuse aneurysm
Atherosclerosis
Inflammatory disorders
Location of saccular or diffuse aneurysm
Abdominal Aorta
Thoracic aorta
Cerebral artery
Describe Saccular aneurysm
True aneurysm
Focal outpouching in the vessel wall
Describe Diffuse aneurysm
True aneurysm
Involve whole circumference of the vessel wall
Describe Dissecting aneurysm
Then aneurysm is within the vessel between the layers
Cause of Dissecting aneurysm
Connective Tissue disorders (Marfan’s)
Bicuspid aortic valve
Uncontrolled HTN
Atherosclerosis
Trauma
Typical location of Dissecting aneurysms
Aorta and main branches
Describe capillary / microaneurysm
Saccular outpouchings in capillaries
Causes of Capillary / Microaneurysms
HTN
Pericyte cell loss in DM (resulting in diabetic retinopathy)
Typical locations of capillary / microaneursyms
Cerebral capillaries
Retinal Capillaries
Describe mycotic aneurysm
Aneurysm caused by a bacterial infection of the vessel wall
Causes of Mycotic aneurysm
Infection (eg. Infective Endocarditis)
Septic emboli
Typical location for mycotic aneurysm
Any vessel
Consequences of aneurysms
Rupture —> Haemorrhage —> shock —> hypo-perfusion of vital organs —> end organ failure
Compression of adjacent structures
Thromboembolism formation
How is Myocarditis diagnosed?
Dallas criteria:
- On histological examination there is:
- Myocyte death
- Inflammatory infiltrate (T lymphocytes) - Ischaemia did not cause this
Causes of Myocarditis
9
Coxsackie
ECHO
Adenovirus (Kids)
Diphtheria
Meningococcus
Trypanosomiasis (Africa)
Chagas’ Disease (America)
Ionising radiation
Adriamycin
Complications of Pericarditis
Pericardial Effusion
Leading to Cardiac tampondae
Leading to obstructive shock and death
Pathogenesis of Cardiac tampondae
The pericardium is inflamed
The vessels become more permeable
Fluid leads out of the vessels and fills the potential space between the visceral and parietal pericardial layers (effusion)
This compresses the heart
Heart can’t fill properly
Complications of caseous or purulent / suppurative pericardial effusion
Constrictive pericarditis
Due to healing by fibrosis
Cause of caseous pericarditis
Fungi
Mycobacterium
Cause of blood stained pericardial effusion
Malignancy
Morphological features of shock in the Brain
Neuronal damage
Morphological features of shock in the Heart
Sub-endocardial necrosis
Morphological features of shock in the Kidneys
Acute Tubular Necrosis
Morphological features of shock in the lungs
Diffuse alveolar necrosis
Morphological features of shock in the Liver
Fatty change
Zone 3 necrosis
Morphological features of shock in the GIT
Haemorrhagic enteropathy
Types of shock
- Distributive
- Hypovolaemic
- Cardiogenic
- Obstructive
Causes of Pericarditis
Viral
Bacterial (TB
Post MI
Dressler’s
Carcinoma (metastatic spread)
Uraemia
Systemic disease
Cardiac surgery
Factors that determine whether ischaemia or infarction develops
4
Nature of blood supply
- Dual vs end-organ
- Anastamoses
- Arcades
Rate of occlusion
Vulnerability of tissue to hypoxia
Oxygen content of the blood
What affects the oxygen content of blood?
Anaemia
Altitude
Hyperventillation/ Hypoventillation
What are the 2 tyes of infarct morphology?
Red
Pale
Describe Red infarcts
Location:
- Loose, previously congested tissues with dual blood supply
Cause: Venous occlusion
Pathology: Re-perfusion damage
Eg: PE in lung
Describe pale infarcts
Location:
- Solid organs
- End-organs
Blood supply: Single
Eg. Heart, spleen, kidney
Causes of ischaemia and infarction
7
Thrombus
Embolus
Hyperviscosity
Atheroma
Spasm
Vasculitis
Compression
What does Virchow’s Triad predict?
Thrombosis
Virchow’s Triad
Changes in intimal surface of vessel wall
Changes in pattern of blood flow
Changes in blood constituents
Signs of arterial thrombosis in the limbs
5
Pale Perishingly Cold Pulselessness Paraesthesia Paralysis
Signs of venous thrombus formation in a limb
3
Red
Tender
Swollen
Fate of a thrombi
4
- Lysis and resolution
- Organisation
- Recanalisation
- Embolism
Types of embolism
- Thromboembolism
- Atheromatous embolism
- Amniotic fluid embolism
- Gas embolism
- Fat embolism
- Tumour
- Foreign body
- Infective agents
Layers of an artery from inside out
6
Endothelium
Intima
Internal elastic lamina
Media
External elastic lamina
Adventitia
Pathogenesis of ischaemia
Reduction in blood supply
Increased metabolic demand of tissue
Reduced oxygen carriage
Morphological appearance of Ischaemic tissue depends on:
- Extent of infarction
- Time since infarction
How do you measure myocardial necrosis?
Why?
Troponin
It is a myocardial enzyme that is released
Key histological features following myocardial infarction @:
<24hrs
>24hrs
D-W
W-Mths
< 24hrs : Electron microscopy shows swollen mitochondria
> 24hrs:
- Pale infarct
- Inflammation at periphery
- Monocytes lose striations
d-w:
- Macrophages
Mths:
- Repair by organisation and fibrosis
- Akinetic segment