Theme 9: Cardiovascular Pathology III Flashcards
What is peripheral vascular disease?
atherosclerosis of arteries supplying legs (or arms), leading to narrowing of the vessel lumen and restriction of blood flow
Who gets peripheral vascular disease? (epidemiology)
- age > 40
- obesity
- smokers
- family history
- men (or post-menopausal women)
- dyslipidaemia
- those with a PMH including: diabetes, hypercholesterolaemia, hypertension
Why is the prevalence of peripheral vascular disease higher in men?
oestrogen is a protective factor so it protects women until menopause
Explain the process of atherosclerosis (5 steps)
- Normal artery
- Endothelial dysfunction
- Fatty streak formation
- Stable (fibrous) plaque formation
- Unstable plaque formation
Explain the pathogenesis of peripheral vascular disease
- Gradual artherosclerosis (chronic) or plaque rupture/ thrombus formation (acute)
- Narrows lumen
- Reduced blood flow
- Ischaemia
- Tissue damage/ death
What are the clinical features of acute peripheral vascular disease?
6 Ps: Pale Pulseless Painful Paralysed Paraesthetic (pins and needles) Perishingly cold
What are the clinical features of chronic peripheral vascular disease?
Asymptomatic: reduced pulses
Symptomatic: intermittent claudication
Critical limb ischaemia: rest pain and tissue loss
What is giant cell artertitis? (temporal arteritis)
A type of vasculitis affecting the large arteries in the head. Considered a medical emergency as it can lead to blindness
Who is at risk of giant cell arteritis?
- older individuals, VERY rare if < 50 years old
- US/europe
- F > M
- PMH of polymyalgia rheumatica
What causes giant cell arteritis?
- autoimmune damage to blood vessels
- type IV hypersensitivity
Explain the pathogenesis of giant cell arteritis?
- Chronic granulomatous inflammation
- Thickens wall of artery
- Narrows lumen
- Reduced blood flow
- ischaemia
- tissue damage and death
What are the clinical features of giant cell arteritis?
- fatigue
- weight loss
- fever
- tender superficial temporal artery
- jaw claudication (when eating)
- blurred vision
- blind ness
- stroke
What is infective endocarditis?
infection and inflammation of the endocardium (lining of the heart), mainly involving valves
Who is at risk of IE?
Patients with:
- structurally abnormal valves (rheumatic heart disease, congenital heart disease, age-related calcification)
- foreign material in heart (ICD, prosthetic valves)
- immunosuppression
- bacteraemia - IVDU, long term IV catheters
but can occur in healthy patients with virulent organisms e.g S.aureus
What causes IE?
- Streptococcus - viridans / bovis
- Staphylococcus - aureus / epidermis
- Fungi - candida, aspergillus
How does IE make you ill?
- Damage to endothelium over valve
- Fibrin deposition
- Circulating bacteria colonise this fibrin
- Vegetations form
then either
-vegetations damage valves–> HR, murmur
-bacteria in vegetations form local abscess –> AV block
-bits of vegetations break off –> emboli/ infarction
-immune response to infecction - fever, weight loss
What are the clinical features of IE?
- splenic infarct
- splinter haemorrhage
- jane way lesions
- osler’s nodes
- roth spots (retinal haemorrhage)
What is pericarditis?
inflammation of the pericardial sac
how are the different types of pericarditis classified?
- Acute (<6 months): then further classified based on the type of fluid surrounding the cells - serofibrinous, caseous, haemorrhagic and purulent
- Chronic (>6 months): constrictive
What can cause pericarditis?
- Infections - viruses (coxsackie B), bacteria, TB, fungi, parasites
- Autoimmune- rheumatic fever, SLE, scleroderma, drug hypersensitivity, post-MI
- Miscellaneous - uraemia, radiation, neoplasia, trauma
How does chronic pericarditis make you ill?
- collagen deposition
- fibrosis and thickening of pericardium
- fibrosis reduces filling of heart
- HF
Acute pericarditis is further named based on what type of fluid surrounds the cells. What is it called if:
- Fibrin
- Neutrophils
- RBCs
- Caseous necrosis
- Serofibrinous
- Purulent
- haemorrhagic
- TB
what are the clinical features of pericarditis?
- central chest pain
- pericardial friction rub
- fever
- pericardial effusion (may lead to tamponade)
- HF
What is myocarditis?
inflammation of the myocardium
What are the possible causes of myocarditis?
- Infections
viruses, bacteria, fungi, protozoa, helminths - Immune mediated
- post group A streptococcus
- SLE
- drugs
- rejection of heart transplant
other: sarcoidosis
Explain the pathogenesis of myocarditis
- inflammation of myocardium
- dysfunctional myocardium
- electrical dysfunction = arrhythmias/ sudden death
mechanical dysfunction = heart failure
What is the definition of rheumatic fever?
a rare complication of group A streptococcal pharyngitis that affects the heart (and other parts of the body)
Who gets rheumatic fever?
- children
- developing countries (rare in UK now)
- often have recent Hx of core throught
What causes rheumatic fever?
untreated group A streptococcus infection (streptococcus pyogenes) + immune cross reactivity
Explain the pathogenesis of rheumatic fever
- group A strep infection
- Antibodies made against M protein on the surface of the strep pyogenes bacteria
- Antibodies also recognise proteins on surface of cells (self antigens) in the heart, skin, joints and CNS
Type II hypersensitivity = antibody
What are the clinical features of rheumatic fever
Heart – endocarditis, myocarditis, pericarditis (pancarditis when all together)
- Endocarditis – mitral valve stenosis “fish mouth” most common valve lesion, vegetations “verrucae”
- Skin – subcutaneous nodules, erythema marginatum
- Joints – arthritis
- CNS – sydenhams chorea
- General symptoms – fever, malaise
What is a cardiomyopathy and what are the 4 main types?
= heart muscle disease
- Dilated
- Hypertrophic
- Restrictive
- Arrythmogenic right ventricular cardiomyopathy
What is the epidemiology and aetiology of hypertrophic cardiomyopathy?
Epidemiology: all ages and genders
Aetiology: Genetic
Explain the pathogenesis of hypertrophic cardiomyopathy
- impaired ventricular filling as wall of heart is v thick so chambers are small
- +/- left ventricular outflow obstruction
- relative ischaemia
What are the clinical features of hypertrophic cardiomyopathy?
- HR
- arrhythmias and sudden death
- mural thrombus formation +/- embolization
- relative ischaemia –> coronary arteries are still same magnitude so cannot supply hypertrophic muscle
What is the epidemiology and aetiology of dilated cardiomyopathy?
Epidemiology: any age but commonly males aged 20-50 Aetiology: -often unknown -AD genetic -alcohol -catecholamines -pregnancy -haemachromatosis -infection
How does dilated cardiomyopathy make you ill?
dilated and thin walled ventricular chambers –> impaired ventricular pumping i.e decreased LVEF
What is the aetiology of restrictive cardiomyopathy?
- idiopathic
- secondary:
- amyloidosis
- sarcoidosis
- metastatic tumours
- deposition of metabolites
How does restrictive cardiomyopathy make you ill?
impaired ventricular filling
What is the epidemiology and aetiology of arrythmogenic RV cardiomyopathy?
Epidemiology: most common in young males
Aetiology: genetic AD 1 in 5000
Explain the pathogenesis of arrythmogenic RV cardiomyopathy
-RV myocyte adhesion impaired due to mutation in desmosome proteins –> cells detach –> fibrofatty tissue forms in attempt to repair damage –> interferes with muscle contraction and electrical conduction
What are the clinical features of RV Arrythmogenic cardiomyopathy??
- palpitations
- syncope
- HR
- thrombus
- arrhythmias and sudden cardiac death
Which valve does rheumatic fever tend to affect?
mitral valve –> and causes regurgitation more than stenosis
