Cardiovascular Flashcards
What is ischaemia?
result of impaired blood flow or perfusion of tissues depriving it of oxygen and nutrients
What are the effects of ischaemia?
reversible
dependent of duration of ischaemia
dependent on tissue metabolic demands
What is infarction?
death (necrosis) of tissue as a result of ischaemia
What are the effects of infarction?
irreversible
tissues vary in ability to repair and regenerate
What do infarctions illicit?
inflammatory response
What determines whether ischaemia or infarction develops?
nature of blood supply (single or biphasic)
duration of occlusion
vulnerability of tissue to hypoxia
oxygen content of blood
What are red infarcts?
venous occlusions
Where do red infarcts occur?
loose tissues (like lung)
tissues with dual circulation
tissues which have been congested before and have referfusion damage
Where do pale infarcts occur?
solid organs
single blood supply
What causes ischaemia and infarction?
thrombosis embolism spasm atheroma compression vasculitis steal hyperviscosity
What 3 areas cause ischaemia or infarction?
things in lumen
things in wall
things outside wall
What 3 factors cause thrombosis?
Virchow's triad: changes in 1. intimal surface of vessel 2. pattern of blood flow 3. blood constituents
Explain how a thrombus forms on an atheromatous plaque
turbulent blood flow around plaque (changes to flow)
changes in surface overlying atheromatous plaque (changes to intimal wall)
platelet activation due to these changes
activation of clotting cascade
deposition of thrombus
What is propgation?
growth of thrombus in direction of flow
What are the clinical effects of arterial thrombosis?
distal tissues become: oale cold painful infarcted
What are the clinical effects of venous thrombosis?
usually happens in leg distal tissues become: red swollen tender
What are the 4 fates of a thrombus?
- lysis and resolution
- organisation
- recanalisation
- embolism
What is recanalisation?
blood flow restored with multiple small vessels but leaves behind scar and residual thrombus
What is an embolism?
mass of material that can move within vascular system and become lodged in a vessel blocking its lumen
What are emboli usually derived from?
thrombus
What is the most common type of embolism?
thromboembolism
What other types of embolus are there?
atheromatous emboli amniotic fluid (parturition) gas fat tumour (metastasis) foreign material infective agents
Describe the structure of a normal artery from outside in
adventitiae external elastic lamina media internal elastic intima endothelium
What is an atheroma?
deposition of tissue within intimal layers
What is deposited in atheromas?
fat macrophages
inflamatory cells
fibrovascular connective tissue
What do atheromas cause?
luminal narrowing and vascular insufficiency
What are the major risk factors for atheromas?
age sex hyperlipidaemia smoking hypertension diabetes mellitus sedentary lifestyle
What are the 3 types of atheromatous lesions?
fatty streak
fibrolipid plaque
comlicated lesion
WHat is a fatty streak?
linear elevations of lipid laden macrophages
What is a fibrolipid plaque?
bigger lesion that a fatty streak
fat
fibrosis
fibroblasts present
What is a complicated lesion?
narrowing
endothelial erosion with thrombosis
plaque rupture and fissuring
aneurysm formation
What sites are typically affected by atheroma?
high pressure vessels lower abdominal arota/iliac coronary popliteal descending thoracic aorta internal carotid and circle of willis
What vesselsWhat are complications of an atheroma?
narrowing of vessel
thrombus on plaque
fissuring and cracking (bleeding onto plaque)
aneurysm
What is the s[ectrum of ischaemic heart disease?
angina
myocardial infarction
sudden death
What is the main cause of ischaemic heart disease?
atheroma
What are teh risk factors for ischaemic heart disease?
family Hx smoking +++ diet lifestyle race (blackF) obesity diabetes mellitus hypertension hyperlipidaemia stress
What is the pathogenesis of ischaemic heart disease?
when blood supply becomes inefficient through:
reduction in blood supply (atheroma)
increased demand (muscle hypertrophy)
reduced oxygen carriage (anaemia)
What is the pathogenesis of ischaemic heart disease?
when blood supply becomes inefficient through:
reduction in blood supply (atheroma)
increased demand (muscle hypertrophy)
reduced oxygen carriage (anaemia)
What does angina present with?
reversible chest pain
can be stable (exertion related) or unstable (unpredictable)
What does MI present with?
central crushing chest pain
left arm and neck radiation
What are the 3 commonest arteries to be affected in MI?
LAD
RCA
LCX
What happens the ventricles in acute MI?
necrosis of left ventricle
inflammatory infiltration
fibrous repair
necrotic muscle releases enzymes (troponin)
Explain the ECG changes depending on where the MI occurs?
LAD “artery of sudden death”
infarction of anterior aspect of myocardium
ECG changes in anterior chest leads
LCA
lateral infarction
ECG changes I, AVL, lateral chest leads
RCX
ECG changes II, III and AVF (inferior leads)
What changes within the first 24 hours of MI?
nothing to be seen
within first 6 hours swollen mitochrondria microscopically
What can be seen 24 hours after MI?
infarction pale
inflammatory reaction
myocytes lose typical striations
What can be seen days to weeks after MI?
dead myocytes removed by macrophages
healing by repair, organisation and progressive fibrosis
formation of fibrous scar
WHat can be seen months after MI?
akinetic segment
What are the complications of MIs?
sudden death arrhythmias angina cardiac failure mitral incompetence
What causes sudden death in MI?
VF
What causes arrhythmias in MI?
damage to conducting system in first few days
What causes angina?
ischaemia
What causes cardiac failure?
muscle necrosis/arrhythmia
What causes mitral incompetence?
papillary muscle damage
What causes pericarditis to be a complication of MI and when does it occur?
transmural infarct with pericardial inflammation
2-4 days
What causes cardiac rupture in MI and when does it occur?
wall weakening following muscle necrosis and acute inflammation
3-5 days
Wjat causes mural thromosis in MI? When does it occur?
ischaemia and endothelial damage
7+ dyas
What causes ventricular aneurysm in MI?
muscle necrosis/arrhythmia
What causes Dressler’s syndrome in MI?
autoimmune
What does Dressler’s syndrome present with?
chest pain
fever
effusions
Compare and contrast myocardial rupture and ventricular aneurysm
What is arterial blood pressure?
measure of the force exerted on arterial walls by circulating blood
What is the diagnostic threshold of systolic and diastolic blood pressure?
systolic 140mmHg
diastolic 90mmHg
What is hypertension a major risk factor for?
stroke MI HF CKD cognitive decline premature death
What are risk factors for primary/essential hypertension?
age FHx african/caribbean origin high salt lack of excercise overweight smoking alcohol stress
What are 5 areas that can cause secondary hypertension?
renal endocrine coarctation of aorta medications pregnancy
What endocrine causes for hypertension are there?
pheochromocytoma
Cushing’s
hyperaldosteronism
What medications can cause hypertension?
NSAIDs
oral contraceptive
steroids
What are renal parenchymal diseases?
diabetic nephropathy chronic glomerulonephritis polycystic kidney disease chronic tubulointerstitial nephritis hypertensive renal disease
What is renal artery stenosis?
decrease in blood flow through one/both main renal arteries or branches
What causes renal stenosis?
atherosclerosis fibromuscular dysplasia (FMD)
How is renal stenosis diagnosed?
CT
angiography
MRI
What is FMD?
fibromuscular dysplasia
pathogenic thickening of arterial wall
Who does FMD commonly affect?
younger adults
mainly females 20-50s
What is produced in the adrenal cortex?
aldosterone
cortisol
testosterone precursor
What is produced in the adrenal edulla?
adrenaline
noradrenaline
What is produced in the adrenal medulla?
adrenaline
noradrenaline
What can cause elevated aldosterone?
aldosteronoma
What can cause elevated noradrenaline and adrenaline?
phaeochromocytoma
What can cause Cushing’s syndrome/hypercortisolism?
ectopic ACTH due to lung cancer
pituitary adenoma
adrenal adenoma
corticosteroids
How does coarctation of the aorta cause hypertension?
reduced blood flow in lower half of body and lower BP
higher BP in arms and upper body
What are the clinical manifestations of hypertension/what organs are affected?
cardiovascular system
kidneys
retina
What happens to the heart in hypertension?
left ventricular hypertrophy
What is hypertrophic cardiomyopathy?
asymmetrical left ventricular hypertrophy
often involves IV septum
genetic disease
can cause sudden death in young adults
What is the difference between atherosclerosis and arteriolosclerosis?
ATHERO - asymmetrical narrowing of lumen of LARGER vessels by LIPID accumulation within INTIMA
ARTERIOLO - symmetrical narrowing of lumen of SMALLER vessels by deposition of PROTEIN within the wall of blood vessels
What is haemorrhagic stroke?
rupture of small cerebral micro-aneurysms
What is hypertensive nephrosclerosis?
progressive renal impairment caused by chronic poorly controlled hypertension
What can results from hypertensive arteriolar nephrosclerosis?
CKD
What is hypertensive retinopathy?
thickened blood vessel walls reduces blood flow
causes ischaemia and infarction
damage to blood vessels then causes bleeding and loss of vision
Who is typically affected by rheumatic fever?
children with Group A haemolytic streptococci throat infection
When do symptoms of rheumatic fever generally present after Group A haemolytic streptococcal throat infections?
2-6 weeks
How is rheumatic fever diagnosed?
2 major or 1 major and 2 minor criteria and evidence of previous streptococcal infection
What is evidence of previous streptococcal infection?
rising antistreptolysin O titre
What are major criteria for rheumatic fever?
carditis polyarthritis erythema marginatum Sydenham's chorea subcutaneous nodules
What is erythema marginatum?
skin rash over trunk and limbs
round, pale-pink centre surrounded by slightly raised red outline
What is Sydenham’s chorea?
rare neurological disorder
sudden onset chorea
random-appearing, continuous, involuntary movements
often includes the face and tongue
What are the minor criteria for rheumatic fever?
fever arthralgia raised CRP (lab abnormalities) ECG abnormalities (prolonged PR interval) evidence of streptococcal infection
What is the hallmark of rheumatic fever?
pancarditis
What can patients present with in rheumatic fever?
pleural effusion and fibrinous pericarditis
man
manifests as audible rub
What is an Aschoff body?
when pericarditis develops into myocarditis and endocarditis
valves are swollen and infiltrated with inflammatory cells
small vegetations on valve leaflets
What causes the architectural disruption to the vales and the long term complications of rheumatic fever?
fibrotic healing response
What does an Aschoff body consist of and what is it surrounded by?
central core of collagen
small Aschoff giant cells
What is seen by the arrow?
Anitschkow cells
long bar of central chromatin
What are the 2 overarching areas causing valvular heart disease?
stenosis
incompetence
What is stenosis of valves?
thickened and/or calcified causing obstruction to flow
What is incompetence of heart valves?
regurgitataion or insufficiency
lose normal function and leak
What are causes of valve disease?
age - calcification functional changes rheumatic fever floppy valves congenital defects infective endocarditis
What are 2 causes of aortic stenosis?
calcific degeneration
rheumatic fever
What are complications of aortic stenosis?
left ventricular hypertrophy angina syncope left ventricular failure sudden death
What are causes of aortic incompetence?
aortic root dilatation
rheumatic valve disease
What is the pathophysiology of left ventricular hypertrophy in aortic stenosis?
left ventricular chamber becomes pressure loaded
compensatory hypertrophy
What is seen in the picture?
calcific aortic valve stenosis
What is seen in the picture?
congenital bicuspic aortic valve stenosis
What is seen in the picture?
aortic valve regurgitation due to dilatation of aortic root
What causes mitral stenosis?
rheumatic fever
What are the complications of mitral stenosis?
pulmonary hypertension
left atrial hypertrophy
right ventricular hypertrophy
What causes mitral incompetence?
floppy valves
rheumatic fever
dilated mitral valve annulus
papillary muscle dysfunction
What can be seen in the picture?
mitral valve leaflet expanded
projecting back into left atrium
What is infective endocarditis
acute/chronic disease resulting from infection of focal area of endocardium (usually over valve)
What does infective endocarditis look like?
vegetations
friable masses containing organisms, platelets, fibrin and inflammatory cells
What are predisposing factors to infective endocarditis?
structural cardiac abnormalities
prostheses and catheters
bacteraemias
altered immunity
What are local complications of infective endocarditis?
chordae/ cusp rupture
valvular incompetence
myocarditis
What are systemic complications of infective endocarditis?
fever
weight loss
malaise
What are systemic complications of infective endocarditis?
fever
weight loss
malaise
What is heart failure?
clinical syndrome characterised by typical symptoms accompanied by signs caused by structural/functional cardiac abnormality resulting in reduced cardiac output and/or elevated intracardiac pressures at rest or exertion
What is the equation for ejection fraction?
sttroke volume/ end diastolic volume
What is reduced LVEF?
<40%
How many classes are there in heart failure?
4
1 is no limitation
2 mild limitation - rest normal but exertion causes fatigue, dyspnoea or palpitations
3 marked limitation - comfortable at rest but gentle exertion is symptomatic
4 HF symptoms occur at rest and are exacerbated by exertion
What causes heart failure?
myocardial abnormality
What are the 3 Frank-Starling mechanisms in heart failure?
myocardial adaptations
endothelial function
antidiuretic hormone
What myocardial adaptations occur in heart failure?
myocyte hypertrophy fibrosis apoptosis abnormal calcium homeostasis gene expression
What happens to circulating levels of endothelin in heart failure?
increase
What happens sodium levels in HF?
decrease due to high levels of antidiuretic hormone
What happens the activity of NO in HF?
blunted
What are the 3 neurohumoral systems activated in heart failure?
- RAAS
- sympathetic nervous system
- natriuretic peptides
How is the RAAS system activated in HF?
↓ cardiac output
↓ renal perfusion
RAAS activated
What does RAAS do?
salt and water retention
↑ venous pressure
toxic effects of myocardial cells
What medications are used if HF specifically for RAAS?
ACE inhibitors and ARBs
Why does the sympathetic nervous system get activated in HF?
CO = SV x HR
↓ SV due to myocardial impairment
↑ compensatory HR
What are ANP and BNP and what do they do?
natriuretic peptides
counter RAAS
reduces blood volume, arterial pressure and central venous pressure
What happens to lead to left-sided heart failure?
pulmonary congestion and oedema
pleural effusions
blood pools in the pulmonary circulation
What is the consequence of LSHF?
blood stasis in left chambers
inadequate perfusion of downstream tissues
What increases in risk with left atrial dilatation?
atrial fibrilation and thrombus
What can be seen in the alveoli in LSHF?
haemosiderin-laden macrophages
Why can pulmonary effusions arise from LSHF?
elevated capillary pressure
What are the clinical symptoms of LSHF?
dyspnoea
orthopnoea
PND
What happens to the kidney in severe hypoperfusion?
impaired excretion of nitrogenous
pre-renal azotaemia
What happens the brain in advanced heart failure?
hypoxic-ischaemic encephalopathy
irritability
progress to come
How does right sided heart failure commonly arise?
as a result of LSHF
What can also cause RSHF?
pulmonary hypertension
right ventricular infarction
right ventricular cardiomyopathy
adult congenital heart disease
In RSHF what is congested?
systemic and portal veins
NOT lungs
What is the pathology of congestion of vessels in RSHF?
hepatomegaly (nutmeg liver)
splenomegaly (platelet sequestration)
congestion and oedema of bowel wall
What happens in systemic congestion in RSHF?
fluid accumulation in pleural, pericardial or peritoneal spaces
ankle and pre-tibial oedema
pre-sacral oedema
anasarca (generalised massive oedema)
What is an aneurysm?
localised, permanent abnormal dilatation of blood vessel
What is a false aneurysm?
haematoma which lies alongside vessel often enveloped by thin rim of adventitial tissue
communicates with vascular lumen via narrown defect in media
What is a true aneurysm?
weakness in vessel wall composed of intima, media and adventitia
What is the underlying pathology for false aneurysm and where is it normally found?
trauma
femoral artery
What is the underlying pathology for saccular and diffuse aneurysm and where is it normally found?
atherosclerosis
abdominal aorta
thoracic aorta
cerebral artery
What is the underlying pathology for dissecting aneurysm and where is it normally found?
Marfan’s (non-inflammatory medial disease)
aorta and main branches
What is the underlying pathology for capillary micro aneurysm and where is it normally found?
hypertension
pericyte loss in diabetes
cerebral caps
retinal caps
What is the underlying pathology for myocytic aneurysm and where is it normally found?
infection and septic emboli
any vessel
What are the consequences of aneurysms?
may be asymptomatic can rupture causing life-threatening haemorrhage compression of adjacent structures tissue/organ ischaemia thrombosis/embolism
What is seen on the picture?
atheromatous aneurysm in abdominal aorta
What is seen in the picture?
berry aneurysm in circle of willis
What is seen in the picture?
ruptured abdominal aortic aneurysm
dark, porridge material lining aneurysm is thrombus
What is myocarditis?
inflammation of the myocardium
What are the 5 main causes of myocarditis?
viral bacterial parasitic ionising radiation (inc therapy) drugs
What viral causes are there for myocarditis?
caxsackie
ECHO
adenoviruses
What bacterial causes are there for myocarditis?
diphtheria
meningococcus
What parasites cause myocarditis?
trypanosomiasis
Chagas’ disease
What drug can cause myocarditis?
adriamycin
What is pericarditis?
inflammatory reaction in visceral and/or parietal layers of pericardium
What are the causes of pericarditis?
viral bacterial TB post MI post surgery Dressler's syndrome carcinomatous uraemic
What classifies a serous pericarditis?
clear, straw-coloured
high specific gravity
high protein content
What classifies a serofibrinous pericarditis?
clumps of fibrin mixed in fluid
What is a purulent or supprative pericarditis?
frank pus
What is a blood-stained pericarditis suspicious of?
mlignancy
What is caseous pericarditis?
fungal/mycobacterial infection
What can happen when a caseous pericarditis is healing?
fibrotic obliteration of pericardial space (constrictive pericarditis)
What must happen with any pericarditis?
aspirate submitted to cytological lab
What are end results of shock?
hypotension
impaired tissue perfusion
cellular hypoxia
What are the 3 categories of shock?
cardiogenic
hypovolaemic
septic
What happens the brain, heart, kidneys, lungs, liver and GI tract in shock?
- neuronal damage
- focal/widespread necrosis (sub-endocardial region)
- acute tubular necrosis
- diffuse alveolar damage
- fatty change, zone 3 necrosis
- haemorrhagic enteropathy
