Heart Disorders 2 Flashcards
What is Acute Rheumatic Fever?
an acute, immunologically mediated, multi-system inflammatory disease
what is rheumatic heart disease?
valvular disease resulting from chronic valve damage as a result of acute rheumatic fever
aka rheumatic valve disease
what is the difference between rheumatic fever and rheumatic heart disease
rheumatic fever is an inflammatory disease
rheumatic heart disease is a result of rheumatic fever, leading to chronic valve damage
aetiology of rheumatic fever
commonly from group A streptococcal pharyngitis
pathogenesis of rheumatic fever
- a hypersensitive response - antibody and T cell
- antibody response against M proteins of streptococci
- CD4 + T cells specific to streptococcal peptides
what are the key clinical features of rheumatic fever (5)
- migratory polyarthritis of the large joints
- pancarditis
- skin lesions
- subcutaneous nodules
- CNS - cause Sydenham chorea = involuntary movements
- 10 days-6 weeks post infection
what is migratory polyarthiritis?
one large joint becomes painful and swollen for a period of days then subsides
- happens to another large joint
- repeats
what is Pancarditis or acute rheumatic carditis?
affecting all three layers of the heart
- can cause cardiac dilation or heart failure
what is acute rheumatic carditis? what is affected?
when acute rheumatic fever affects the heart
- can affect the three layers of the heart
= pericardium
= myocardium
= endocardium
what are the 3 layers of the heart.
pericardium
myocardium
endocardium
with the 3 layers of the heart, what can be a result of acute rheumatic carditis?
pericardium = pericarditis
myocardium = myocarditis
endocardium = endocarditis
what is a characteristic feature of myocarditis?
Aschoff bodies - clumps of macrophages recruited into the area of muscle damage due to autoimmune response
where can Aschoff bodies be found?
in all three cell layers of the heart
= pancarditis
what is the diagnostic criteria of rheumatic fever
using the Jones Criteria
- must have evidence of group A strep infection
patient symptoms
- 2 of the major criteria or
- one major and 2 minor
what comes under major diagnostic criteria for acute rheumatic fever? (5)
carditis
polyarthritis
chorea - abnormal movements
erythema marginatum
subcutaneous nodules
what comes under minor diagnostic criteria for acute rheumatic fever? (5)
fever
arthralgia
previous rheumatic fever or rheumatic heart disease
acute phase reactions
prolonged PR interval
pathogenesis of rheumatic heart disease (6)
- cardiac hypertrophy
- cardiac dilation
- heart failure
- arrhythmias
- veruccae aka vegetations
- mitral stenosis
what is mitral stenosis?
narrowing of the mitral valve, found on the left side
what is the most likely cause of mitral stenosis?
rheumatic heart disease
what are veruccae? - rheumatic heart disease
nodules found in areas of valve damage
what valves are involved in rheumatic heart disease?
mostly only mitral valve
25% aortic valve - usually wear and tear
tricuspid/pulomonary valves are uncommon
what are the key clinical features of rheumatic heart disease (2)
-permanent and cumulative valve damage
- mitral stenosis - looking like a fish mouth or buttonhole
what is the diagnostic criteria of rheumatic heart disease
relies on the Jones Criteria
what is endocarditis? how does it usually present?
inflammation of the endocardium
- usually get vegetation lesions on the valve
what are the 2 forms of endocarditis?
infective endocarditis
non-infective endocarditis
define infective endocarditis
a clinically serious infection
- a microbe colonises or invades the heart valves or heart chamber
what are the two types of infective endocarditis?
acute infective endocarditis = the worse one
sub-acute infective endocarditis
what is the cause and 3 effects of acute infective endocarditis?
highly virulent organism
necrotising, ulcerative, destructive lesions
how is acute infective endocarditis treated?
its difficult to cure
- antibiotics and surgery
- death is frequent
what is the cause of subacute infective endocarditis? how it is treated?
lower virulent organisms
less destructive
cured with long-term antibiotics
what are the risk factors for infective endocarditis?
4 high risk factors
5 mid risks
1 low risk
high risk
- artificial heart valves
- prior episodes
- complex cardiac defects
- surgically constructed shunts
mod risk
- septal defects
- hypertrophic cardiomyopathy
- valvular dysfunction
- MVP with mitral regurgitation
low risk
- innocent murmur
- organisms in bloodstream = infection
- cardiac vascular abnormalities = abnormal flow = promotes adherence and growth
- rheumatic heart disease - damages the valves, disrupts blood flow
what is polymicrobial infective endocarditis? what is a common risk factor and pathogenesis?
infection due to multiple organisms
predominant risk factor = IV drug use
1/3 die
what are the clinical features for infective endocarditis?
can be more than one valve
bulky, crumbles away vegetation
can erode and lead to access = ring abscess
can embolise and be septic - contain large numbers of virulent organisms
fever
non-specific symptoms - loss of weight
murmurs - from new valvular defect or pre-existing abnormality
how is infective endocarditis diagnosed?
Duke Criteria
what is the pathogenesis of infective endocarditis?
any route of bacteria into blood
- dental abnormalities
- wounds
- IV needles
- streptococcus viridans from the mouth
- staph aureus from the skin
- coagulase-negative staphlococci - usually heart valve
- HACEK group - all commensals in oral cavity = unusual
what does it mean that endocarditis is culture negative?
you cannot isolate the causative agent
what can be the complications/features of infective endocarditis? FROM JANE
F - fever
- Roth Spots
- retinal haemorrhage in the eye
- Osler’s Nodes
- subcutaneous nodules in the pulp of digits
M - murmurs
- Janeway Lesions - erythematous or haemorrhage non-tender lesions on palms or soles
- Anaemia
- Nail splinter haemorrhgaes
- Emboli (septic)
what is the treatment for infective endocarditis?
high concentration of IV antibiotics
4-6 weeks
what are the clinical guidelines for treating patients with all above conditions?
there is no clear association with dental procedures
- brushing has more risk than procedures
- antibacterial prophylaxis and chlorhexidine mouthwash are not recommended
- maintain high standard of hygiene
-report any unexplained illness after dental treatment, should be investigated promptly
