Infective endocarditis and rheumatic fever Flashcards
What is rheumatic fever? What parts of the body does it affect? (4)
It is a multisystem disease which occurs after a group A streptococcal infection. It affects the heart, skin, joints and CNS
What bacteria cause rheumatic fever?
Group A, beta heamolytic streptococci
How long is the latent period for rheumatic fever?
2-6 weeks
What are the risk factors for rheumatic fever? (4)
Patients from low socio-economic groups
Overcrowded conditions
HLA DR4 positive
When does rheumatic fever occur?
Occurs after repeated oropharyngeal streptococcal infections causing an exaggerated B lymphocyte response
In rheumatic fever, what cross-reacts with connective tissue?
Streptococcal antigens
Rheumatic fever causes Vasculitis - what is this? What does it affect in rheumatic fever?
Vasculitis means inflammation of the blood vessels. It affects the connective tissue in rheumatic fever
What microscopic structures would be visible when looking at a patient with rheumatic fever
Aschoff’s body - this is an aggregate of large cells with polymorphs and basophils around a vascular fibrinoid core
Rheumatic fever causes pancarditis - what is this?
What part of the body is most severely involved in this?
Pancarditis is inflammation of the heart.
The endocardium is the most severely involved
Chronic rheumatic fever may develop in what percentage of patients with acute rheumatic fever?
50%
What is the percentage of mortality in patients with rheumatic fever and carditis?
1%
What criteria is used when trying to diagnose rheumatic fever?
Duckett-Jones Criteria
What criteria combination indicates a high probability of rheumatic fever?
2 major criteria and one minor criteria
Name some examples of major criteria for rheumatic fever?
Carditis, polyarthritis, erythema marginatum ( rare skin rash that spreads on the trunk and limbs), subcutaneous nodule, chorea (movement disorder that causes involuntary, irregular, unpredictable muscle movements)
Name some examples of minor criteria for rheumatic fever?
Fever Arthralgia (joint stiffness) Previous rheumatic fever Raised acute phase proteins ECR (erythrocyte sedimentation rate), CRP (C-reactive protein), Ferritin Prolonged P=R interval on ECG
What is polyarthritis?
It is when 5 or more joints are affected with arthritis
In what percentage of patients with rheumatic fever suffer with polyarthritis?
80-90%
What may be the first clinical manifestation of rheumatic fever after the streptococcal sore throat?
Polyarthritis
How long does polyarthritis last for?
4-6 weeks
What joints are mainly affected by polyarthritis?
Knee, ankle, elbow, hip and shoulder
How long may the pain last for in a particular joint when suffering with polyarthritis?
A week
What is carditis?
Carditis is the inflammation of the heart
In what percentage does carditis occur in rheumatic fever patients?
40-50%
How soon after polyarthritis does carditis occur in rheumatic fever patients?
2 weeks
How long does carditis last for in RF patients?
3-6 months
What are the clinical features of carditis in RF patients?
They may vary - they may not have any symptoms (be asymptomatic) or they may present with congestive heart failure
If a RF pt has a symptomatic carditis, how may this be recognised??
After other clinical signs have presented
or
Cardiomegaly on a chest x-ray
What is pericarditis?
Inflammation of the pericardium
How does pericarditis present?
Presents with fluid in the pericardial space and may give rise to an intermittent pericardial rub
What is myocarditis?
It is the inflammation of the heart muscle (myocardium) - all of the myocardium may be involved
How may patients with myocarditis present?
Left ventricular failure which may lead to right ventricular failure and subsequent congestive cardiac failure
What is endocarditis?
It is a rare and potentially fatal infection of the inner lining of the heart
Which part of the heart is most commonly affected by endocarditis?
Mitral valve.
It may occur alone or in association with the aortic valve failure.
What is it called when mitral and aortic valve endocarditis disease occur together?
Fulminant
This is associated with a high mortality rate
What is valvulitis?
It is the inflammation of the heart valves - this is a common complication of acute rheumatic fever
What does valvulitis result in?
Results in nodules on the mitral and aortic valves resulting in murmurs
What clinical manifestation indicates late stages of RF?
Chorea
How long after other features of RF may chorea occur?
4-6 months
In what percentage of RF patients does chorea occur?
10%
What name is given to involuntary movements of face and limbs, that disappears during sleep?
Syndenham’s chorea
What is another name for Sydenham’s chorea?
St Vitus’ dance
What type of nodules are rare in RF patients?
Subcutaneous nodules
What do subcutaneous nodules look like?
Small (up to 0.5cm) are non-tender, mobile and firm
Occur over bony prominence
What is the name for nodules that are larger that subcutaneous nodules that are painful?
Where do these occur and how do they appear?
Erythema nodosum
Over shins
Appear as deep pink/red nodules that are tender on palpation
What type of erythema occurs in 65% of RF patients?
Erythema marginatum
What is invariably (always) seen in association with carditis? in patients with RF
Erythema Marginatum
What does an erythema marginatum rash look like?
Serpiginous edge (wavy) with a fading centre, and spreads over the trunk and limbs.
Painless and non-itchy (non-pruritic)
What is infective endocarditis?
Infection of the endocardial surface of heart or valves - usually bacterial (occasionally fungal).
What is the morbidity and mortality rate of infective endocarditis (IE)?
20-30%
What is the annual incidence in the UK for IE?
6-7 per 100,000
Give 4 suggestions as to why the incidence of IE may be rising?
- Increasing number of elderly people (& hence abnormal/prosthetic valves)
- Increasing number of invasive procedures both diagnostic and therapeutic
- Increased number of children with CHD survive
- Increase in IV drug abuse
Endocarditis is usually of a consequence of which 2 factors?
- Abnormal cardiac endothelium facilitating bacterial adherence and growth
- Presence of organisms in blood
Give 3 examples of a bacterial source that may cause endocarditis
Infected needle Open wound Dental procedure Cardiac Device Surgery Intravascular catheter
What is the bacteria that’s most likely to cause endocarditis?
Staph aureus
What in the heart may provide an abnormal substrate for endocarditis to occur?
Prosthetic valve - sutures and endothelial damage
Native Valve damage - endothelial damage (exposed collagen)
What is the significance of abnormal endothelium in the occurrence of endocarditis?
Non-laminar blood flow (turbulent), promoting fibrin and platelet deposition
This creates small thrombi (clots) which allow organisms to adhere and grow
Leads to characteristic infected vegetations
Name (in order) the top 4 organisms that are involved in the pathogenesis of IE
Streptococci 63%
Viridans groups 50%
Staphylococci 26%
Fungi 4%
When trying to culture the organisms that cause IE - the culture is negative in approx 5-10%, why is this? (2)
- Possibly due to previous AB therapy
- Fastidious organisms that fail to grow in normal blood cultures
What are the early signs of infection in IE? (5)
Fever, sweats, loss of appetite, weight loss, malaise
What are the late signs of infection in IE? (3)
Splenomegaly, clubbing, anaemia
What are the 3 signs of heart disease in IE?
Development of new murmur
Change to an existing murmur
Heart failure
What are signs of embolism in IE?
Septic arthritis
Osteomyelitis
Splenic abscess
CNS - meningitis, miliary brain abscess, TIA (transient ischemic attack), stroke
What may you see that may indicate that a patient has IE?
On the skin: Osler’s nodes (painful, red, raised lesions found on the hands and feet), splinter haemorrhage (tiny blood spots that appear underneath the nail)
In urine: blood (haematuria - renal issue)
Eyes - Roth’s spots (non-specific red spots with white or pale centres, seen on the retina)
What are the 6 investigations you can do to investigate IE?
- Urine testing: microscopic haematuria
- Blood cultures: positive in 75% of cultures
- Bloods: FBC (raised white cell count), ESR/CRP (raised), LFT (mild disturbance, alkaline phosphatase raised), serum immunoglobulins (raised), complement and C3 (decreased).
- Chest radiograph: cardiomegaly and signs of heart failure
- Electrocardiogram
- Echocardiogram
Outline IE treatment with drug therapy
Drug therapy: pharmacotherapy
- Bactericidal antibiotics chosen on basis of blood culture and antibiotic sensitivity assessment
- Treatment should continue for 4-6 weeks and at least the first 2 weeks should be parenteral (not delivered via GI tract - i.e. IV)
Name the 2 ways IE can be treated
Drug therapy
Surgery
Outline when surgery may be used to treat IE (6)
Extensive damage to valve. Infection damage to a valve. Worsening renal failure. Persistent infection but failure to culture an organism. Embolisation. Large vegetations
Give 4 situations where prognosis for IE surgery may be worse
- organism cannot be identified
- Cardiac failure is present
- Infection occurs on prosthetic valve
- Microorganisms found are resistant to therapy
When would antibiotic prophylaxis NOT be recommended (according to NICE guidelines)? (4)
- People undergoing dental procedures
- People undergoing procedures in the upper and lower GI tract
- People having procedures in Genitourinary tract: including urological, gynaecological and obstetric procedures and childbirth
- People having procedures in upper and lower resp tract: including ear, nose and throat procedures and bronchoscopy.
What else should not be offered as prophylaxis against IE to people at risk when undergoing dental procedures?
Chlorhexidine mouthwash
What puts a patient more at risk of IE? (6)
- Structural cardiac defects
- Acquired valvular heart disease with stenosis or regurgitation
- Hypertrophic cardiomyopathy
- Previous infective endocarditis
- Structural congenital heart disease (including corrected conditions)
- Valve replacement
What advice and information should be given to patients that are of increased risk? (4)
- Benefits and risks of AB prophylaxis - give explanation why AB prophylaxis is no longer routinely recommended
- Importance of maintaining good oral health
- Symptoms that may indicate IE and when to seek expert advice
- The risks of undergoing invasive procedures, including non-medical procedures such as body piercing or tattooing.