Infective Endocarditis & Rheumatic Fever

• What is rheumatic fever?

  - A multisystem disease which occurs after a group A streptococcal infection

  
  

  - Affects heart, skin, joints and central nervous system
• Describe the aetiopathogenesis of rheumatic fever.

  Occurs after Group A, beta haemolytic streptococcal infection

  
• What are the risk factors for rheumatic fever?

  - Patients from low socio-economic groups

  - Overcrowded conditions

  - HLA DR4 positive
• How does rheumatic fever occur?

  Occurs after repeated oropharyngeal streptococcal infections causing an exaggerated B lymphocyte response.

  
  

  Streptococcal antigens cross react with connective tissue
• What might people with rheumatic fever develop?

  Vasculitis affecting the connective tissue (inflammation of vessel walls)

  
  

  Aschoff's body, consisting of an aggregate of large cells with polymorphs & basophils around a vascular fibrinoid core

  
  

  Pancarditis with the endocardium being the most severely involved (inflammation of all walls of the heart)
• How do you make a diagnosis of rheumatic fever?

  -Duckett-Jones criteria

  
  

  -Presence of 2 major & 1 minor criteria indicates high probability of rheumatic fever

  
• What is the prevalence of polyarthritis after the strep sore throat & what does it affect?

  Polyarthritis occurs in 80-90% of patients but the arthritis is migratory & lasts for 4-6 weeks

  
  

  It mainly affects the large joints such as the hip, knee, ankle, elbow & shoulder

  
  

  The pain may last for a week in any particular joint
• Describe carditis in rheumatic fever. (MAJOR)

  Occurs in 40-50% of patients

  
  

  Happens 2 weeks after polyarthiritis and involves all the cardiac tissue

  
  

  Lasts 3-6 months

  
  

  Clinical features vary, it may be asymptomatic or may be present with congestive cardiac failure.

  
  

  Asymptomatic cases are usually only recognised after the presentation of other clinical signs or cardiomegaly on the chest X-Ray

  
• Describe pericarditis in rheumatic fever. (MAJOR)

  Occurs in 5-10% of patients

  
  

  Inflammation of cardiac pericardium

  
  

  Presents with fluid in the pericardial space and may give rise to an intermittent pericardial rub

  
• Describe myocarditis in rheumatic fever. (MAJOR)

  - All of myocardium may be involved

  
  

  - Patients present with left ventricular failure which may lead to right ventricular failure and subsequent congestive cardiac failure

  
• Describe endocarditis in rheumatic fever. (MAJOR)

  - inflammation of inner lining of the heart chambers

  
  

  -Mitral valve is most commonly affected

  
  

  -May occur alone or in association with the aortic valve failure

  
  

  -Mitral + aortic valve disease = fulminant (associated with high mortality rate)

  
• Describe chorea in rheumatic fever. (MAJOR)

  - Late symptom

  
  

  - Involuntary movement of face and limbs

  
  

  -Disappears during sleep

  
  

  -occurs in 10% of patients

  
• Describe subcutaneous nodules/erythema nodusum in rheumatic fever. (MAJOR)

  - Subcutaneous nodules = rare

  - Occur over bony prominence

  
• Describe erythema nodusum in rheumatic fever. (MAJOR)

  - May also occur over the shins

  
  

  - Larger and more painful than subcutaneous nodules

  
  

  -Deep pink/Red

  
  

  -Nodules are tender on palpating

  
• Describe erythema marginatum in rheumatic fever:

  - Occurs in 65% of patients

  
  

  - Painless and non-pruritic rash (not itchy)

  
  

  -It has a serpinginous edge with a fading centre and spreads over the trunk and limbs

  
• What is infective endocarditis (IE)?

  Infection of the endocardial surface (inner lining) of heart or valves

  
  

  Usually bacterial, but occasionally can be fungale
• What is the morbidity & mortality rate for IE?

  Significant (20-30%)
• What is the annual incidence of IE in the UK?

  6-7 per 100,000 (possibly rising?)
• Why could incidence of IE be possibly rising?

  Increasing no. of elderly ppl (& hence abnormal/prosthetic valves)

  
  

  Increasing no. of invasive procedures, both diagnostic & therapeutic

  
  

  Increased no. of children with CHD (congenital heart disease) survive

  
  

  Increase in IV drug abuse
• What is endocarditis usually a consequence of? (2 factors)

  - Abnormal cardiac endothelium facilitating bacterial adherence and growth

  
  

  -Presence of organisms in the blood
• Describe the aetiopathogenesis of IE.

  1. Abnormal endothelium = creates non-laminar blood flow, promoting fibrin and platelet deposition

  
  

  2. Due to fibrin and platelet deposition, Small thrombi develop and allow organisms to adhere and grow

  
  

  - Leads to characteristic infected vegetations

  
• What do a growing number of patients with IE have?

  No definable underlying cardiac lesion

  
  

  e.g. patients over 65 with minor degenerative lesions or IV drug users with periodic introductions of foreign material who have undetectable lesions serving as a nidus
• What are the primary microorganisms involved in IE?


  Streptococci(63%)Viridans group (50%)Staphylococci (26%)Fungi (4%)

  Staphylococcus Aureus - from body

  Viridans - from mouth

  
• In what percentage of IE patients is a blood culture negative and why?

  -5-10%, possibly due to previous antibiotic therapy

  
  

  -Fastidious organisms (organisms that are complex and require specific nutritional requirements) that fail to grow in normal blood culture
• What are the clinical features of IE (1)?

  EARLY : Fever, sweats, loss of appetite, weight loss, malaise

  
  

  LATE : splenomegaly (enlargement of spleen), clubbing (bulbous enlargement of end of finger), anaemia

  
• What are the clinical features of IE, (2):

  - Septic arthritis, osteomyelitis, splenic abscess

  
  

  - CNS - meningitis, military brain abscess, TIA, stroke

  
• What investigations would you carry out in a patient with suspected IE?

  - Urine testing ( looking for microscopic haematuria)

  
  

  -Blood investigations (examples in the picture)

  
  

  -Chest radiograph (signs of heart failure)

  
  

  -Electrocardiogram

  
  

  -ECG

  
• What treatment options are possible for patients with IE?

  Drug therapy

  Surgery
• Parenteral route:


  taken into the body or administered in a manner other than through the digestive tract
• When would IE be treated with surgery?

  There are several situations when surgery is indicated:

  
  

  Extensive damage to a valve

  
  

  Infection of prosthetic material

  
  

  Worsening renal failure

  
  

  Persistent infection but failure to culture an organism

  
  

  Embolisation

  
  

  Large vegetations
• What is the prognosis for someone with IE?

  Mortality rate is 15-30%

  
  

  PROGNOSIS IS WORSE WHEN:

  
  

  - Organisms cannot be identified

  
  

  - Cardiac failure is present

  
  

  - Infection occurs on a prosthetic valve

  
  

  -Microorganisms found are resistant to therapy.
• What are the NICE guidelines for prophylaxis against IE?

  - This is to reduce the risk of antibiotic resistance

  
• What should healthcare professionals offer people with increased risk of IE?

  
• What pharmacotherapy is recommended for a patient with IE?

  It's treated with bactericidal antibiotics chosen on the basis of blood culture and antibiotic sensitivity assessment

  
  

  The treatment should continue for 4-6 weeks & at least the first two weeks should be parenteral