infectious & rheumatic heart disese Flashcards
What is the definition of rheumatic fever?
Infection with Group A Streptococcus Pyogens (GAS) → autoimmune reaction
Develops 2-3 weeks after the onset of sore throat
What chronic condition is associated with rheumatic fever?
Rheumatic heart disease, characterized by chronic valvular abnormalities, mostly mitral stenosis (MS)
Incidence has fallen dramatically in industrialized countries
What pathological findings are seen in the heart during rheumatic fever that are indicative of an autoimmune reaction?
Aschoff’s bodies
What is the major diagnostic criteria of rheumatic fever?
J❤️nes
Joints: Polyarthritis of large joints; fleeting
Involves multiple joints, typically large ones
Cardiac: murmurs (mitral regurgitation or aortic regurgitation), congestive heart failure, pericarditis (pericardial rub)
Subcutaneous Nodules: over tendons/ joints/ bony prominences
Erythema marginatum: transient pink coalescent rings on trunk
Sydenham’s chorea: involvement of the central nervous system
Results in involuntary movements
What are the minor criteria for diagnosing rheumatic fever?
- Fever
- Elevated ESR or CRP or leukocytosis
- Prior history of rheumatic fever or rheumatic heart disease
- Prolonged PR interval on ECG
- Arthralgia
Minor criteria are less specific than major criteria
What is required for a diagnosis of rheumatic fever?
2 major criteria OR 1 major and 2 minor + throat culture growing GAS OR elevated anti-streptolysin O titers
Diagnostic criteria must be met for confirmation
What is the recommended treatment for rheumatic fever?
- Complete bed rest (especially for those with carditis)
- High-dose aspirin (to control arthritis, fever, and other acute symptoms)
- Penicillin (to eradicate residual streptococcal infection)
- Treatment monitored with CRP
- Prednisolone if cardiac involvement
- Treat valvular pathology
Management is crucial to prevent complications
What is the preventive measure for streptococcal pharyngitis?
Penicillin (erythromycin if allergic)
Prevention of rheumatic fever through treatment of infections
What is the duration of prevention for rheumatic fever with carditis and residual heart disease? (persistence valvular disease)
10 years or until age 40, whichever is longer
Duration is based on the risk of recurrence
What is the duration of prevention for rheumatic fever with carditis but no residual heart disease? (no persistence valvular disease)
10 years or until age 21, whichever is longer
Less duration compared to those with residual heart disease
What is the duration of prevention for rheumatic fever without carditis?
5 years or until age 21, whichever is longer
Shortest duration of prevention
What is the definition of infective endocarditis?
Infection of the endocardium or the vascular endothelium of the heart
What are the two types of infective endocarditis?
- Acute: Mostly by S. aureus, normal valve, fatal in <6 weeks if untreated
- Subacute: More common, Streptococcus viridians or Enterococcus, damaged valve, takes >6 weeks to cause death
What organism is commonly associated with infective endocarditis in a native healthy valve?
Staph. aureus
Which organism is associated with infective endocarditis in a native diseased valve?
Strept. viridians
What is the common organism causing early onset prosthetic valve infective endocarditis?
(< 60 days of surgery)
Staph. epidermidis (acquired in perioperative period)
What organism is responsible for late onset prosthetic valve infective endocarditis?
(> 60 days of surgery)
Streptococci (follows bacteremia)
Which organisms are commonly found in infective endocarditis among IV drug users?
- S. aureus mostly
- Enterococci
- Streptococci
- Fungi (Candida)
- Gram -ve rods (Pseudomonas)
usually are right-sided valves
What are the culture negative organisms associated with infective endocarditis?
- Coxiella burnetti
- Bartonella
- Chlamydia
- Legionella
What are some constitutional symptoms of infective endocarditis?
- Fever
- Weight loss
- Anemia
- Slight splenomegaly (important finding)
What rule must be followed when a new heart murmur is present with fever?
Must rule out infective endocarditis
What causes heart failure and murmurs in infective endocarditis?
Valve destruction due to vegetations made up of fibrin, platelets, and infectious organisms
What are Janeway lesions?
Painless vascular phenomena associated with infective endocarditis
What are some examples of metastatic abscesses in infective endocarditis?
- Brain
- Kidney
- Spleen
- Lungs (if right-sided)
what occurs with immune complex deposition?
- splinter hemorrhages (in nail beds)
- roth’s spots (in retina)
- osler’s nodes (painful)
- arthralgia
- glomerulonephritis with microscopic hematuria
What results with embolization of vegetations?
- janeway lesions (painless vascular phenomena)
- metastatic abscesses (brain, kidney, spleen, lungs)
What are some investigations used to diagnose infective endocarditis?
- Blood cultures (3 sets taken over 24 hours) - taken before antibiotics are started
- Serological tests for unusual organisms
- CBC: normocytic normochromic anemia, leukocytosis, raised ESR
- Echocardiography: Transthoracic and Transesophageal
- CXR: Heart failure or evidence of embolization
- ECG: MI or conduction defects
- Urinalysis: hematuria
- Raised serum Ig and low complement
What is the significance of taking blood cultures before starting antibiotics?
To ensure accurate identification of the causative organism
True or False: Transesophageal echocardiography is less sensitive than transthoracic echocardiography in the case of prosthetic valves.
False
Fill in the blank: The presence of _______ indicates a potential embolization to the coronary arteries.
MI
What is the typical anemia seen in infective endocarditis?
Normocytic normochromic anemia
What is raised in serum due to immune complex deposition in infective endocarditis?
Raised serum Ig and low complement
What is required for a definite diagnosis of infective endocarditis according to the Modified Duke Criteria?
2 Major Criteria OR 1 Major and 3 Minor OR 5 Minor OR direct evidence of infective endocarditis
Direct evidence includes vegetation histology or culture.
What is required for a possible endocarditis diagnosis?
1 Major and 1 Minor OR 3 Minor
What are the Major criteria for diagnosing infective endocarditis?
- 2 positive blood cultures for an organism known to cause IE
- Persistent bacteremia (2 +ve 12 hours apart or 3 of 4 +ve drawn over 1 hour)
- ECHO evidence (oscillating mass on valve, abscess, new valvular regurgitation, partial dehiscence of prosthetic valve)
What are the Minor criteria for diagnosing infective endocarditis?
- Predisposing factor (cardiac lesion, IV drug use)
- Fever > 38°C
- Evidence of emboli or vasculitis
- Immunological features (Osler node, nephritis)
- Echo of uncertain significance
- Serology for Q fever or Chlamydial infection
- Single +ve blood culture of uncertain etiology
What is the initial treatment protocol for infective endocarditis?
IV bactericidal Antibiotics for 2 weeks, then oral for 2-4 weeks.
What are the empirical antibiotics used for treating infective endocarditis?
Benzylpenicillin + gentamicin
if staphylococci are suspected then vancomycin + gentamicin.
What are the indications for acute valve replacement in infective endocarditis cases?
- Severe heart failure
- Worsening renal failure
- Extensive damage to the valve
- Prosthetic valve
Is prophylaxis indicated for patients diagnosed with infective endocarditis?
NOT INDICATED for patients when they are diagnosed.
What conditions require prophylaxis in patients with infective endocarditis?
And what drug is used
When the patient has BOTH a qualifying cardiac indication AND a qualifying procedure.
Amoxicillin.
If allergic to penicillin, give Clindamycin or azithromycin.
What are the cardiac indications for prophylaxis in infective endocarditis?
- Prosthetic heart valve
- History of infective endocarditis
- Transplanted heart with valvular disease
- Unrepaired cyanotic congenital heart disease
- Repaired congenital heart disease with prosthetic material within the first 6 months after procedure
- Repaired CHD with residual defects at the site of a prosthetic patch or device
What types of procedures require prophylaxis for infective endocarditis?
- Dental procedures involving manipulation of gingival tissue or periapical region
- Invasive respiratory tract procedures involving incision or biopsy of respiratory mucosa
- Surgical procedures involving infected skin or musculoskeletal tissue
Is prophylaxis required for genitourinary or gastrointestinal tract procedures in infective endocarditis?
No prophylaxis is required.
