2. Definition
Infection of the endocardial surface of heart characterized by
- Colonization or invasion of the heart valves (native or
prosthetic) or the mural endocardium by a microbe,
- leading to formation of bulky, friable vegetation composed
of thrombotic debris and organisms
- often associated with destruction of underlying cardiac
tissue.
4. Classification
ACUTE ENDOCARDITIS SUBACUTE ENDOCARDITIS
• Destructive and tumultuous • Organisms of low virulence
infection, frequently of a causing infection in a
previously normal heart valve, previously abnormal heart,
with a highly virulent particularly on deformed
organism valves.
• Hematogenoulsy seeds • Disease appear insidiously and
pursue a protracted course of
• If untreated, leads to death weeks to month
within weeks
• Recover after appropriate
antibiotic treatment
6. Microbiology
• Staphylococcus aureus (35%) : Either healthy or deformed valves, IV drug
abusers (polymicrobial), devices
• Streptococcus viridans (32%) : Native but previously damaged/abnormal
valves
• Enterococci (8 %)
• CoNS - S. epidermidis (4%): Prosthetic valve endocarditis, devices
• G –ve bacilli of HACEK group (4%)
• Yeast and Fungi(1%)
• Culture negative endocarditis (5 %)
7. Pathogenesis
Portal of entry:
◦ Dental / Surgical Procedures
◦ Contamination by IV drug use
◦ Obvious infections (RS/Skin)
◦ Occult source from gut, oral cavity
◦ Trivial injuries.
◦ Intravascular catheter infection
◦ Nosocomial wounds
◦ Chronic invasive procedures
8. Endothelial Injury
Uninfected Platelet-Fibrin thrombus (NBTE)
Transient bacteremia and attachment at
NBTE
Proliferation and pro-coagulant state
Infected, friable, bulky vegetation
9. Morphology
• Friable, bulky vegetation containing fibrin, inflammatory cells, and microbes
• Aortic and mitral valves involved most commonly.
• Right side valve involvement in iv drug users.
10. Clinical features
Symptoms Constitutional symptoms
- Damage to intracardiac --- Cytokine release ?
structures
- Embolization of vegetation
fragments
- Hematogenous infection
- Immune complex
11. Sub-acute Endocarditis
• Persistent fever
• Constitutional symptoms
• New signs of valve
dysfunction
• Heart failure
• Embolic Stroke
• Peripheral arterial
embolism
• Other features
12.
13. Modified Dukes Criteria for diagnosis
of Infective Endocarditis
Definitive Endocarditis if,
- Two major or,
- One major and three minor or,
- five minor
Possible Endocarditis if,
- One major and one minor or,
- Three minor
14. Major Criteria
Positive blood culture
◦Typical organism from two cultures
◦Persistent positive blood cultures taken > 12 hours apart
◦Three or more positive cultures taken over more than 1
hour.
Endocardial involvement
◦Positive echocardiographic findings of vegetations
◦New valvular regurgitation
15. Minor Criteria
• Predisposition: Predisposing valvular or cardiac abnormality
• Intravenous drug misuse
• Pyrexia ≥38°C (≥100.4°F)
• Embolic phenomenon
• Vasculitic/ immunologic phenomenon
• Blood cultures suggestive: -organism grown but not achieving
major criteria
• Suggestive echocardiographic findings
17. .
Microbiology
Blood cultures:
Key diagnostic investigation in infective endocarditis.
Isolation of microorganism from culture is important for
diagnosis and also for treatment.
At least 3 sets of samples should be taken from different
venepuncture sites over 24 hours.
18. Serology
Can be sent when the diagnosis is suspected and the
cultures are negative.
They aid in cases where the organisms will not grow in
blood cultures(Coxiella,Legionella,Bartonella)
ECG
To detect complications like MI,conduction
abnormalities.
CHEST X RAY
19. .
Echocardiography
It can identify the presence and size of
vegetations,detect intracardiac complications and
assess cardiac function.
Transthoracic echocardiography is noninvasive and has
high specificity for visualising vegetations.
Transoesophageal echocardiography is more sensitive
than TTE.It can detect small vegetations,prosthetic
endocarditis and intra cardiac complications.
20. .
Complete blood counts
may show anamia and increased WBC counts.
Urea and Creatinine:
may be elevated due to glomerulonephritis
Liver biochemistry:
Serum alkaline phosphatase may be increased
Inflammatory markers
CRP,ESR are increased in infection .CRP also helps in
monotoring response to therapy.
Urine
proteinuria and hematuria occur frequently.
21. TREATMENT
Antimicrobial Therapy
Therapy requires identification of specific pathogen
and its susceptibility to antimicrobials.
Empirical therapy should be started as soon as
possible targeting most likely pathogens.
Bactericidal drugs should be used.
22. Resolution of fever occurs in 5 to 7 days.if fever
persists patient should be evaluated for complications
like paravalvular abscess and extracardiac abscess.
Serologic abnormalities resolve slowly and do not
reflect response to treatment.
23. Antibotic regimen for infective endocarditis
Streptococci
Benzyl penicillin (1.2g 4 hourly) 4-6 weeks
Gentamicin (1mg/kg 8-12 hourly) 4-6 weeks
Enterococci
o Ampicillin sensitive
Ampicillin (2 g 4 hourly) 4-6 weeks, and
Gentamicin (1mg/kg 8-12 hourly)
o Ampicillin resistant
Vancomycin(1g 12hourly) 4-6 weeks, and
Gentamicin (1mg/kg 8-12 hourly)
24. Staphycocci
oPenicillin sensitive
Benzyl penicillin I.V(1.2 g 4 hourly)
oPenicillin resistant but methicillin sensitive
Flucloxacillin I.V (2g 4 hourly )
oBoth penicillin and methicillin resistant
Vancomycin I.V (1g 12 hourly) and
Gentamicin
25. .
Surgery
Indications
patients with direct extension of infection to
myocardial structuires.
Prosthetic valve dysfunction.
Congestive heart failure.
Badly damaged valves.
IE caused by fungi or gram-ve or resistant organisms.
Large vegetations on echocardiography
Recurrent embolic attacks.
26. Prophylaxis
High risk category
prosthetic cardiac valves
Previous bacterial endocarditis,even in absense of
heart disease.
Complex cyanotic congenital heart disease(TGA,TOF)
Surgically constructed systemic pulmonary shunts.
27. Moderate risk category
Rheumatic and other valvular dysfunction
Congenital cardiac malformations
Hypertrophic cardiomyopathy
Mitral valve prolapse with valvular regurgitation
28. Regimen for IE prophylaxis
Standard oral regime
Amoxicillin 2 g 1hr before procedure
Inability to take oral medication
Ampicillin 2g IV or IM 1hr before procedure
Penicillin allergy
Clindamycin 600 mg
Clarithromycin 500 mg
Cephalexin 2 g.