Infective Endocarditis

Infective Endocarditis-Cardiology

  1. Definition – Infective Endocarditis is the proliferation of micro organisms on the endothelium of the heart.
    Vegetation – mass of platelets, fibrin, micro colonies of micro organism and scanty inflammatory cells. They are bulky,
    friable, irregular, and multiple, occur along the cusp.
  2. Classification
    a. Acute = 50% of all endocarditis occurs on normal valves. It follows an acute course and presents with acute heart
    b. Sub Acute = Endocarditis on abnormal valves tends to run a subacute course.
  3. Any cause of bacteriemia exposes valves to the risk of bacterial colonization (dentistry; UTI; urinary catheterization;
    cystoscopy; respiratory infection; endoscopy colon cancer; gall bladder disease; skin disease; IV cannulation; surgery;
    abortion; fractures).
  4. Predisposing cardiac lesions: aortic or mitral valve disease; tricuspid valves in IV drug users; coarctation; patent ductus
    arteriosus; VSD; prosthetic valves. Endocarditis of prosthetic valves may be early (acquired at the time of surgery, poor prognosis) or ‘late’ (acquired hematogenously).
  5. HACEK – They are fastidious, slowly growing, gram negative and CO2 for growth .
  6. Etiology
    a. Native valve endocarditis: Mitral valve is the most common valve involve.
    Causative organism
    i. Most common cause in native valve = Staph aureus
    ii. Streptococci viridans
    iii. Streptococcus bovis (Polyp, colon tumors)
    iv. Enterococci
    v. HACEK organisms (Hemophilus, Actinobacillus, Cardiobacterium, Eikenella, Kingella)
    Important Points Hemophilus influenzae is not a part of HACEK group. H. aphrophilus and H. parainfluenzae are the most
    common Haemophilus species isolated from case of HACEK endocarditis.
    b. Prosthetic valve endocarditis (Most common valve involved is aortic valve)
    i. Within 2 months of surgery = staph aureus
    ii. After 2 months of surgery = coagulase negative staphylococci (CoNS).
    Note: A patient has prosthetic valve replacement and he develops endocarditis 8 months later. Organism
    responsible is CoNS
    c. Endocarditis in I.V. drug abusers (Most common valve involve is = tricuspid)
    i. Commonest– Staph aureus
    ii. Pseudomonas aeruginosa
    Medicine Simplified DBMCI
    iii. Candida
    iv. Polymicrobial infection is more common.
    v. Pseudomonas causes endocarditis in IV drug abuser.
  7. Culture negative endocarditis
    a. Pyridoxal requiring streptococci (Abiotrophia) b. HACEK c. Bartonella
    d. Tropheryma whippelii e. Libmann sack endocarditis f. Marantic endocarditis.
  8. Fever, rigors, night sweats, malaise, weight loss, anaemia, splenomegaly , and clubbing .

    Cardiac lesions: Any new murmur, or a change in the nature of a pre-existing murmur.
  9. Vegetations may cause valve destruction, and severe regurgitation, or valve obstruction.
  10. An aortic root abscess causes prolongation of the P-R interval, and may lead to complete AV block.
  11. LVF is a common cause of death.
  12. Immune complex deposition:
    a. Vasculitis.
    b. Microscopic hematuria , is common in glomerulonephritis
    c. Acute renal failure may occur.
    d. Roth spots (boat-shaped retinal hemorrhage with pale centre;
    e. Osler’s nodes (painful pulp infarcts in fingers or toes)

Vascular phenomena:
Splinter hemorrhage
hemorrhages are tiny
blood hemorrhages that
tend to run vertically
under the nails.
Medicine Simplified DBMCI
a. Emboli may cause abscesses .
b. In right-sided endocarditis, pulmonary abscesses.
c. Janeway lesions (painless palmar or plantar macules).
d. Splinter hemorrhages (on finger or toe nails);

Complications of Endocarditis
a. Heart failure
b. Embolic phenomena
c. conduction abnormality
d. CVA
e. Meningitis
f. Mycotic aneurysm (Note: they are due to bacteria and not due to fungus!!!)
g. VSD
h. Perforation of aorta.

a. Blood cultures: 3 blood cultures sample should be taken
b. Blood tests: Normochromic, normocytic anaemia, neutrophil Leucocytosis, high ESR/CRP.
c. Echocardiography Transthoracic Echo (TTE) may show vegetations, but only if >2mm.
d. Transesophasial Echo (TEE) is more sensitive, and better for visualizing mitral lesions and possible
development aortic root abscess.
e. Diagnosis The Duke criteria for definitive diagnosis of endocarditis are given.
Criteria of How to diagnose: Definite infective endocarditis: 2 major or 1 major and 3 minor or all 5 minor criteria (if no
major criterion is met).
Extra Edge:
a. Janeway lesions are non-tender, small erythematous or haemorrhagic macular or nodular lesions on
the palms or soles only a few millimeters in diameter that are indicative of infective endocarditis. Pathologically,
the lesion is described to be a microabscess of the dermis. They are caused by septic emboli which deposit
bacteria, forming microabscesses.
b. Osler’s nodes and Janeway lesions are similar, but Osler’s nodes present with tenderness and are of
immunologic origin
c. Roth’s spots are retinal hemorrhages with white or pale centers.
d. Splinter hemorrhages (or haemorrhages) are tiny blood clots that tend to run vertically under the nails

a. Antibiotics:
i. Empirical therapy:
• Benzylpenicillin + gentamicin, ii. If acute, add flucloxacillin
ii. Definite therapy : If organism grows in blood culture.
• Enterococci: amoxicillin gentamicin.
• Streptococci.’ Benzylpenicillin for 2-4wks; then amoxicillin for 2wks.
• Staphylococci. flucloxacillin + gentamicin.
• Coxiella: doxycycline indefinitely + co-trimoxazole, or rifampicin or ciprofloxacin.
b. Consider surgery if: heart failure, valvular obstruction; repeated emboli; fungal endocarditis; persistent
bacteriemia myocardial abscess; unstable infected prosthetic valve.
Janeway lesions
Medicine Simplified DBMCI

Prognosis 30% mortality with staphylococci; 14% with bowel organisms; 6% with sensitive streptococci

a. Amoxicillin 2g orally 1h before dentistry. This suitable for those who have not received penicillin in the last month,
including those with prosthetic valves (If penicillin allergic, clindamycin 600mg orally 1 hrs before surgery). Infective Endocarditis b. If past endocarditis, IV gentamicin and amoxicillin.

Risk of infective endocarditis in various lesion:
High Risk Moderate Risk Low Risk
Prosthetic heart valve, Tetralogy of Fallot, PDA, Coarctation of aorta MVP + M.R. ASD
VSD, Mitral regurgitation MVP without MR

High-Risk Cardiac Lesions for Which Endocarditis Prophylaxis Is Advised before Dental Procedures
a. Prosthetic heart valves
b. Prior endocarditis
c. Unrepaired cyanotic congenital heart disease, including palliative shunts or conduits
d. Completely repaired congenital heart defects during the 6 months after repair
e. Incompletely repaired congenital heart disease with residual defects adjacent to prosthetic material
f. Valvulopathy developing after cardiac transplantation

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