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Source: Veverka A and Crouch MA, Infective Endocarditis. In: DiPiro, JT, Talbert RL, Yee GC, Matzke GR, Wells BG, Posey LM. Pharmacotherapy: A Pathophysiologic Approach. 8th edition. Accessed June 23, 2012.

  • Inflammation of endocardium, membrane lining chambers of heart and covering cusps of heart valves.
  • Infective endocarditis (IE) refers to infection of heart valves by microorganisms, primarily bacteria.
    • Acute bacterial endocarditis is fulminating infection associated with high fevers, systemic toxicity, and death within days to weeks if untreated.
    • Subacute infectious endocarditis a more indolent infection, usually occurring in setting of prior valvular heart disease.

  • Majority of IE cases due to streptococci, staphylococci, and enterococci (Table 1).

Table 1. Etiologic Organisms in Infective Endocarditis

  • Most commonly develops via hematogenous spread.
    • Endothelial surface of heart damaged.
    • Platelet and fibrin deposition occurs on abnormal epithelial surface.
    • Organisms colonize endocardial surface.
      • Bacteremia results from trauma to mucosal surface with high concentration of resident bacteria (e.g., oral cavity, gastrointestinal [GI] tract)
    • “Vegetation” of fibrin, platelets, and bacteria forms on endothelial surface.
      • Bacteria protected from antibiotics and host defenses.
      • Valvular tissue may be destroyed.
      • Abscesses may develop in valve.
      • Friable vegetation (septic emboli) may travel to other organs, resulting in infarction or abscesses.

  • Antimicrobial prophylaxis used to prevent IE in patients at high risk undergoing procedures that cause transient bacteremia.
  • Issues to consider in prevention
    • Types of patients at risk
      • Prosthetic cardiac valves
      • Previous IE
      • Congenital heart disease
      • Cardiac transplant patient who develops cardiac valvulopathy
    • Procedures causing bacteremia
      • Dental procedures involving manipulation of gingival tissue of periapical region of teeth or perforation of oral mucosa.
    • Organisms most likely to cause IE
    • Pharmacokinetics, spectrum, cost, and ease of administration of available agents

  • Presence of prosthetic valve (highest risk)
  • Previous endocarditis (highest risk)
  • Congenital heart disease
  • Chronic intravenous access
  • Healthcare-related exposure
  • Acquired valvular dysfunction
  • Hypertrophic cardiomyopathy
  • Mitral valve prolapse with regurgitation
  • Age >50 years
  • History of IV drug abuse
  • Diabetes
  • Long-term hemodialysis
  • Poor dental hygiene

  • Highly variable and nonspecific
  • Fever most common finding.

Signs and Symptoms

  • Clinical signs prevalent in subacute illness (stigmata of endocarditis).
    • Osler nodes
    • Janeway lesions
    • Splinter hemorrhages
    • Petechiae
    • Clubbing of fingers
    • Roth’s spots
    • Emboli
    • Heart murmur
  • Symptoms
    • Fever
    • Chills
    • Weakness
    • Dyspnea
    • Night sweats
    • Weight loss
    • Malaise

Means of Confirmation and Diagnosis

  • Echocardiography to determine presence of valvular vegetations plays key role

Laboratory Tests

  • Complete blood count (CBC)...

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