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Flashcards in Endocarditis Deck (24):

What is rheumatic fever?

Systemic complication of pharyngitis due to Group A ß-hemolytic streptococci (GAS) 


What is the pathophysiology of rheumatic fever?

  • Molecular mimicry (type II hypersensitivity)
  • bacterial M protein resembles proteins in human cardiac tissue
  • Abs against M protein may also attack heart


What is the major criteria of diagnosing rheumatic fever?

  • J - joints
    • Migratory polyarthritis
    • Swelling and pain in a large joint that resolves within days followed my involvement with another large joint
  • O - heart
    • Pancarditis 
    • Inflammation at all layers of the heart
  • N - nodules
    • Subcutaneous nodules
  • E - erythema marginatum
    • Erythema marginatum
    • nonpruritic rash with eryhtematous borders 
    • Commonly involves trunk and limbs
  • S - Sydenum chorea
    • Rapid involuntary muscle movements



What defects arise from endocarditis in rheumatic fever?

  • Mitral valve is involved more commonly than the aortic valve
  • Small vegetations along the lines of closure that lead to regurgitation 


What defects arise from myocarditis in rheumatic fever?

  • Aschoff bodies 
    • Foci of chronic inflammation
    • Contain characteristic Anitschkow cells
      •  Reactice histiocytes with slender wavy nuclei
    • also contains giants cells, and fibrinoid materal
  • Most common cause of death from rheumatic fever


What defects arise from pericarditis?

  • Friction rub
  • Chest pain


What long term effects may arise from acute rheumatic fever?

Chronic rheumatic heart disease. Repeat exposure to GAS results in relapse of the acute phase which increases risk for chornic disease. 


What is chornic rheumatic heart disease?

Valve scarring that arises as a consequence of rheumatic fever


What is the most common consequence of chronic rheumatic heart disease?

  • Valve scarring with classfic fish mouth appearance
  • Almost always involves mitral valve
    • Thickening of chordae tendinae and cusps
  • Occasionally involves aortic valve
    • fusion of commissures


What is one potential significant complication from rheumatic heart disease?

Infectious endocarditis


What is endocarditis?

  • Inflammation of the endocardium lining the surface of the cardiac valves
  • Usually due to bacterial infection 


What valve is most commonly involved in endocarditis?

mitral valve


What is the most common overall cause of endocarditis?

Streptococcus viridians 


What is the pathophysiology in S. viridians endocarditis?

  • Low-virulence organism
  • Infects previously damaged valves
    • i.e. rheumatic heart disease
    • MVP
  • Results in vegetations that do not destroy the valve
    • Subacute endocarditis 
    • Damaged valves develop thrombotic vegetations
    • Transient bacteremia leads to trapping of bacteria in vegetations 


What is the most common cause of endocarditis in IV drug abusers?

Staphylococcus aureus


What is the pathophysiology of S. aureus endocarditis?

  • High virulence organism that infects normal valves
  • Most commonly affects tricuspid 
  • Results in large vegetations that destroy the valve
    • Acute endocarditis 


What organism is associated with endocarditis of prosthetic valves?

  • Staphlyococcus epidermis 


What organism is associated iwht endocarditis in patients with underlying colorectal carcinoma?

Streptococcus bovis 


What organisms involved in bacterial endocarditis have a negative blood culture?

HACEK organisms

  • Haemophilus 
  • Actinobacillus
  • Cardiobacterium
  • Eikenella
  • Kingella


What are the clinical features of bacterial endocarditis?


  • Fever
  • Roth's spots
    • round white spots on retina surrounded by hemorhage 
  • Osler's nodes
    • tender raised lesions on finger or toe pads
  • Murmur
  • Janeway lesions
    • small erythematous lesions on palm or sole
  • Anemia
  • Nail-bed hemorrhage
  • Emboli



What are the laboratory findings of bacterial endocarditis?

  • Positive blood cultures
  • Anemia of chronic dz
    • decreased Hb
    • decreased MCV
    • increased ferritin
    • decresaed TIBC
    • decreased serum iron
    • decreased % saturation
  • Transesophageal echocardiogram is useful for detecting lesions on valves


What is hte common cause of nonbacterial thrombotic endocarditis?

Sterile vegetations that arise in association with a hypercoaguable state or underlying adenocarcinoma.


What is libman-sacks endocarditis?

Endocarditis due to sterile vegetations that arise in association with SLE. Vegetations present on surface and underside of the mitral valve resulting in regurgitation. 


What are the complicatiosn from bacterial endocarditis?

  • chordae tendinae 
  • glomerulonephritis 
  • suppurative pericarditis
  • emboli