endocarditis

Question 1

endocarditis

Answer 1

• signs and symptoms of infection (fever, lethargy)
• embolic phenomena (splinter haemorrhages)
• abnormal heart valve
  (most commonly mitral & aortic)

Question 2

valve abnormalities - murmur

Answer 2

early diastolic murmur heard due to aortic regurgitation

Question 3

pathogenesis of endocarditis

Answer 3

1. turbulent flow through an abnormal valve (due to congenital or RHD)
2. turbulent flow damaged endothelial surface
3. damaged surface means collagen, fibrin and platelets adhere = form vegetations
4. transient bacteraemia (from gut, mouth, skin etc) seeds bacteria into sterile vegetations
5. infected vegetations enlarge, causing risk
   
   • vegetation breaks off -> emboli -> infarct
   • impaired valve function -> HF

Question 4

pathogens causing endocarditis and where they come from

Answer 4

mouth = viridian streptococci

skin/nose = staph aureus

gut/urinary tract = enterococcus faecalis

Question 5

why do neutrophils not kill this bacteria? And was does this mean?

Answer 5

• valves are vascular = no capillaries to deliver neutrophils
• flow across valve is to quick to allow neutrophils adhesion

therefore can’t be eradicated without antibiotics

Question 6

diagnosis

Answer 6

• continuous bacteraemia (positive blood cultures on 3 seperate occasions 20mins apart)

culture excised valve

echocardiogram

Question 7

treatment

Answer 7

IV antibiotics for 2-4 weeks

Question 8

RF vs endocarditis

Answer 8

RF

• S pyogenes only
• pharyngitis
• autoimmune damage to valves
• nodules on valves
• tx = oral penicillin 10 days

endocarditis

• viridian strep and others
• mouth commensal bacteria
• infection to valves
• vegetations on valves
• Tx IV penicillin 1 month