8.5 Endocarditis

Question 1

Most common pathogen in endocarditis and features

Answer 1

Strep. viridans
From dental procedures
Can only infect previously damaged valves that have fibrin and platelet healed part that traps the bacteria in the blood
Low virulence means it doesn’t destroy valve and only causes small vegetations

Question 2

Most common pathogen in IV drug users and features

Answer 2

Staph. aureus
Commonly infects tricuspid valve
High virulence means infects healthy valves, destroys valves, large vegetations

Question 3

Pathogen in prosthetic valves

Answer 3

Staph. epidermidis

Question 4

What should you think about if endocarditis is found to be caused by Strep. bovis?

Answer 4

Colorectal carcinoma

Question 5

What pathogens are considered if endocarditis is present but cultures are negative?

Answer 5

HACEK organisms
Haemophilus
Actinbacillus
Cardiobacterium
Eikenella
Kingella

Question 6

Clinical features of endocarditis

Answer 6

Fever
Murmur
Septic emboli leading to: Janeway lesions (painless lesions on palms and soles), Osler nodes (painful lesions in fingers and toes), splinter hemorrhages, Roth spots
Anemia of chronic disease

Question 7

Lab and radiology findings of endocarditis

Answer 7

Positive blood cultures in most cases
Anemia of chronic disease (high ferritin, low TIBC, low sat, low blood iron, low MCV)
TEE shows valve lesions

Question 8

Two types on sterile endocarditis leading to vegetations

Answer 8

Nonbacterial thrombotic endocarditis: caused by hypercoagulable state or underlying adenocarcinoma

Libman-Sacks endocarditis: associated with SLE and vegetations on both sides of the valve