1- Endocarditis

Question 1

What causes the symptoms of endocarditis?

Answer 1

Immune response
Immune complexes
Emboli

Question 2

What causes endocarditis in non-IV drug users?

Answer 2

Staph a (most common)
Strep viridans
Enterococcus species

Question 3

What is the blood flow through the heart chambers and what are the valves doing?

Answer 3

You better know this by now!!!

Question 4

Know the virulence factors of the causative organisms.

Answer 4

Look in the microbiology section

Question 5

How does bacterial endocarditis cause heart murmurs?

Answer 5

Valves cannot close/open properly with the vegetation on them

Question 6

Differences in visualizing valvular vegetation

Answer 6

Transthoracic echo: easier…not as good of a look

Transesopheal echo: obtrusive…better look

Question 7

How to differentiate among the species of viridans-type streptococci?

Answer 7

PCR of rRNA
Blood agar (alpha, beta, gamma)
API (a bunch of wells)

Question 8

What causes the relationship of endocarditis and stroke?

Answer 8

There are septic emboli that break off of the vegetation and enter the blood stream

Question 9

What is the mechanism of tissue Plasminogen Activator (tPA)? What is the risk of tPA?

Answer 9

“Selectively” activates fibrin-bound plasminogen–>breaks apart fibrin
Although it would break apart the embolus, by doing so it would release the bacteria into the brain

Question 10

What is the mechanism of streptokinase? What is the risk of streptokinase?

Answer 10

Binds to plasminogen…opens up the active site to make it plasmin
The streptococcal antibodies will likely attack the drug

Question 11

What is the mechanism of urokinase? What is the risk of urokinase?

Answer 11

Activates plasminogen directly via enzyme activation
Is not fibrin-bound selective
Could have same issues as tPA

Question 12

What causes drug-resistance to pharmacology treatments for bacterial infections of the heart?

Answer 12

The inner bacteria are not replicating and will not be killed by drugs that rely on active multiplication

Question 13

What physical exam findings are associated with emboli?

Answer 13

Stroke
Splinter hemorrhages
Janeway lesions (painless)

Question 14

What causes rheumatic fever? Why are people with a history of ARF at risk for endocarditis?

Answer 14

Strep pyogens causes ARF

During antibody formation mimicry occurs that makes antibodies to meromyosin

Question 15

What is the evidence of endocarditis having a genetic component?

Answer 15

There have been twin studies done comparing rates b/w monozygotic and dizygotic twins