Intro to CV Infectious Disease

Question 1

What are the 7 CV infectious diseases we learn about?

Answer 1

endocarditis
myocarditis
pericarditis
rheumatic heart diseae
catheter-related infections
machine infections (valves, pacemakers, defibrillators,)
Rocky Mountain Spotted Fever

Question 2

Is infectious endocarditis a bacterial or viral disease?

Answer 2

bacterial

Question 3

What is a physical predisposing factor to infectious endocarditis? WHy?

Answer 3

an underlying heart defect - congenital or prior/chronic damage to endocardium

injury to the epithelium causes aberrant blood flow and allows for infection directly by organisms (and for clots)

Question 4

What do the bacteria grow to form on valves and heart tissue in infectious endocarditis?

Answer 4

vegetations - collections of bacteria, platelets, fibrin and inflammatory cells

Question 5

What is a behavioral predisposing factor to endocarditis?

Answer 5

IV drug use (typically right-sided infecitons)

Question 6

What are the common portals of entry for the pathogens that cause endocarditis?

Answer 6

oral cavity, skin and upper respiratory tract into the bloodsream

Question 7

What culture will typically be positive in infectious endocarditis?

Answer 7

blood cultures will be positive for bacteria

Question 8

What symptoms are associated with subacute onset of infectious endocarditis?

Answer 8

low grade fever, night sweats, chills, fatigue, malaise, weakness, anorexia and low back pain

Question 9

What physical exam findings will be noted in subacute infectious endocarditis?

Answer 9

cardiac murmur
conjuncitval petechiae
splinter hemorhage in the nails
Osler Nodes
Roth's spots
Janeway lesions

Question 10

What lab findings will also be positive in endocarditis besides the blood cultures?

Answer 10

anemia
elevated sed rate
elevated CRP
presence of rheumatoid factor
circulating immune complexes

Question 11

What are the most likely causative microorganisms for infectious endocarditis?

Answer 11

streptococcus spp. (viridans) - most common community acquired
Staphylococcus aureus - most common Nosocomial and in IV drug users)
Enterococci
Coagulase-negative staphylococci

Some can be culture-negative
IV drug users can also have polymicrobial infections or gram-negative bacillia

Question 12

Is myocarditis typically a viral or bacterial infections?

Answer 12

viral

Question 13

What are the common symptoms of myocarditis?

Answer 13

flu-like illness with chest pain

some patients will have an arrhythmia and feel like they are having a heart attack

Question 14

What are the two more common microorganisms for myocarditis? Which one in chidlren?

Answer 14

Coxsackie B virus

Adenovirus - children

Question 15

Is pericarditis typically a bacterial or viral illness?

Answer 15

viral

but bacterial can also occur by hematogenous spread, trauma or cardiac surgery

Question 16

What time of the year is viral pericarditis more common? Coinciding with what?

Answer 16

spring and summer; coinciding with higher incidence of enterovirus infections

Question 17

In pericarditis, when does the chest pain because exacerbated?

Answer 17

When they swallow or when they are supine

Question 18

What will all patients have on exam in pericarditis?

Answer 18

tachycardia
characteristic three-component friction rub

EKG changes frequent

Question 19

Lab tests after what procedue can help establish etiology in pericarditis?

Answer 19

pericardiocentesis

Question 20

What are the 4 most common viruses to cause pericarditis?

Answer 20

coxsackie A and B
Echoviruses
Influenza virus

Question 21

What are the 4 most common bacteria to cause pericarditis?

Answer 21

stpahylococcus aureus
Strep pneumoniae
Haemophilus influenza
Neisseria meningitidis

Question 22

Rheumatic heart disease follows what bacterial infection?

Answer 22

strep pyogenes pharyngitis

Question 23

In Rheumatic heart disease, the damage to the heart muscle and valves is attributed to what?

Answer 23

autoantibodies

Question 24

What is the definitive clinical indicator for rheumatic heart disease?

Answer 24

mitral stenosis following pharyngitis with rash

Question 25

What is the main source of the bacteria in intravascular-catheter-related infections?

Answer 25

the skin

Question 26

What viral factor allows bacterial to colonize in catheter related infections?

Answer 26

biofilms

Question 27

What's the most common causative agent for catheter-related infections?

Answer 27

staph aureus

Question 28

which valve is most often affected by endocarditis?

Answer 28

the mitral valve (tricuspid for IV drug users)

Question 29

How do acute and subacute endocarditis differ?

Answer 29

acute - extremely febrile with rapid progression to death. seeds infection in distal sites and rapidly damages the heart subacute - more indolent course, gradually progressive, rarely seeds ifnection, damages heart slowly

Question 30

What are ROth spots

Answer 30

white-centered retinal hemorrhages seen on fundoscopic exam in endocarditis

Question 31

What does strep viridans refer to?

Answer 31

strep that undergoes alpha hemolysis - green on blood agar

Question 32

what's the most common species of strep viridans?

Answer 32

strep mutans

Question 33

What are the Duke Criteria for endocarditis?

Answer 33

2 major criteria or 1 major criteria/3 minor or 5 minor met: major: 1. positive blood cultures (2 separate in time) 2. evidence of endocardial involvements minor; 1. predisposition (heart condition or drugs) 2. fever above 38 C or 100.3 F 3. Vascular phenomena (arterial emboli) 4. Immunological phenomena Roth's spots 5. Microbial evidence - postivie blood culture but not meeting major criteria

Question 34

What are janeway lesions?

Answer 34

non-tender small haemorrhagic lesions on palms and soles

Question 35

What are osler's nodes?

Answer 35

painful, red, raised lesions on hands and feet (immune complex deposition)

Question 36

What is the number one cause of endocarditis?

Answer 36

staph aureus from the skin

Question 37

How does strep aureus evade the host defenses?

Answer 37

protein A to bind Fc of IgG coagulase (forms fibrin coast around organism) hemolysins and leukocidins to destroy blood cells

Question 38

How does staph auerus penetrate deep tissues?

Answer 38

hyaluronidase to break down CT staphylokinase to lyse formed clots lipase to break down fat

Question 39

Which one can infect HEALTHy valves: staph aureus or step viridans?

Answer 39

staph

Question 40

What can the viridans species produce to help glycocalyx formation go assist colonization?

Answer 40

dextran

Question 41

what's the most common strep viridans species?

Answer 41

strep mutans

Question 42

How can a strep pyogenes infection lead to damaged heart valves?

Answer 42

It has an M protein (resists phagocytosis) which our body will mount an immune response to. the antibodies then cross react with heart valve tissue

Question 43

What type of hypersensitivity reaction is the strep pyogenes damage to the heart?

Answer 43

type 2 (antibody mediated)

Question 44

What's the general treatment for endocarditis?

Answer 44

high dose, long-term treatment with an orgnism-specific bactericidal antibiotic

Question 45

What is myocarditis an infection of?

Answer 45

the myocardium, or middle layer of the heart wall

Question 46

Why do Coxsackie B virus and Adenovirus cause myocarditis, but not coxsackie A?

Answer 46

Because it can't bind the receptor present on the myocardial cells, the CAR receptor

Question 47

When does rhematic fever/ heart disease typically occur? in what age group?

Answer 47

2-4 weeks after strep infection 5-15 year olds most common

Question 48

What are the symptoms of rheumatic fever?

Answer 48

pain and swelling of alrge joints, fever, weakness, muscle aches, SOB, CP, N/V, cough, circular rash, lumps under skin

Question 49

Prosthetic valve infections during the initial year following surgery are usually from what? How about later than a year after?

Answer 49

staphylococcus epidermidis after - streptococcus viridans

Question 50

Infections within the first two weeks post pacemaker/defibrillator implant are usually from what? How about after 2 weeks?

Answer 50

staphylococcus aureus then coagulase negative staph species like Staph epidermidis

Question 51

A high percentage of patients with an infected valve, pacemaker or defibillator will also have what type of infection?

Answer 51

endocarditis

Question 52

What's the most common rickettsial infection in the US?

Answer 52

rocky mountain spotted fever

Question 53

How does rocky mountain spotted fever cause hemorrhages?

Answer 53

The rickettsia spread through the body in the blood and are engulfed by the endothelial cells, were they multiply. This multiplication causes leakge of RBCs from the vessels, causing the petechial rash and hemorrhages.

Question 54

What are the symptoms or rocky mountain spotted fever?

Answer 54

fever, HA, abd pain, vomiting, muscle pain. Rash may develop after the first few days or never develop

Question 55

What is the first line of treatment ro rocky mountain spotted fever?

Answer 55

Doxycycline

Question 56

What tick spreads rickettsia?

Answer 56

the dermacentor wood tick or the dog tick