Infections of Cardiovascular Flashcards
(101 cards)
1
Q
what is primary bacteremia?
A
direct inoculation of the blood stream (nosocomial, IV drug use)
2
Q
what is secondary bacteremia?
A
microorganisms causing infection at another site (pneumonia) invade the blood stream and disseminate via the circulation to other body areas (hematogenous spread) - (ex. opportunistic)
3
Q
what is transient bacteremia?
A
self resolving in people with NO underlying illnesses, immune deficiency or turbulent cardiac blood flow
4
Q
what is bacteremia?
A
presence of bacteria in the bloodstream; may or not be clinically significant
5
Q
what is sepsis?
A
life threatening organ dysfunction due to dysregulated host response to infection (body response to an infection injures its own tissues and organs)
6
Q
what is septic shock?
A
subset of sepsis in which underlying circulatory and cellular/metabolic abnormalities are profound enough to substantially increase mortality
7
Q
what is the critical criteria for septic shock?
A
- sepsis
- hypotension requiring vasopressors to maintain mean arterial pressure (MAP) >65 mm Hg despite fluid restriction
- lactate > to 2 mmol/L
8
Q
what are the characteristics of sepsis?
A
- infection (suspected or confirmed)
- acute, life threatening organ dysfunction as defined by a sepsis related organ failure assessment (SOFA) tool
(SOFA)= measures respiratory, hepatic, CV, renal, CNS and platelet dysfunction
9
Q
what is the endocardium?
A
thin continuous lining inside the chambers of the heart, extends to cover the valves
10
Q
what is the myocardium?
A
muscle tissue of the heart (middle layer)
11
Q
what is the pericardium?
A
thin double-layered sac that encloses the heart
12
Q
what is rheumatic fever?
A
autoimmune reaction
complication of streptococcal pharyngitis (strep) infections
13
Q
what microbe causes rheumatic fever?
A
streptococcus pyogenase (group A streptococcus)
14
Q
what people most commonly get rheumatic fever?
A
most are socioeconomicly disadvantaged, low/middle incomes countries (indigenous children an young peoples)
15
Q
how long does rheumatic fever last for?
A
approx 3 months
16
Q
what is the patho of rheumatic fever?
A
form of molecular mimicry; microorganisms with episodes similar to host self- antigens triggers autoimmune mediated tissue damage
17
Q
who is erythema marginatum rarely observed in?
A
adults
18
Q
who is chorea rarely observed in?
A
adults, observed in children
19
Q
what is carditis?
A
- inflammation of heart valves (valvulitis), no infection
- acute valvulitis: valvular regurgitation, chronic valvulitis, valve stenosis
- typically effects left sided valves, with greater affinity for mitral valve
- HF symptoms develop with progressive heart valve damage
20
Q
what is polyarthritis?
A
large joints, lasts approx 2-4 weeks
21
Q
how can you prevent rheumatic fever?
A
prophylaxis with treatments antibiotics
22
Q
how can you prevent rheumatic fever with NO residual HD?
A
benzathine penicillin G, IM q/4 weeks until age 21 or 10 years after last ARF, lifetime prophylaxis may be needed
23
Q
how can you prevent rheumatic fever with residual HD?
A
benzathine penicillin G, q/4weeks until age 40 or 10 years after last ARF, lifetime prophylaxis may be needed
24
Q
what is residual HD referred to as?
A
persistent valvular disease - referred to as rheumatic valve
25
is there a treatment/cure for acute rheumatic fever?
no, management
26
what drugs can help acute rheumatic fever to relieve inflammation and bed rest?
anti inflammatory drugs
- pharmacologic therapies used for HF (if symptomatic)
27
what procedure may be required for residual HD?
valvuloplasty and valve replacement
(percutaneous mitral balloon commissurotomy for mitral valve stenosis is the Tx of choice in those with a suitable valve)
28
clients with rheumatic heart valve are at an increased risk for complications associated with what?
bacteremia
29
why do transient cases of bacteremia become problematic?
bc the microbe has a new place to adhere (due to roughening of endocardium), increasing risk of infective endocarditis
30
the increased risk of bacteremia with rheumatic heart valve is associated with what?
turbulent blood flow at site of the damaged valve an resulting damage to the endocardium
31
minor fibrin and platelet deposition can occur on the low pressure side of the damaged valve and can lead to?
non bacterial thrombotic endocarditis (NBTE)
32
what are splinter hemorrhages?
linear lesions in the long axis of the distal third of the nail
33
what are janeway lesions?
painless macular lesions, commonly on palmer surfaces of hands and feet (septic emboli)
34
what are oslers nodes?
small painful nodular lesions commonly on pads of fingers and toes, mainly seen in cases of subacute endocarditis
35
what are Roth spots?
pale - centered retinal hemorrhages; fibrin and platelet aggregation in white center
36
what is acute endocarditis associated with?
highly virulent bacteria (staphylococcus aureus)
37
how do symptoms manifest in acute endocarditis?
develop quickly (days), high fever (38.9-40), chills, tachycardia
38
what is acute endocarditis?
new or changing heart murmu, peripheral manifestations
39
what is subacute endocarditis?
new or changing heart murmu, peripheral manifestations
40
how do symptoms manifest in subacute endocarditis?
develop slowly (weeks to months); mild fever, malaise/fatigue, weakness, myalgia, cough, headache, back or chest pain and wt loss
41
what is subacute endocarditis associated with?
commensal (low virulence) microorganisms (viridian's group streptococci from oropharynx) an mostly seen in cases of pre existing valve damage
42
when should be prevention measures be used with endocarditis?
pt who are at high risk of IE who undergo procedures that are associated with transient bacteremia should receive antibiotic prophylaxis
43
how is endocarditis treated?
targeted parental antimicrobial therapy (long duration, eg. 4-6 weeks depending on susceptibility an nature of valve)
- some clients may switch to oral therapy if clinically stable (after 2 weeks)
44
50% of clients require what procedure in endocarditis?
valve surgery
45
is myocarditis more commonly associated with adults or paediatric cases?
Paediatric
46
how do symptoms develop in adults (myocarditis)?
progress slowly; progressive HF and dilated cardiomyopathy
47
how do symptoms develop in kids (myocarditis)?
acute symptoms in meds patients, cariogenic shock and acute HF, sudden death
48
what is myocarditis most commonly associated with?
a viral infection of the myocardium and infiltration of cardiac muscle by T lymphocytes
(enteroviruses (cocksackievirus B), adenovirus, HHV, influenza, SARS-Co-V-2, HIV)
49
what acts as a portal of entry in myocarditis?
CAR (cocksackie-adenoviral receptor)
50
how is CAR (cocksackie-adenoviral receptor) expressed?
expressed in myocytes-higher concentration in children (younger hearts) than adults (older hearts)
51
what are complications of myocarditis?
prolonged symptoms, which can lead to...
- worsening HF, death (or cardiac transplantation)
- dilated cardiomyopathy, heart attack and stroke
52
what is the treatment for myocarditis?
immunosuppressive therapy (steroids)
- similar to Tx of HF (ACE inhibitor, beta blocker)
53
why should NSAIDS be avoided in Tx of myocarditis?
increases risk of mortality from HF
- induce fluid retention (due to vasoconstriction of blood vessels in kidney an the resulting retention of Na+ and K+)
54
what are symptoms of myocarditis?
Hx of recent (within 1-2 weeks) flulike syndrome of fevers and malaise, pharyngitis, tonsillitis or upper RT infection
55
symptoms of mild HF:
fatigue, weakness, SOB, edema, palpitations, arrhythmia
56
what are causes of pericarditis?
viruses are the most causative pathogen, appears 2-3 weeks post "flu like" illness
- non infectious causes should be considered (meds, vaccines)
57
pericarditis is associated with what other inflammatory disease?
may co exist with myocarditis
58
what is the pharmacologic therapy for pericarditis?
analgesics and anti inflammatory drugs (NSAIDS or steroids); assess for concomitant myocarditis
- antibiotics for bacterial causes (more severe)
59
what surgical/procedure can be done for Tx of pericarditis?
- pericardial tamponade
- pericardiocentesis (drainage of pericardial fluid)
- constrictive pericarditis pericariectomy (removal of pericardium)
60
diagnostic findings for pericarditis?
- echocardium - appearance of fluid surrounding heart
- abnormal ECG
- abnormal heart sounds "pericardial rub"
61
what are symptoms of pericarditis?
sharp, stabbing chest pain caused by rubbing of two layers of the pericardium
62
when does pain worsen in pericarditis?
when lying down, deep breaths, swallowing, coughing
63
when does pain improve with pericarditis?
sitting up right or forward
64
what is the most common vector bone infectious disease in the temp northern hemisphere, effecting thousands of people annually in North America?
Lyme disease
65
what type of bacteria is Borrelia burgdorferi?
(Gram neg) spirochete - shaped bacteria with periplasmic flagella, motile
66
how is Borrelia burgdorferi (Lyme disease) transmitted?
transmitted to humans by infected deer ticks (Ixodes scapulars and Ixodes pacificus)
67
what is the portal of entry in Lyme disease?
tick bite; spirochetes spread locally in the dermis at a rate of 4m/sec
68
what induces inflammation at the site of the tick bite?
tick saliva induces local inflammation at site of bite; ring of inflammation follows the migrating bacteria
69
with a tick bite, where does the bacteria travel?
bacteria moves from the sit of infection into blood and lymph, causing systemic symptoms
70
a backlegged tick attaches to host and sucks blood for how long?
several days
71
the longer the tick is attached, the greater the risk of acquiring _______.
Lyme disease
72
why do you not acquire Lyme disease right away when you get a tick bite?
bc it takes time for borrelia to move from the tick to the host through the saliva
73
how do ticks attach to their host?
ticks cannot jump/fly; they wait for a host on grasses and shrubs
- hold upper pair of legs outstretched, waiting to clime onto a passing host, then bites
74
what are the 3 main techniques to prevent tick bites?
1. coverup (light coloured clothing, and fully covered)
2. use insect repellent w/ DEET or icaridin (use on clothes an skin)
3. do a tick check (put clothes in dryer; high heat kills ticks, do this before washing)
75
where should you check for ticks?
- back of body
- have showers to wash off ticks
- after being outdoors, check
- check pets for ticks
76
what to not do when removing a tick?
- do not crush, squeeze or damage the tick; this could facilitate infection
- do not use a lit match or cigarette, nail polish or remover, petroleum jelly, liquid soap or kerosene to remove tick
- if the tick is alive, put it in a secure container and contact local health unit
77
how to remove a tick:
use tweezers, pull tick upward with steady and even pressure, dont twist or jerk the tick, after removing tick, thoroughly clean the bite area and your hands with rubbing alcohol or soap and water
78
what are the three stages of the complex life cycle (deer ticks)?
larva, nymph, adult
79
how long do deer ticks last for?
2 years
80
what happens in the larvae stage?
larvae become infected with first blood meal; bacteria replicate in their digestive system during winter
- the following spring, ticks most into nymphs and feed a second time, infecting new hosts with borrelia
81
what happens in the nymph stage?
nymphs drop of host and develop into adults and feed final time (infecting their host), then mate, lay eggs, then die
82
how big are nymphs?
size of a poppy seed
83
infected ticks must remain attached to host for how many hours to transmit sufficient spirochetes to establish borrelia function?
36-48
84
adults stage:
adults are larger than nymphs so humans often see and remove adults before they can transmit the bacteria and nymphs most often responsible for human infection
85
how big is an adult tick?
size of a sesame seed
86
what is the most common sign of localized Lyme disease?
expanding skin rash usually at site of tick bite that appears within 3-30 days (avg 7 days)
87
does every person with Lyme disease develop a rash?
no
88
early signs and symptoms of localized Lyme disease:
rash, fever chills, headache, stiff neck, fatigue, decreased appetite, muscle/joint aches, swollen lymph nodes
89
what happens if the infection from a tick is left untreated?
can spread to joints, heart and NS (dissemated infection)
90
what is erythema migrans?
rash, slow growing over several days and can reach up to 30 cm across, lasting several weeks (can be circular or oval shaped "bulls eye"), may feel warm but not itchy or painful
91
what can help prevent dissemated infection in Lyme disease?
early Dx and proper antibiotic Tx of Lyme disease
92
what is the Tx for localized Lyme disease?
most people Tx with antibiotics in early localized phase of Lyme disease recover rapidly and completely
93
why is Dx challenging in Lyme disease?
symptoms vary from person to person
94
what is Dx based on for Lyme disease?
symptoms, travel Hx, exposure to backlegged ticks
- blood test may be required
95
how can the infection of Lyme disease dissemate?
in the absence of prompt identification and Tx, the infection can dissemate, which can lead to MSK, neurological, or cardiac manifestations within 1-4 months after initial infection
96
what are the symptoms of dissemated Lyme disease?
- lyme carditis, palpitations, arrythmias, peri/myocarditis
- conjunctivitis an/or damage to deep tissue in eyes (meningitis/encephalitis)
- intermittent pain, weakness or numbness in arms or legs, facial palsy (shooting pain, numbness or tingling in hands and feet)
- arthritis an pain, redness an swelling in 1 or more large joints (often the knee)
- skin rashes distal to the portal of entry an original rash
97
how to Dx dissemated Lyme disease?
signs an symptoms, serologic testing for the presence of antibodies (IgG testing should be done)
- borrelia burgdorteri antigens differ from religion to religion, travel Hx is important
98
due to antibody persistence single positive serologic test results cannot distinguish between?
active and past infection
99
what is Late Persistent Lyme disease Syndrome (PTLDS)?
borrelia burgdorteri may trigger an autoimmune response causing symptoms that persist well after the infection is eradicated, autoimmune responses occur following other bacterial infections
100
what is PTLDS thought to be associated with?
tissue damage that occurred before the infection was eliminated
101
is PTLDS a chronic infection?
no
