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INFECTIVE ENDOCARDITIS
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INFECTIVE ENDOCARDITIS

Definition : proliferation of microorganisms on the
endocardial surface of heart
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Bacteria , chlamydiae , rickettsiae , mycoplasma , fungi and
virus
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Vegetation : mass of plt. , fibrin , microcolonies of
microorganism , scant inflammatory cell
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Moss common : heart valves
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Infective endarteritis
CLASSIFICATION

Acute : fulminant, high fever, rapidly damages cardiac
structures, hematogenously seeds extracardiac sites,
death < 6 wk
: Staphylococcus aureus ,
Streptococcus pyogenes ,
Streptococcus pneumoniae , or
Neisseria gonorrhoeae
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Subacute : indolent course, rarely causes metastatic
infection, death in 6 wk-3mo
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Chronic : death > 3 mo
INCIDENCE
1.5-6.5 / 100,000 /year
 Half : injection drug use
 Notably increased among elderly
 Prosthetic valve : Cumulative rate 1.5-3% at 1 yr
3-6% at 5 yrs
: greatest 6 mo.
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ETIOLOGY
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Many species of bacteria and fungi
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Portals of entry
- Oral, skin, URI : S. viridans, Staphylococci,
HACEK
- GI : S. bovis (ass. Polyps & colonic tumors)
: G –ve (Enterobacteriacae)
- GU : Enterococci
- Nosocomial : intravascular catheters : S.aureus
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Prosthetic valve
: 2mo , NI
: Intraoperative contamination
: Bacteremic postoperative
: S.coag.-ve, S. aureus, G-ve rod, diphtheroids,
fungi
: >12mo. = Community-acquired native valve
:>85% S.coag-ve : MRSA
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Transvenous pacemaker and/or implanted
defibrillator
: NI , within weeks, S. aureus, S.coag -ve
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Injection drug users
- TV
- S.aureus strains : MRSA
- Lt side : varied etiology & abnormal valve
: P.aeruginosa, Candida spp.,
: Bacillus, Lactobacillus,
: Corynebacterium
-Polymicrobial

H/C negative
- 5-15%
- 1/3-1/2 : prior ATB
- fastidious : Pyridoxal-requiring S.,
G-ve coccobacillary HACEK
Bartonella henselae/quintana
Tropheryma whipplei
PATHOGENESIS
Mucous membrane or other
colonized tissue
Valvular endothelium
trauma
turbulence
metabolic
Platelet-fibrin deposition
Trauma
Nonbacterial thrombotic
endocarditis (NBTE)
Bacteremia
Complement Ab
Adherence
Colonization
bacterial division
fibrin depositon
platelet aggregation
extracellular proteases
neutrophils protection
mature vegetation
PATHOLOGIC CHANGES

Heart
- classic vegetation : line of closure
: atrial surface of atrioventricular valve
: ventricular surface of semilunar valve
- singer or multiple
- few mm. to several cm. in size
- vary in color, consistency, gross appearance
- microscopic : fibrin, platelet aggregates, bacterial mass,
rare PMN&RBC
- destruction of underlying valve , fibrosis after healing
- acute : larger, softer, friable, may
suppuration, more necrosis, less healing than
subacute
- large : valvular stenosis
- may perforation
- valve ring abscesses with fistular formation
- aneurysms
-CHF, myocarditis, MI, pericarditis

Kidney
3 processes : infarction 56%
: glomerulonephritis - focal 48-88%
- diffuse 17-80%
: abscesses – uncommon
- normal size, slightly swollen, petechiae
- all case : abnormal renal architecture

Mycotic aneurysms
- 10-15%
- acute IE
- S. viridans
- mechanism : direct bacterial invasion
: septic embolic occlusion
: immune complex deposition
- bifurcation points, common-cerebral vv
(MCA)
- clinically silent until rupture
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CNS
-
-
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Cerebral emboli
MCA and its branches
Cerebral infarction, arteritis, abscesses, mycotic
aneurysm, ICH, SAH, encephalomalacia,
cerebritis, meningitis
Hemorrhagic transformation of ischemic infarctfatal
Pneumococcal : purulent meningitis
S. aureus : multiple microabscesses
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Spleen
- splenic infarction 44% : silent
- splenic abscess : uncommon
Lung
- Rt side IE : PE +- infarct, pneumia, effusion, empyema
Skin
- petechiae 20-40%
- Osler nodes : immune complex in dermal vessels,
arteriolar intimal proliferation
- Janeway lesions : septic emboli
: consist of bacteria, neutrophile
: necrosis, subcutaneous hemorrhage
Eye
- Roth spots : lymphocytes surrounded by edema and
hemorrhage in nerve fiber of retina
CLINICAL MANIFESTATION
S&S : protean, and any organ system may be
involved
 4 processes
1.infectious process on the valve + complication
2.septic embolization
3.constant bacteremia
4.circulating immune complex
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Fever : remittent, rarely exceeds 40 c
Half : afebile within 3 d. of the initiation of ATB ,
75% after 1 wk , 90% after 2 wk
Prolonged fever : specific etiologic agents
- S. aureus, G-ve bacilli, fungi, H/C –ve IE
- microvascular phenomena
- embolizaton of major vessels
- intracardiac – peripheral complication
- tissue infarction
- PE
- drug reaction
- NI
Nonspecific symptom
- anorexia, N/V, wt.loss,
malaise,fatigue,chill, weakness, night
sweats
 Heart murmur
->85%
-may absent : Rt sided or mural infection
-classic but uncommon 5-10%
: changing murmur and development of a
new regurgitant murmur


Heart
-CHF
- Pericarditis is rare : myocardial abscess
- valvular stenosis/obstruction=Sx
- myocarditis
- MI

Classic peripheral manifestation
 Clubbing
finger 10-20%
 Splinter hemorrhages : proximal nail
Petchiae 20-40% : local vasculitis or emboli
: conjunctivae
: buccal mucosa, palate
: extrenities
Osler nodes 10-15%
: small, painful, nodular 2-15 mm, multiple
Janeway lesions : embolic
:Hemorrhagic, macular, painless plaques
Roth spots 5% near optic disk

Splenomegaly 25-60%
-splenic septic emboli : may abscent S&S

Musculoskeletal 44%
- proximal oligo/mono arthalgia
- LBP
-myalgia

Major embolic episodes
- splenic a. emboi : LUQ pain or Lt pleural effusion
- renal infarction : hematuria
-retinal a. emboli : sudden loss VA
-PE : Rt sided – narcotic addicts
-coronary a. emboli (AV) : myocarditis, arrhythmias,MI
-major vv. Emboli : femoral, brachial, popliteal, radial a.
: fungus
Neuro. 20-40%
- embolic : Staphylococcal
- mycotic aneurysms
- seizure, severe headache, visual loss,
CN palsy, toxic encephalopathy, psychosis
 Renal
- renal failure : uremia
- AGN

IE IN DRUG ADDICTS
Acute infection
 2/3 no underlying heart
 Most : TV alone or combine 52.2% (Rt side)
: AV 18.5%
: MV 10.8%
: AV+MV 12.5%
 TV : pleuritic chest pain, blood born pneumonia
: sign of tricuspid insufficiency
 Men 4-6 : 1 women
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ETIOLOGY IN NARCOTIC ADDICTS
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S. aureus 38% less severe than nonaddicts
P. aeruginosa 14.2%
Candida spp. 13.8%
Enterococci 8.2%
S. viridans 6%
S. epidermidis 1.7%
G-ve aerobic baciili 1.7-15%
Other bacteria 2.2%
Mixed infectious 1.3%
Culture negative 12.9%
ETIOLOGIC AGENTS

Streptococci
-most common : community , hospital
-common organism :S. viridans
- subacute
- multiple non specific symptom
->80% : underlying heart dz.
-cure rate >90% (nonenterococcus)
-GI: S.bovis, enterococci

Staphylococci
-20-30% of IE
-S. aureus coag+ve 80-90%
-acute IE
-normal heart valve 1/3
-fulminant :MV, AV
-40% death : myocardial abscess, purulent
pericarditis, valve ring abscess
-narcotic addicts : S. aureus – less severe
-S.epidermidis : prosthetic valve IE
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Enterococcus
-GI tract , ant. Urethra
-Lancefield group D
-5-18%
-subacute
-older men 59 yr : after GU manipulation
-younger women 37 yr : after obstetric
procedures
-40% no underlying heart : 95% develop
murmur
-high mortality

Gram negative bacilli
-10% of IE
-2/3 coexisted/followed serious G+ve infection
-most case : fastidious
-common :Enterobacteriaceae , Salmonela spp.
-increase risk :narcotic addicts
:prosthetic valve recipients
:cirrhosis
-40-50 yr., duration 6 wk, Lt side, poor prognosis
-persistent bacteremia vs g-ve septicemia
-High levels ATB activity
-2/3 normal heart valve AV & MV
-large vegatations & near total occlusion
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Pseudomonas
-abused intravenous drugs
-male:female = 2.5:1
-mean age 30
-major embolic phenomena & complications
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Unusual G-ve
-N. gonorrhoeae
-HACEK group :Haemophilus spp.
:Actinobacillus
:Cardiobacterium
:Eikenella corrodens
:Kingella
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G+ve bacilli
-Corynebacterium
-Listeria monocytogenes
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Anaerobic bacteria
HACEK
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-Fastidious
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Clinical syndrome
- subacute IE, large friable, freq.emboli, CHF,
need for valve replace
-2-3 wk : primary isolation
-subculturing : all culture-negative

Haemophilus spp.
-H. paraphrophilus, H. parainfluenzae, H. aphrophilus,
H. seguis, H. aegyptius
-0.8-1.3%
-subacute, vulvulae dz.
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Actinobacillus actinomycetemcomitans
-rare, subacute, mortality 34%
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Cardiobacterium hominis
- resembles Haemophilus

Eikenella corrodens
-IVDU
-usual habitant of oropharynx
-indolent

Kingella endocarditis
-50% : complication eg. stroke
FUNGI
3 pt group
-narcotic addicts
-reconstructive cardiovascular suegery
-prolonged intravenous ATB
 Underlying heart : 2/3 major systemic emboli
 Addicts : C. parapsilosis
: C. tropicalis
 Non addicts : C. albicans
: Aspergillus spp.

Acute
-B-hemolytic streptococci
-S. aureus (occasional:subacute)
-Pneumococci
 Subacute
-S. viridans
-Enterococci (may acute)
-S. coag –ve (may acute)
-HACEK group
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LAB
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Echocardiography
- identified vegetations
: confirm IE
: intracardiac complication
: size
: cardiac function
- sensitivity & specificity : uncertain
: TTE sens. 65% - Rt side, not seen <2mm
: TEE sens. >90% - prosthetic, intracardiac
complication
- vegetation > 1 cm : stroke
DIAGNOSIS
Clinical definite diagnosis
-2 major
-1 major + 3 minor
-5 minor
 Possible
-1 major + 1 minor
-3 minor
 Reject
-resolve/not recur <=4 d.ATB
-no histologic of endocarditis

TREATMENT
INDICATION

Empirically immediately ATB : take H/C 3 spp.
- acute IE
- deterioration hemodynamics
- may require urgent surgery
 Acute + IVDU : Vancomycin + Gentemicin
Subacute
 Prosthertic

: Ceftriazone + Gentamicin
:+Vancomicin
IE PROPHYLAXIS
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Single dose before procedure

Dental procedure
-S. viridans

Respiratory tract procedure
-S. viridans
-S. aureus

Skin & musculoskeletal
-Staphylococci
-B-hemolytic streptococci
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GI & GU procedure : not prophylaxis
-Enterococci
SUMMARY
1. Bacteremia from daily activity > procedure
 2. prevent : small number of case
 3. limit in table 3
 4. dental, RS, skin, musculoskelatal procedure
in underlying cardiac condition
 5. not recommen in GI & GU
