Infective endocarditis
Post on 27-May-2015
545 Views
Preview:
DESCRIPTION
Transcript
ww
w.m
edicin
em
cq.co
m
1
INFECTION OF THE ENDOCARDIUM
LINING LAYER OF THE HEART
Infective endocarditis
2
ww
w.m
edicin
em
cq.co
m
VALVE LEAFLETSMost commonly affectedMay also affect
ChordaeChamber wallsParaprosthetic tissue
3
PATHOGENESIS
First changeAlteration of the valve surface
Produced by various local and systemic stresses, including blood turbulence
www. medicinemcq.com
4
ww
w.m
edicin
em
cq.co
mNONBACTERIAL THROMBOTIC ENDOCARDITIS
Deposition of platelets and fibrinSterile vegetation
5
ww
w.m
edicin
em
cq.co
mPLATELET-FIBRIN DEPOSITIONOccurs spontaneously
Abnormal valvesCardiac endothelial injuryCardiac inflammation
These deposits are called NBTE
www.medicinemcq.com 6
www.medicinemcq.com 7
www.medicinemcq.com 8
9
BACTEREMIA Microorganisms adhere during bacteremia to initiate IE
www.medicinemcq.com
10
ww
w.m
edicin
em
cq.co
m
BACTEREMIAConverts nonbacterial thrombotic endocarditis to IE
11
ww
w.m
edicin
em
cq.co
m
BACTERIA
Certain strains adhere better
12
ww
w.m
edicin
em
cq.co
m
VEGETATION Consists of
FibrinPlatelet aggregatesBacterial masses
Neutrophils and red blood cells are rare
www.medicinemcq.com 13
14
SITE OF VEGETATIONS
Site of infectionUsually located along the line of closure of a valve leaflet
www.medicinemcq.com
15
ww
w.m
edicin
em
cq.co
m
WHERE DO VEGETATIONS DEVELOP?
Atrial surfaceAtrioventricular valves
Ventricular surfaceSemilunar valves
16
ww
w.m
edicin
em
cq.co
m
LARGE VEGETATIONS
Acute IEFungal endocarditis
17
LARGE VEGETATIONS
High incidence of systemic emboli
www.medicinemcq.com
18
ww
w.m
edicin
em
cq.co
m
WHEN DO LARGE EMBOLI CAUSE MAJOR VESSEL OCCLUSION?
Fungal endocarditisMarantic endocarditis
Intracardiac myxoma
19
ww
w.m
edicin
em
cq.co
m
NORMAL ENDOTHELIUM
Resistant to infectionBacteremia frequent
Endocarditis rare
20
ww
w.m
edicin
em
cq.co
mTWO FACTORS IMPORTANT IN THE FORMATION OF NBTE
Endothelial injury
Hypercoagulable state
21
HYPERCOAGULABILITY Valvular heart disease Intracardiac catheters SLE Malignancy Increasing age DIC Uremia
www.medicinemcq.com
22
HIGHEST RISK OF BACTEREMIA
Gingival trauma
23
ww
w.m
edicin
em
cq.co
m
RISK OF BACTEREMIA
Less with surgical procedures involving GU and GI tracts
24
ww
w.m
edicin
em
cq.co
m
ESSENTIAL FOR IEHigh velocity jet streamBlood passing through a narrow orifice with a high-pressure gradient
25
ww
w.m
edicin
em
cq.co
m
HIGH VELOCITY JET
Mitral regurgitationAortic stenosisVSD
26
ww
w.m
edicin
em
cq.co
m
HIGH VELOCITY JET
Damage to surface epithelium
Formation of a sterile thrombus
Nonbacterial thrombotic endocarditis
27
ww
w.m
edicin
em
cq.co
m
MITRAL STENOSIS AND ASD
No high-pressure jet
IE is very rare
www.medicinemcq.com
28
ww
w.m
edicin
em
cq.co
mMOST COMMON UNDERLYING LESION IN INDIA
Rheumatic heart disease
MV > 85%
29
ww
w.m
edicin
em
cq.co
mOTHER PREDISPOSING CONDITIONS
1. PDA2. VSD3. COA4. TOF5. Bicuspid AV 6. Prosthetic valves
30
ww
w.m
edicin
em
cq.co
m
ELDERLY Congenital bicuspid aortic valve
www.medicinemcq.com
31
ww
w.m
edicin
em
cq.co
m
MARANTIC ENDOCARDITIS
1. Malignancy 2. SLE3. Antiphospholipid
antibody syndrome
32
ww
w.m
edicin
em
cq.co
m
DIAGNOSIS OF APSClotting
Arterial or venousRepeated fetal lossesTwo positive tests for aPL > 6 weeks apart
33
ww
w.m
edicin
em
cq.co
m
HIV INFECTIONHigh incidence of antiphospholipid antibodies
34
ww
w.m
edicin
em
cq.co
m
HIVNot a risk factor for IEUnless associated with IV drug abuse
HIV-infected IV drug abusersIE is frequent
35
ww
w.m
edicin
em
cq.co
m> 90% OF THE ORGANISMS IN VEGETATIONS
Metabolically inactiveNot growing
Resistant to killing by antibiotics
36
ww
w.m
edicin
em
cq.co
m
WHICH BACTERIA COMMONLY CAUSE IE?
1. Streptococci2. Staphylococci3. Enterococci4. GNB
37
ww
w.m
edicin
em
cq.co
m
S. AUREUSCan adhere directly to intact endothelium or exposed subendothelial tissue
www.medicinemcq.com
38
ww
w.m
edicin
em
cq.co
m
LESS VIRULENT MICROORGANISMS
Adhere to thrombi
Proliferate to form dense colonies
39
ww
w.m
edicin
em
cq.co
m
ACUTE IE
Duration < 6 weeksS.aureus
40
ww
w.m
edicin
em
cq.co
m
ACUTE AR OR MRVirulent organisms
(e.g., staphylococcus aureus) attack normal valves
Rapid destruction of the valve
41
ww
w.m
edicin
em
cq.co
m
METASTATIC INFECTIONS
Hematogenous spread to other organs
www.medicinemcq.com
42
ww
w.m
edicin
em
cq.co
m
WHEN TO SUSPECT ACUTE IE
High fever Marked toxicityValvular destruction
Metastatic infection
43
ww
w.m
edicin
em
cq.co
m
SUBACUTE IEEvolves over weeks to months
Only rarely causes metastatic infection
44
ww
w.m
edicin
em
cq.co
m
VIRIDANS STREPTOCOCCI
Most common organism causing IE
45
ww
w.m
edicin
em
cq.co
m
VIRIDANS STREPTOCOCCI
Originate from the oral cavity
www.medicinemcq.com
46
ww
w.m
edicin
em
cq.co
m
ALPHA-HEMOLYTIC STREPTOCOCCI
Viridans streptococci includes S. salivariusS. mitisS. sanguisS. mutans
47
ww
w.m
edicin
em
cq.co
m
WHY S.VIRIDANS?Transient viridans streptococcal bacteremia induced byEatingTooth-brushing
Can adhere to biologic surfaces.
48
ww
w.m
edicin
em
cq.co
m
COAGULASE-NEGATIVE STAPHYLOCOCCI
Second most common organism
49
ww
w.m
edicin
em
cq.co
m
ENTEROCOCCIThird most common cause
First cause– streptococci Second cause - staphylococcus
50
ww
w.m
edicin
em
cq.co
m
ENTEROCOCCINormal inhabitantGITAnterior urethra
For rest of the slides, visit www.medicinemcq.com > Cardiology
top related