Infective Endocarditis (IE) is a serious heart infection, primarily affecting the endocardium and heart valves, linked to high morbidity and mortality rates. The disease can be classified into native and prosthetic valve infections, with risk factors including dental procedures, intravenous drug use, and prior heart conditions. Diagnosis relies on clinical features and laboratory tests, with treatment typically involving prolonged antibiotic therapy and possible surgical intervention for complications.

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INFECTIVE
ENDOCARDITIS
BY: DR. K.S.K JUSU
DEPARTMENT OF INTERNAL MEDICINE
MAKENI SCHOOL OF CLINICAL SCIENCES

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Definition of IE
 Serious infection of the endocardium of the heart
 Particularly the heart vavle associated with high
degree of illness and death
 Generally associated with altered and abnormal
heart architecture, in combination with exposure
to bacteria through trauma and potentially high
risk activities involving transient bacteraemia.

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Classification of IE
 Native valve IE
 Prosthetic valve IE
 Intravenous drug abuse IE
 Nosocomial IE

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Prosthetic valve endocarditis( PVE)
 10-30% 0f all cases in developed nations
 Early PVE occurs within 60days
. Nosocomial( s. epidermidis predominate)
 Late PVE occurs after 60days
. Community( same organisms as NVE)

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Pathology……..
 NVE infection is largely confined to leaflets
 PVE infection commonly extends beyond valve ring eg septal abscesses and
prosthetic dehiscence
 Invasive infection more common in aortic position and if onset is early

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Classification cont………
 Acute
- toxic presentation
- progressive valve distruction
- metastatic infection developing in days to weeks
- commonly cause by staph. Aureus
 Subacute
- Mild toxicity
- Presentation over weeks to months
- Rarely lead to metastatic infection
- Most commonly by strep. Viridan or enterococcus

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Risk factors of IE
 Dental manipulation
 Dental disease
 Brushing teeth
 Extracardiac infection
 Instrumentation ( urinary tract, iv infusion, GI tract)
 Cardiac surgery
 Iv drug use
 Rheumatic heart disease
 Congenital heart disease

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Risk factors cont…..
 RHD
 Mitral site more common in women and aortic site in men
 Congenital heart disease, 10-20% in young adults and 8% in older adults,
common with PDA, VSD,AORTIC valve
 Iv drug abuse, high tendency to involve right sided valves
distribution in clinical series
-46-78% tricuspid
-24-32% mitral
-8-19% aortic
Staph aureus predominant organism

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Infecting organisms in IE
 Streptococci 60-80%
- alpha hemolytic strep( viridans- s.mitis, s. oralis) 30-40% subacute
- enterococci( E.faecalis) 5-18% subacute
- beta hemolytic strep( eg Gp A strep)- rare acute
 Staphylococci 20-35%
- staph aureus 10-27% acute
- coagulase negative staph( staph epidermidis)1-3%, mainly prosthetic valve risk, subacute)
 fungi
-candida-IVDU at risk
-aspergillus-rare
 Gram negative bacteria-rare
 Culture negative endocarditis HACEK, Q-fever-cases do occur, subacute

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Infecting organism cont……
 Common bacteria
- alpha haemolytic strep( s. viridans- s. mitis, s.sanguis)
- enterococci( E.Faecalis) all subacute
- coagulase neg. staph- prosthetic valves
 Less common bacteria
- staph aureus
- beta hemolytic strept all acute
- strept pneumonia
 Not so common
- fungi ,pseudomonas, HACEK group organisms

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Infecting organisms cont……
 HACEK GROUP ORGANISMS
- Haemophilus spp
- actinobacillus
actinomycetemcomitans
- Cardiobacterium hominis
- Eikenella corrodens
- Kingella kingae

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pathophysiology
 Turbulent blood flow within the heart- most often but not always
 Turbulent blood flow disrupts valve surface to produce suitable sticky site for
bacterial attachment
 Platelet deposition+fibrin may lead to non bacterial thrombus or vegetation
 Bacteraemia- delivers organisms to the damaged (sticky) endocardial surface
resulting in adherence and colonization
 Eventual invasion of valve leaflets results in infected vegetation.

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Differences between acute and subacute
bacterial endocarditis
features acute subacute
Underlying heart disease Heart may be normal RHD, CHD, etc
organisms Staph
aureus,pneumococcus
s. Pyogenes
enterococcus
Viridans
Strep
enterococcus
therapy Prompt vigorious and
initiated on empirical
ground
Can often be delayed
until culture reports and
susceptibilities available

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Clinical features
 Fever
 Murmurs
 Petechial and cutaneous manifestations. Roth spots, conjunctival and mucosal
petechiae,splinter hemorrhages, osler nodes and janeway lesions
 Splenomegaly
 Embolism
 CHF
 General: weight loss, anorexia, loss of libido

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Clinical features specific to acute and
subacute
acute subacute
High grade fever and chills Low grade fever
SOB anorexia
arthralgias/myalgias Weight loss
Abdominal pain fatigue
Pleuritic chest pain Arthralgias/myalgias
Back pain Abdominal pain, N/V

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Laboratory features of IE
 Anemia
 Elevated WBCs
 Elevated ESR
 Microscopic hematuria
 bacteremia

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Lab……….
BLOOD CULTURES REMAIN A CORNER STONE OF THE DIAGNOSIS OF IE CASES AND
SHOULD BE TAKEN PRIOR TO STARTING ANTIBIOTICS IN ALL CASES
Minimum of three blood cultures( ideally spread over 24hours) from three
separate venipuncture sites

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Additional tests
 CBC
 Complement levels(c3,c4)
 RF
 Urinalysis

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Imaging
 CXR- multiple focal infilterates and calcification of heart valves
 ECG- look for evidence of ischaemia,arrhythmias
 echocardiography

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Indications for echocardiography
 Transthoracic echocardiography( TTE)
- 1st
.line if suspected IE
- native valves
 Trans esophageal echocardiography( TEE)
- prosthetic valve
- intracardiac complications
- inadequate TTE

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Treatment
 Parenteral antibiotics- high serum concentration and prolonged treatment to
kill dormant bacteria clustered in vegetation, at least 4-6weeks
 Surgery for intracardiac complications/paravalve abscess

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complications
 Embolic
 Local spread of infection
 Metastatic spread of infection
 Formation of immune complexes

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THANKS FOR LISTENING