Download Native valve endocarditis

INFECTIVE ENDOCARDITIS
Dr. M. A. SOFI
MD; FRCP (London); FRCPEdin; FRCSEdin
Infective endocarditis (IE) is defined as an infection of the
endocardial surface of the heart, which may include one or more
heart valves, the mural endocardium, or a septal defect.
Signs and symptoms
 Fever possibly low-grade
and intermittent
90%.
 Heart murmurs 85%
 Petechiae: Common, but
nonspecific, finding
 Subungual (splinter)
hemorrhages: Dark-red,
linear lesions in the nail
beds
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Osler nodes: Tender
subcutaneous nodules
usually found on the distal
pads of the digits
Janeway lesions: Nontender maculae on the
palms and soles
Roth spots: Retinal
hemorrhages with small,
clear centers; rare
Other signs of IE include the following:
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Splenomegaly
Stiff neck
Delirium
Paralysis,
hemiparesis,
aphasia
• Conjunctival
hemorrhage
•
•
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•
Pallor
Gallops
Rales
Cardiac
arrhythmia
• Pericardial rub
• Pleural friction rub
Patients with IE may have
involvement of other
organs:
• Metastatic infection (eg,
vertebral osteomyelitis),
• Embolic events (eg, focal
neurologic deficits, renal
infarct, splenic infarct).
• Systemic immune reaction
(eg, glomerulonephritis).
• In right-sided endocarditis,
septic pulmonary emboli
may be seen
CXR of a patient with
tricuspid valve endocarditis
Multiple cavitating lung
nodules due to septic
pulmonary emboli.
Petechiae
Janeway lesions
Osler node
Splinter hemorrhage
Native valve endocarditis
The symptoms of early subacute native valve endocarditis are
usually subtle and nonspecific; they include the following:
• Low-grade fever:
Absent in 3-15% of
patients
• Anorexia
• Weight loss
• Influenza-like
syndromes
• Polymyalgia-like
syndromes
• Pleuritic pain
• Syndromes similar to
rheumatic fever, such as
fever, dull sensorium,
headaches
• Abdominal symptoms,
such as right upper
quadrant pain, vomiting,
postprandial distress,
appendicitis-like
symptoms
Diagnosis
The Duke diagnostic criteria, are generally used to make a definitive
diagnosis of IE. The criteria combine the clinical, microbiologic,
pathologic, and echocardiographic characteristics of a specific case
Blood culture criteria for IE:
• Typical microorganism for
infective endocarditis from
two separate blood cultures
• Blood cultures persistently
positive for one of these
organisms, from cultures
drawn more than 12 hours
apart
• Three or more separate
blood cultures drawn at least
1 hour apart
Echocardiographic criteria for
IE
• Oscillating intracardiac mass on
a valve or on supporting
structures, in the path of
regurgitant jets, or on implanted
material.
• Myocardial abscess
• Development of partial
dehiscence of a prosthetic valve
• New-onset valvular
regurgitation
Minor criteria for IE include the following:
Predisposing heart
condition or intravenous
drug use
 Fever of 38°C or higher
Vascular phenomenon:
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Major arterial emboli
Septic pulmonary
infarcts
Mycotic aneurysm
ICH
Janeway lesions
Conjunctival hemorrhage
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Immunologic phenomenon:
 Glomerulonephritis
 Osler nodes
 Roth spots
 Rheumatoid factor
A definitive clinical
diagnosis is based on:
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
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2 major criteria
1 major criterion and 3
minor criteria
5 minor criteria
Native valve endocarditis: Main underlying causes of NVE
 RHD (30% of NVE) Primarily involves the mitral
valve followed by the aortic
valve
Degenerative heart disease:
 Calcific aortic stenosis due to a
bicuspid valve
 Marfan syndrome
 Syphilitic disease
 Mitral valve prolapse with an
associated murmur (20% of
NVE)
 Congenital heart disease
(15% of NVE) - Underlying
etiologies include:
 Patent ductus arteriosus
 Ventricular septal defect
 Tetralogy of Fallot
 Native or surgical highflow lesion.
Approximately 70% of infections in NVE are caused by
Streptococcus species, including S viridans, Streptococcus bovis,
and enterococci. Staphylococcus species cause 25% of cases and
generally demonstrate a more aggressive acute course.
Prosthetic valve endocarditis
Early PVE, which presents shortly after surgery, has a different
bacteriology and prognosis than late PVE, which presents in a
subacute fashion similar to NVE.
Aortic valve prostheses infection  Pericardial tamponade
is particularly associated with:  Peripheral emboli to the CNS
and elsewhere.
 local abscess and fistula
Early PVE may be caused by:
formation
 S aureus and S epidermidis.
 Valvular dehiscence.
These nosocomially acquired
This may lead to:
organisms are often
 Shock
methicillin-resistant ( MRSA).
 Heart failure
 Late disease is commonly
 Heart block
caused by streptococci.
 Shunting of blood to the rght
 Overall, CoNS are the most
atrium
frequent cause of PVE (30%).
IVDA infective endocarditis
Diagnosis in IV drug users can
be difficult and requires a
high index of suspicion.
 2/3 of patients have no
previous history of heart
disease or murmur on
admission.
 A murmur may be absent in
those with tricuspid disease.
 Pulmonary manifestations
may be prominent in
patients with tricuspid
infection:
 1/3 have pleuritic chest
pain, and three quarters
demonstrate chest
radiographic abnormalities.

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S aureus is the most common
(< 50% of cases) etiologic
organism in patients with
IVDA IE.
MRSA accounts for an
increasing portion of S aureus
infections and has been
associated with previous
hospitalizations, long-term
addiction, and non-prescribed
antibiotic use.
Groups A, C, and G
streptococci and enterococci
are also recovered from
patients with IVDA IE.
Differential Diagnoses
• Thrombotic nonbacterial
endocarditis
• Vasculitis
• Temporal arteritis
• Marantic endocarditis
• Connective tissue disease
• Fever of unknown origin
(FUO)
• Intra-abdominal
infections
• Septic pulmonary
infarction
• Tricuspid regurgitation
• Antiphospholipid
Syndrome
• Atrial Myxoma
• Cardiac Neoplasms,
Primary
• Lyme Disease
• Polymyalgia Rheumatica
• Reactive Arthritis
• Systemic Lupus
Erythematosus
Diagnostic work up:
Criterion standard for diagnosis of (IE) is the documentation of a
continuous bacteremia (>30 min in duration) on blood culture results
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CBC (Leukocytosis)
ESR (Elevated in 90%)
BUN
Coagulation Profile
RF (+50%)
Proteinuria
Hematuria
3-5 sets of blood cultures
over 24 hours
• 3 sets may be drawn over 30
minutes (with separate
venipunctures)
• Culture-negative infective
endocarditis
 Vasculitis
 Prior antibiotic therapy
 Fungal infections
 Atypical organisms
Echocardiography: Echocardiography has become diagnostic
method of choice. The diagnosis of IE can never be excluded based on
negative echocardiogram .
TTE
• Sensitivity is 60% for NVE
valvular lesions, 20% in PVE.
TEE
• Can detect the NVE
vegetations of in 90-100%.
• Sensitivity is greater than
90% for PVE.
• Can visualize vegetations of
the Tricuspid valve in more
than 90%.
• Can predict embolic
complications of IE.
• Predictors of systemic
embolization include:
– Large valvular vegetations
(>10 mm in diameter)
– Multiple vegetations
– Mobile but pedunculated
vegetations
– Prolapsing vegetations
 Echocardiography is also highly
useful for detecting abscesses
Treatment
The major goals of therapy
for infective endocarditis
(IE) are:
1. Eradicate the infectious
agent from the thrombus
2. Intra cardiac and extra
cardiac consequences of
IE.
3. Surgical intervention.
4. Emergency care: Correct
diagnosis & stabilization
General Measures:
• Treatment of congestive
heart failure
• Oxygen
• Hemodialysis (in patients
with RF)
• Empiric antibiotic therapy
is chosen based on the
most likely infecting
organisms.
Treatment
• Native valve
endocarditis (NVE):
Penicillin G with
gentamicin for synergistic
coverage of streptococci
• Patients with IVdrug use
are treated with nafcillin
and gentamicin to cover
for MRSA.
• Prosthetic valve
endocarditis (PVE) may
be caused by MRSA or
coagulase-negative
staphylococci (CoNS)
• Patients with culturenegative PVE are usually
given vancomycin and
gentamicin, targeting
enterococcal or CoNS
infections
Approximately 15-25% of patients with IE eventually
require surgery. Indications for surgical intervention in
patients with NVE are as follows:
CHF refractory to
standard medical therapy
• Fungal IE (except that
caused by Histoplasma
capsulatum)
• Persistent sepsis after
72 hours of appropriate
antibiotic Rx
• Recurrent septic
emboli, especially after 2
weeks of antibiotic
treatment
•
• Rupture of an aneurysm
of the sinus of Valsalva
• Conduction disturbances
caused by a septal abscess
• Kissing infection of the
anterior mitral leaflet in
patients aortic valve IE
• Paravalvular abscess and
intracardiac fistula
Prevention of IE:15-25% cases of IE are due to procedures
that produce bacteremia
High risk patients include: Consider prophylaxis in
• Presence of prosthetic
procedures involving:
heart valve
• Manipulation of gingival
• History of endocarditis
tissue or the periapical
• Cardiac transplant
region of teeth.
recipients who develop
cardiac valvulopathy
• Infected skin including
• Congenital heart disease
incision and drainage of an
with a high-pressure
abscess
gradient lesion
• Prophylaxis is no longer
routinely recommended for
GI procedures.