ENDOCARDITISThe Etiology and the Laboratory

Studies

Reşat Özaras, MD, Professor,

Infectious Diseases Dept.

Definition

• Endocarditis: it is an inflammation of the inner layer of the heart, the endocardium.

Clinical Features

• Whom to consider IE– Injection drug users– Prostethic heart valve– Prior IE– Bacteremia– Hemodialysis– HIV infection

Clinical Features

• Wide spectrum of signs&symptoms– Fatigue– Anorexia– Weight loss– Prolonged fever– Dizziness– Dyspnea– …..

PE

• Murmur

• Splenomegaly

• Findings of complications (emboli etc..)

IE: Clinical Classification

• Acute IE

Main etiology: S. aureus

Mortality (untreated) : < 2 months, 100%

• Subacute—chronic IE

Main etiology: Viridans streptococci

Mortality (untreated) : < 1 year, 100%

Classification According to the Valve

• Native Valve Endocarditis

• Prosthetic Valve Endocarditis

• Clinical criteria Using specific definitions :

– 2 major criteria OR– 1 major and 3 minor criteria OR– 5 minor criteria

• Possible IE• 1 major criterion and 1 minor criterion

OR 3 minor criteria

Major Diagnostic Criteria

• Positive blood culture for typical infective endocarditis

• Echocardiography findings – with oscillating intracardiac mass – abscess

Search Google for echo videos!

• http://www.echojournal.org/video/379/Aortic-valve-vegetation-1-of-2

Minor Diagnostic Criteria 

• Predisposing heart condition or intravenous drug use     • Temp > 38.0° C • Vascular phenomena: arterial emboli, pulmonary

infarcts, mycotic aneurysms, intracranial bleed, conjunctival hemorrhages, Janeway lesions     

• Immunologic phenomena: glomerulonephritis, Osler nodes, Roth spots, rheumatoid factor     

• Microbiological evidence: positive blood culture but does not meet a major criterion   

• Echocardiographic findings: consistent with endocarditis but do not meet a major criterion

• Clinical criteria Using specific definitions :

– 2 major criteria OR– 1 major and 3 minor criteria OR– 5 minor criteria

• Possible IE• 1 major criterion and 1 minor criterion

OR 3 minor criteria

IE: Etiology NV PV

1-Streptococci: ~%50 ~40%

2-S. aureus: 3-Enterococci: 4-Coagulase-neg Staph: ~%5 ~70% 5-Gram-Neg Bacilli:6-Fungus (Candida): 7-Diphteroids: 8-Polymicrobial: 9-Culture-neg./HACEK:

Our cases with IE

1-Viridans streptococci (8) (40%) 2-S. aureus (MSSA) (4) (20%) 3-Enterococci (2) (10%) 4-MSSE (1) (5%) 5-Anaerobs (1) 6-S. typhi (1) 7-Brucella (1) 8-Culture-negative (2)

IE: Streptococci

• Viridans streptococci (-hemolytic) (the most frequent ones)

1-S. sanguis

2-S. mutans

3-S. mitis• S. bovis (non-hemolytic)

Staphylococci

• S. aureus • S. epidermidis

DiagnosticsClinical Samples

• Blood• Serum (for serology)• Embolus, abscess, or removed infected valve

(for microbiological and histolgical studies)

IE: S. aureus

• Fever+S.aureus: consider IE (echo.)• Fever+S.aureus in injection drug user:

consider right side (tricuspid) IE (echo.)

Culture-negative IE

• Failure to yield any m.o. with automated blood culture systems within 7 days

• ~5%• Use of antibiotics• Coxiella burnetii and Bartonella

IE: Serology

1-Brucella

2-Coxiella burnetii

3-Bartonella

Treatment

• Antibiotics• Surgery may be needed

IE: Mortality is ~30

Major systemic emboli

Heart Failure

Septic shock

Complications

• Cardiac • Septic • Embolic • Neurologic • Musculoskeletal • Renal • Associated with medical treatment

Complications

• Embolic (eg, cerebral infarct)

• Local spread of infection (eg, heart valve destruction)

• Metastatic infection (eg, vertebral osteomyelitis)

• Immune-mediated damage (eg, glomerulonephritis