Endothelial surface is damaged

Platelets and fibrin deposit on damaged endothelium

Bacteremia

Organisms colonize surface

Vegetation of fibrin, platelets, and bacteria forms

Bacterial growth concentrates up to 10^9-10^10

Protect bacteria from the environment

Cause valvular damage

Embolization of septic fragments

Circulating immune complexes

S. aureus, CNS - 1st year post prostetic valve surgery, IV drug users

Viridans group of strep - more common with mitral valve prolapse following dental

Enterococcus - Following genitourinary manipulations

Fever

Dyspnea

Nigh sweats

New Heart murmur

Skin lesions:

Conjunctival Petechiae

Splinter Hemorrhages

Clubbing of fingers

Jeneway lesions

Roth spots

Osler Nodes

Signs and Symptoms

>3 blood cultures at least 1hr apart

Echocardiography - transthoracic, transesophageal

Major:

Positive blood cultures >2/2

Positive Echocardiogram

Minor:

Predisposition to IE

Fever

Vascular Phenomena

Immunologic Phenomena

Microbiologic findings

Duke Criteria:

Definite

Vegetations, major emboli or itracardiac abscess

2 major criteria

1 major and 3 minor

5 minor

Duke Criteria:

Probable

1 major and 1 minor

3 minor

Duke Criteria:

Rejected

Firm alternative diagnosis

Resolution <4 days after antimicrobials

No evidence at surgery

Usual Pathogens in Adults:

Native Valve Non IV drug use

S. aureus, MRSA

Viridans group strep

Enterococcus spp

Usual Pathogens in Adults:

Native Valve IV drug use

Empiric Antibiotic Therapy:

Adult Native Valve Non IVDU

Acute: Vancomycin + Ceftriaxone 2g IV daily -> duration 6 weeks if culture negative; 

Severe Pen allergy: Vancomycin + Gentamicin -> same duration

Usual Pathogens in Adults:

Prosthetic Valve <8 weeks

S. aureus/MRSA

CNS

Usual Pathogens in Adults:

Prosthetic Valve >8 weeks

S. aureus/MRSA

CNS

Viridans group strep

Enteroccocus

Empiric Antimicrobial Therapy:

Prosthetic valve adult (early and late)

Vancomycin 15mg/kg iv q8-12h - 6 wks

Gentamicin 1mg/kg iv q8h - 2 wks

Rifampin 300mg po tid or 600mg bid - 6 wks

Culture negative endocarditis:

potential causes

poor collection technique

difficult to culture organism

previous antimicrobial therapy

heart failure unresponsive to therapy

perivalvular invasive disease

Uncontrolled infection despite maximal antibiotic therapy

significant risk of embolic complications

prosthetic valve infection

Cardiac:

Heart Failure secondary to valvular dysf

AV or bundle branch block

Increased risk of reinfection

Neurologic:

Stroke Syndrome

Systemic Emboli and Slenic Abscess

Life threatening

Certain cardiac conditions predispose pts to infection

Bacteremia with known pathgens occurs with invasive procedures

Therapy proven effective in animal models

Prosthetic Cardiac Valves

Previous Infective Endocarditis

CHD

Cardiac transplant recipients who develop valvulopathy

ABx Prophylaxis

Only for high risk heart defects

Only for dental procedures with manipulation of gingival tissues, or periapical tissue of teeth, or perforation of the oral mucosa

Respiratory Tract or Infected skin, skin structures or muscoloskeletal tissues 

Standard: Amoxicillin

B-lactam allergy: Clindamycin, Azithromycin, Clarithromycin

Give 1hr before dental procedure. 

Standard: Ampicillin 

B-lactam allergy: Clindamycin, Cefazolin or ceftriaxone