Infective Endocarditis Flashcards
1
Q
IE Incidence
A
- Infective endocarditis
- Uncommon
- Increased incidence in elderly, IDU, and prosthetic heart valves
2
Q
Risk Factors
A
- Congenital heart disease + cyanosis
- Rheumatic heart disease following rheumatic fever
- Mitral valve prolapse with regurgitation
- Degenerative valvular lesions; stenosis, regurgitation
- Prosthetic valves
- IDU
3
Q
IE Pathogenesis
A
- Endothelial surface of heart damaged
- Platelet and fibrin deposition leading to nonbacterial thrombotic endocarditis formation
- Bacteremia results in colonization of endocardial surface
- Gram “+” more likely to adhere to NBTE from adhesion factors
- After colonization, fibrin, platelets, and bacteria continue to aggregate and a “vegetation” forms
4
Q
Heart Valves Involved
A
- Mitral (86%) - most commonly caused by S. viridans when rheumatic heart disease is abnormality
- Aortic (55%) - more acute infections
- Tricuspid (20%) - common site of staph endocarditis in IDU
- Pulmonic (1%)
5
Q
Acute v.s. Subacute
A
- Subacute: indolent infections with less invasive organisms (Viridans), common with prior valvular heart disease
- Acute: fulminant infection following infection of a previously normal valve
6
Q
Non-virulent Organisms
A
- Low grade fever
- Malaise
- Fatigue
- Weight loss
7
Q
Virulent Organisms
A
- High grade fever (common)
- Chills, sweat
- Septic picture
- Embolization complications
8
Q
IE Clinical Features
A
- Heart murmur - common and on a scale of 1-6
- Skin lesions
- Other: renal failure, splenomegaly, back pain, abdominal pain, chest pain, etc.
9
Q
Peripheral Manifestations
A
- Osler nodes: purple/red subcutaneous papules/nodules that appear on toes and fingers and can be painful and tender
- Roth spots retinal hemorrhages usually caused by immune complex mediated vasculitis
- Janeway lesions: hemorrhagic, painless plaque that develop on palms and soles
- Splinter hemorrhages: thin, linear under nailbeds
- Petechiae: small, erythematous hemorrhagic lesions that aren’t painful or tender
- Finger Clubbing: proliferative change in the soft tissue at the ends of fingers
10
Q
Labs + Significant Tests
A
- Blood cultures
- Hematologic: WBC, BUN/SCr
- ESR
- Echocardiogram: TEE more sensitive for detecting vegetation
11
Q
IE + Major Criteria
A
- Blood: two blood cultures positive for typical IE organism
- Echo: Positive for IE, myocardial abscess, development of partial dehiscence of a prosthetic valve, new-onset valvular regurgitation
12
Q
IE + Minor Criteria
A
- Predisposing heart condition or IDU
- Fever > 38C
- Vascular phenomenon
- Immunological phenomenon
- Positive blood culture results not meeting major criteria
- Echo results consistent with IE but no other major criteria
13
Q
Vascular phenomenon
A
- Major arterial emboli
- Septic pulmonary infarcts
- Intracranial hemorrhage
- Conjunctival hemorrhage
- Janeway lesions
14
Q
Immunological Phenomenon
A
- Glomerulonephritis
- Osler nodes
- Roth spots
- Rheumatoid factor
15
Q
Diagnosis
A
- Definite Endocarditis: microorganism by vegetation culture or cardiac abscess confirmed OR meeting 2 major criteria, 1 major and 3 minor criteria, or 5 minor criteria
- Possible Endocarditis: Findings consistent with IE but falls short of definite
- Rejected: Firm alternative diagnosis or resolution of symptoms in less than 4 days or no pathological evidence at surgery or autopsy
