Endocarditis

Risk Factors

1. IVDA
   1. Most significant risk factor for right-sided disease
2. Prosthetic heart valve
3. Structural heart disease
4. Hemodialysis

Work-Up

1. History
   1. Recent source of bacteremia?
      1. Indwelling catheters, IVDA
2. Physical Exam
   1. Cardiac, fundi, conjunctivae, skin, digits,
3. Labs
   1. Blood Cx
      1. All patients with S. aureus bacteremia should be evaluated for IE
   2. CBC
      1. Staphylococcal endocarditis: Leukocytosis +/- thrombocytopenia
      2. Subacute endocarditis: WBC may be normal or elevated
   3. UA
      1. C/w glomerulonephritis
4. ECG
   1. Evidence of ischemia, heart block
5. CXR
   1. Septic pulmonary emboli
6. TTE
   1. Low Sn, high Sp

Pathology

1. S. Virdans - most common
2. S. Epidermidis (coag neg strep) - most common for prosthetic valve

Diagnosis

1. Duke Criteria
   1. 2 major criteria OR
   2. 1 major and 3 minor criteria OR
   3. 5 minor criteria
2. Major Criteria
   1. Positive blood culture for infective endocarditis
      1. S. aureus, S. viridans, S. bovis, Enterococci, HACEK
   2. Evidence of endocardial involvement
      1. TEE + or new valvular regurgitation
3. Minor Criteria
   1. Predisposition - predisposing heart condition or IVDA
   2. Fever - 38.0 C (100.4 F)
   3. Vascular phenomena
      1. Arterial emboli, pulmonary infarcts, mycotic aneurysm, ICH, conjunctival hemorrhage, Janeway lesions
   4. Immunologic phenomena - glomerulonephritis, Osler's nodes, Roth spots, rheumatoid factor
   5. Microbiologic evidence - positive blood culture but not meeting major criterion as noted previously
   6. Echo findings: consistent with IE but do not meet a major criterion as noted above

Treatment

1. Antibiotics
   1. Only bactericidal agents are effective in treating endocarditis
      1. Vancomycin

Complications

1. Cardiac
   1. Heart Failure
      1. Most common cause of death due to IE
   2. Perivalvular Abscess
2. Embolic
   1. CVA
   2. Blindness
   3. Painful, ischemic extremities
   4. Unusual pain sydromes (due to splenic or renal infarction)
   5. Hypoxia
   6. Paralysis
   7. MI
3. Neurologic
   1. Embolic stroke
   2. Acute encephalopathy
   3. Meningoencephalitis
   4. Purulent or aseptic meningitis
   5. Cerebral hemorrhage
   6. Seizure
4. Renal
   1. Infarction
   2. Glomerulonephritis
5. Musculoskeletal
   1. Vertebral osteomyelitis

Source

• UpToDate
• Harwood-Nuss