Endocarditis

Aortic and mitral > tricuspid (IV drug users) >> pulmonic. Bacteremia characteristic, and predisposes to. Regurgitant jet damage (mitral valve prolapse WITH regurgitation) will predispose, as will pre-existing valvular damage from rheumatic fever.

Acute: Staph aureus, beta-hemolytic strep -- Group A, Group B, Group G, S. pneumoniae (in context of pneumonia, developing world), N. gonorrhea (rare). Subacute: strep. viridans, Enterococcus, Group D strep -- onset over weeks to months, low grade fever, night sweats, weight loss.

HACEK organisms: slow-growing causes of endocarditis. Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, Kingella.

Pathogenesis. Initial injury, get thrombus, bacteria grows in fibrin-platelet matrices (hence gram negative endocarditis is rare, because they don't stick as well as gram positives). Build-up over time, "cauliflower" forms. Need long course of antibiotics to "clear away layers." Need BACTERICIDAL drugs.

FROM JANE:

Fever
Roth's spots, white spots on retina, surrounded by hemorrhage, due to immune complex vasculitis
Osler's nodes, immune complex related, tender
Murmur

Janeway lesions, immune complex related, painless erythematous lesions on palm or sole
Anemia (of chronic disease)

Nail-bed splinter hemorrhages
Emboli, can be septic pulmonary emboli if right-sided

Treatment: Penicillin G, Ceftriaxone +/- gentamicin (aminoglycoside synergistic) is 1st line. Synergy is especially for important for enterococcus because it is intrinsically resistant to penicillin. Vancomycin if allergic to above. For VRE, need to treat with daptomycin or linezolid +/- gentamicin.

S. bovis -- also think colon cancer.

Complications of acute endocarditis: brain abscesses, abscess going into conduction system -- heart block and death. Treatment for acute: nafcillin/cefazolin + gentamicin for MSSA; vancomycin + gentamicin for MRSA (also consider rifampin, daptomycin, linezolid as needed); penicillin G / ceftriaxone for beta-hemolytic strep.

Prophylaxis a good idea for some high risk groups post dental procedures.

Whipple's disease (Tropheryma whipplei) can cause endocarditis. Looks for PAS-positive macrophages on histology.