1. Endocarditis usually refers to infection of the endocardium (infective endocarditis) The term can also include noninfective endocarditis, in which sterile platelet and fibrin thrombi form on cardiac valves and adjacent endocardium. Noninfective endocarditis sometimes leads to infective endocarditis Endocarditis can occur at any age. Men are affected about twice as often IV drug abusers and immunocompromised patients are at highest risk

2. Etiology 2 factors are generally required for endocarditis 1. Predisposing abnormality of the endocardium congenital heart defects rheumatic valvular disease bicuspid or calcific aortic valves mitral valve prolapse hypertrophic cardiomyopathy 2. Microorganisms in the bloodstream (bacteremia) Microorganisms that infect the endocardium may originate from distant infected sites (cutaneous abscess, inflamed or infected gums) or have obvious portals of entry such as a central venous catheter or a drug injection site Streptococci and Staphylococcus aureus (80 to 90%) Enterococci Gram-negative bacilli HACEK microorganisms (Haemophilus sp, Actinobacillus actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, and Kingella Kingae) Fungi

3. Symptoms and Signs  Low-grade fever (< 39° C), night sweats, fatigability, malaise, and weight loss. Chills and arthralgias may occur  Symptoms and signs of valvular insufficiency may be a first clue  Retinal emboli can cause hemorrhagic retinal lesions with small white centers (Roth's spots)  Cutaneous manifestations - petechiae (on the conjunctivae, mucous membranes, and distal extremities) -painful erythematous subcutaneous nodules on the tips of digits (Osler's nodes) -hemorrhagic macules on the palms or soles (Janeway lesions)

4. Treatment  IV antibiotics (based on the organism and its susceptibility). Treatment consists of a prolonged course (for 2 to 8 wk) of IV antimicrobial therapy.  Sometimes valve debridement, repair, or replacement. Surgery may be needed for mechanical complications or resistant organisms. Any apparent source of bacteremia must be managed removed

5. Antibiotic Drugs and dosages depend on the microorganism and its antimicrobial susceptibility. Initial therapy before organism identification (but after adequate blood cultures have been obtained) should be broad spectrum to cover all likely organisms. patients with native valves and no IV drug abuse receive ampicillin 500 mg/h continuous IV infusion plus nafcillin 2 g IV q 4 h plus gentamicin 1 mg/kg IV q 8 h

6. Antibiotic  Patients with a prosthetic valve receive vancomycin 15 mg/kg IV q 12 h plus gentamicin 1 mg/kg q 8 h plus rifampin 300 po q 8 h.300 po q 8 h  IV drug abusers receive nafcillin 2 g IV q 4 h  In penicillin-allergic patients require substitution ampicillin of vancomycin 15 mg/kg IV q 12 h.

7. Antibiotic  For right-sided endocarditis caused by methicillin-sensitive S. aureus nafcillin 2 g IV q 4 h plus gentamicin 1 mg/kg IV q 8 h for 2 wk  If endocarditis caused by HACEK microorganisms Ceftriaxone 2 g once/day IV for 4 wk or Ampicillin 12 g/day IV continuously or 2 g q 4 h plus gentamicin 1 mg/kg IV q 8 h for 4 wk

8. Antibiotic  If endocarditis caused by Coliform bacilli ceftriaxone 2 g IV q 12–24 h or ceftazidime 2 g IV q 8 h) plus gentamicin 2 mg/kg IV q 8 h for 4-6 wk  If endocarditis caused Pseudomonas aeruginosa ceftazidime 2 g IV q 8 h or cefepime 2 g IV q 8 h or imipenem 500 mg IV q 6 h plus tobramycin 2.5 mg/kg q 8 h for 6–8 wk amikacin 5 mg/kg q 12 h substituted for tobramycin if bacteria are susceptible