INFECTIVE ENDOCARDITI
S
ByLIKHILA ABRAHAM
Definition Infective endocarditis (IE) is defined as an infection of the endocardial surface of the heart, which may include one or more heart valves, the mural endocardium, or a septal defect. Its intracardiac effects include severe valvular insufficiency, which may lead to intractable congestive heart failure and myocardial abscesses. If left untreated, IE is generally fatal.(medscape)
Infective endocarditis (IE) is a microbial infection of the endothelial surface of the heart or iatrogenic foreign bodies like prosthetic valves or other intracardiac devices
Types Native valve endocarditis (NVE), acute and subacuteProsthetic valve endocarditis (PVE),[10] early and lateIntravenous drug abuse (IVDA) endocarditis
•Risk factors •Structural heart disease–Rheumatic, congenital, aging–Prosthetic heart valves•Injected drug use•Invasive procedures (Intracardiac pacemaker, ICD , AV Fistula)•Indwelling vascular devices•Other infection with bacteremia (e.g. pneumonia, meningitis)•Immunocompromised states•History of infective endocarditis
BacterialStaphylococcus aureus followed by Streptococci of the viridans group and Coagulase negativ Staphylococci are the three most common organisms responsible for infective endocarditis. Other Streptococci and Enterococci are also a frequent cause of infective endocarditis.
Fungal and Viral
Candida albicans, a yeast, is associated with endocarditis in IV drug users and immunocompromised patients. Other fungi demonstrated to cause endocarditis are Histoplasma capsulatum and Aspergillus
HACEK organismsHemophilus, Actinobacillus, Cardiobacterium, Eikenella, Kingella
Nonbacterial Thrombotic Endocarditis
Endothelial injuryHypercoagulable state
Lesions seen at coaptation points of valves
Atrial surface mitral/tricuspidVentricular surface aortic/pulmonic
Clinical features
•Symptoms–Fever, sweats, chills–Anorexia, malaise, weight loss•Signs–Anemia (normochromic, normocytic)–Splenomegaly–Microscopic hematuria, proteinuria–New or changing heart murmur, CHF–Embolic or immunologic dermatologic signs–Hypergammaglobulinemia, elevated ESR, CRP, RF
Cardiac Pathologic Changes Vegetations on valve closure lines Destruction and perforation of valve leaflet Rupture of chordae tendinae,
intraventricular septum, papillary muscles Valve ring abscess Myocardial abscess Conduction abnormalities
S. Aureus mitral valve vegetation, anterior leaflet
Pathologic Changes
Kidney◦ Immune complex glomerulonephritis◦ Emboli with infarction, abscess
Aortic mycotic aneurysms
Pathologic Changes
Splenic enlargement, infarction Septic or bland pulmonary embolism Skin
◦ Petechiae◦ Osler nodes: diffuse infiltrate of neutrophils,
and monocytes in the dermal vessels with immune complex deposition. Tender and erythematous
◦ Janeway lesions: septic emboli with bacteria, neutrophils and S/C hemorrhage and necrosis. Blanching and non-tender. Palms and soles
Splinter Hemorrhages
1. Nonspecific2. Nonblanching3. Linear reddish-brown lesions found under the nail bed4. Usually do NOT extend the entire length of the nail
Osler’s Nodes
1. More specific2. Painful and erythematous nodules3. Located on pulp of fingers and toes4. More common in subacute IE
Janeway Lesions
1. More specific2. Erythematous, blanching macules 3. Nonpainful4. Located on palms and soles
Roth spots
Modified Duke Criteria
Two major criteria, OR One major and three minor criteria, ORFive minor criteria allows a clinicaldiagnosis of definite endocarditis.
Other tests
Electrocardiogram◦ Conduction delays◦ Ischemia or infarction
Chest X-ray◦ Septic emboli in right-sided IE◦ Valve calcification◦ CHF
Antimicrobial Therapy
Blood culture become sterile within 2 days Fever resolves in 4 to 7 days If fever persists despite 7 days of antibiotics
evaluate for paravalvular or extracardiac abscess
Combination therapy most important for◦ Shorter course regimens◦ Enterococcal endocarditis◦ Prosthetic valve infections
Streptococci susceptible to pencillin
NVE
Fungal◦ Amphotericin◦ Fluconazole◦ Caspofungin, little data◦ Surgery usually necessary 1-2 weeks into
treatment