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Infective endocarditis
- 1. Infective Endocarditis Dr.Khalid Hama salih, MD Pediatrics specialist M.B.Ch. D. C.H B.F.I.B.M.S.ped
- 2. Definition Infectious Endocarditis (IE): an infection of the heart’s endocardial surface Classified into four groups: – Native Valve IE – Prosthetic Valve IE – Intravenous drug abuse (IVDA) IE – Nosocomial IE
- 3. Epidemiology Incidence difficult to ascertain and varies according to location Much more common in males than in females May occur in persons of any age and increasingly common in elderly Mortality ranges from 20-30%
- 4. Risk Factors Artificial heart valves and pacemakers Acquired heart defects – Calcific aortic stenosis – Mitral valve prolapse with regurgitation Congenital heart defects Intravascular catheters
- 5. Infecting Organisms Common bacteria – S. aureus – Streptococci – Enterococci Not so common: – Fungi – Pseudomonas – HACEK group - Haemophilus spp,. Actinobacillus actinomycete comitants, Cardiobacterium hominis, Eikenella spp, and Kingella kingae.
- 6. Pathophysiology Turbulent blood flow disrupts the endocardium making it “sticky” n Bacteremia delivers the organisms to the endocardial surface – Adherence of the organisms to the endocardial surface – Eventual invasion of the valvular leaflets
- 7. SIGNS: SYMPTOMS: Elevated temperature Fever, Chills Tachycardia Night Embolic phenomena (Roth sweats spots, petechiae, splinter Weight loss, Malaise hemorrhages, Osler nodes, CNS or ocular lesions) CNS:manifestations(strok Janeway lesions e,seizures,headache) Splenomegaly Dyspnea Arthritis Heart failure Chest and abdominal Arrhythmias pain Metastatic infection Arthralgia, myalgia (arthritis, meningitis, mycotic arterial aneurysm, pericarditis, abscesses) Clubbing
- 8. Petechiae 1. Nonspecific 2. Often located on extremities or mucous membranes dermatology.about.com/.../ blpetechiaephoto.htm Harden Library for the Health Sciences Photo credit, Josh Fierer, M.D. www.lib.uiowa.edu/ hardin/ medicine.ucsd.edu/clinicalimg/ Eye-Petechiae.html md/cdc/3184.html
- 9. Splinter Hemorrhages 1. Nonspecific 2. Nonblanching 3. Linear reddish-brown lesions found under the nail bed 4. Usually do NOT extend the entire length of the nail
- 10. Osler’s Nodes American College of Rheumatology webrheum.bham.ac.uk/.../ default/pages/3b5.htm www.meddean.luc.edu/.../ Hand10/Hand10dx.html 1. More specific 2. Painful and erythematous nodules 3. Located on pulp of fingers and toes 4. More common in subacute IE
- 11. Janeway Lesions 1. More specific 2. Erythematous, blanching macules 3. Nonpainful 4. Located on palms and soles
- 12. Investigation: Renal failure: azotemia, Positive blood culture highcreatinine(glomerulon ephritis) Elevated erythrocyte sedimentation rate. Chest radiograph: bilateral infiltrates,,pleural Elevated C-reactive protein effusions. Anemia Echocardiographic Leukocytosis evidence of valve Hypergammaglobulinemia vegetations, prosthetic Hypocomplementemia valve dysfunction or leak, Hematuria myocardial abscess, new- onset valve insufficiency
- 13. Duke criteria :- Major criteria include (1) positive blood cultures (two separate cultures for a usual pathogen) and (2) evidence of endocarditis on echocardiography Minor criteria include: predisposing conditions fever embolic-vascular signs immune complex phenomena a single positive blood culture or serologic evidence of infection, and echocardiographic signs not meeting the major criteria. NB/ Two major criteria, one major and three minor, or five minor criteria suggest definite endocarditis
- 14. Treatment Parenteral antibiotics – High serum concentrations to penetrate vegetations – Prolonged treatment to kill dormant bacteria clustered in vegetations 4–6 wk . Surgery – Intracardiac complications Surveillance blood cultures
- 15. Poor Prognostic Factors Female Diabetes mellitus S. aureus Low serum albumen Vegetation size Heart failure Aortic valve Paravalvular abscess Prosthetic valve Embolic events Older age
- 16. PREVENTION Antimicrobial prophylaxis before various procedures and other forms of dental manipulation may reduce the incidence of infective endocarditis in susceptible patients
Notes de l'éditeur
- There is an estimated 10-15,000 new cases of IE diagnosed in the U.S. each year, although the exact incidence of IE is difficult to ascertain. IE is a relatively uncommon disease, is not a reportable disease, and different case definitions have existed throughout the years. Furthermore, the incidence varies greatly depending on geographic regions. IE is more common among males. The male:female ratio varies from 2:1 to 9:1 depending on the source. In the past, IE was a disease of children and young adults. It predominantly affected children with congenital heart disease and adults with rheumatic heart disease. Today, IE commonly affects the elderly, with almost 50% of cases in the U.S. occurring in patients over the age of 60. This may be due to the decreasing incidence of rheumatic heart disease and the increasing proportion of elderly in the U.S. Mortality from IE remains high, and ranges from 20-30% despite newer antibiotics and surgical options.
- The top three risk factors for IE include, IVDA, prosthetic heart valves, and structural heart disease. IVDA – one large study of IVDAs found that the use of cocaine was associated with a higher risk of IE than other injectable drugs. The most significant risk factor for right-sided IE is IVDA, although left sided disease is quite common among IVDAs. The most common infecting organism is clearly S. aureus, particularly in right-sided infection. Prosthetic valve IE comprises a small proportion of all cases of IE and occurs in only 1% of all patients with artificial heart valves. The greatest risk is in the first year following valve replacement. Structural heart disease – approximately ¾ of all cases of IE occur in patients with preexisting structural heart abnormalities. The most common underlying heart abnormalities include mitral valve prolapse with mitral regurgitation and aortic stenosis. The most common congenital heart defects include Tetralogy of Fallot, bicuspid aortic valves, coarctation of the aorta, VSDs, and patent ductus arteriosus. In general, the higher the gradient of the valvular insufficiency, the higher the risk of IE. One of the greatest risk factors of all is a prior episode of IE. Some studies have documented recurrence as high as 9%.
- Staphlococcal and Streptococcal organisms comprise over 80% of all infecting organisms.
- IE often occurs when there is an underlying cardiac abnormality that creates a high-low pressure gradient. The resultant turbulent blood flow disrupts the endocardial surface by peeling away the endothelium. The body’s natural response to endothelial damage is to repair it by laying down a sticky platelet-fibrin meshwork, which is a nidus for infection. Temporary bacteremia delivers the offending organism to the endocardial surface where is sticks to the platelet-fibrin meshwork. This festers into an infection that eventually invades the cardiac valves. The pathophysiology is slightly different with IVDA. It has been postulated that repeated injections of drugs and particulate material causes microtrauma to the cardiac valves, thereby starting the infection cascade.
- Subungal hemorrhages that extend the entire length of the nail or are primarily located at the proximal end of the nail (near the cuticle) are like due to trauma.