Infective Endocarditis

INFECTIVE ENDOCARDITIS Mr. ALFRIN ANTONY Asst. Lecturer DEPARTMENT OF PATHOLOGY +919738286092

ENDOCARDITIS 

Inflamation of endocardium A. Non-Infective Rheumatic Endocarditis Atypical Verrucous Endocarditis Non bacterial thrombotic Endocarditis B. Infective Bacterial endocarditis Other Infective types (tuberculosis, syphilitic, fungal, viral, rickettsial)

Infective Endocarditis   

Febrile illness Persistent bacteremia Characteristic lesion of microbial infection of the endothelial surface of the heart the vegetation Variable in size  Amorphous mass of fibrin & platelets  Abundant organisms  Few inflammatory cells 

BACTERIAL ENDOCARITIS 

DEFINITION:- Bacterial endocarditis is serious infection of the valvular and mural endocardium caused by different forms of bacteria (other than tubercle bacilli and bacterial micro organisms) and characterized by typical infected and friable vegetations

CLASSIFICATION depending on severity Acute Acute bacterial endocarditis:- is the fulminant and obstructive acute infection of the endocardium by highly virulent bacteria in a previously normal heart (fatal2-6 weeks)

Subacute Subacute bacterial endocarditis is caused by less virulent bacteria in a previously diseased heart and has a gradual down hill course in a period of 6 weeks to months-years

INCIDENCE 

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Bacterial endocaditis may occur at any age Most cases more than 50yeas Males > females

ETIOLOGY 1.Infective agents 2.

3. 4. 5. 6.

ABE Staphylococci (staphylococcus aureus) Pneumococci Gonococci Beeta-streptococci Enterococci

2.

3.

4.

5.

6.

SABE Streptococci with low virulence Streptococcus viridans (mouth) Streptococci bovis (stomach) Streptococcus pneumoniae Staphylococcus epidermidis

Predisposing factors 1.

2. 3.

Bacteraemia, septicemia and pyaemia Underlying heart disease Impaired host defence

Pathogenesis 1.

2.

3.

The circulating bacteria are lodged much more frequently on previously damaged valves from disease, chiefly RHD nad CHD than healthy valves Conditions producing haemodynamic stress on the valves are liable to cause damage to the endocardium, favouring the formation platelets thrombi which gets infected from circulating bacteria Non-bacterial thrombotic endocarditis occurs from prolonged stress

PATHOLOGIC CHANGES 

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MACROSCOPICALLY Lesions are in mitral>aortic>both > right heart SABE > ABE

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MICROSCOPICALLY The out layer consists of eosinophilic material composed of fibrin platelets Underneath layer is the basophilic zone containing colonies of bacteria The deeper zone consists of nonspecific inflammatory reaction

Symptoms 

Acute 

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High grade fever and chills Arthralgias/ myalgias Abdominal pain Pleuritic chest pain Back pain

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Subacute     

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Low grade fever Anorexia Weight loss Fatigue Arthralgias/ myalgias Abdominal pain

The onset of symptoms is usually ~2 weeks or less from the initiating bacteremia

Signs   

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Fever Heart murmur Nonspecific signs – petechiae, subungal or “splinter” hemorrhages, clubbing, splenomegaly, neurologic changes More specific signs - Osler’s Nodes, Janeway lesions, and Roth Spots

Petechiae 1. Nonspecific 2. Often located on extremities or mucous membranes dermatology.about.com/.../ blpetechiaephoto.htm

Photo credit, Josh Fierer, M.D. medicine.ucsd.edu/clinicalimg/ Eye-Petechiae.html

Harden Library for the Health Sciences www.lib.uiowa.edu/ hardin/ md/cdc/3184.html

Splinter Hemorrhage

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

Osler’s Nodes

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

Janeway Lesions

Janeway Lesions

1. More specific 2. Erythematous, blanching macules 3. Nonpainful 4. Located on palms and soles

Subconjunctival Hemorrhages

COMPLICATIONS  

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CARDIAC Valvular stenosis or insufficiency Perforation, rupture and aneurysm of valve and leaflets Abscesses in the valve ring Myocardial abscesses Suppurative pericarditis Cardiac failure

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EXTRA CARDIAC Infracts in spleen, kidneys and brain Pulmonory abscesses Petechiae (skin conjunctiva) Osler’s nodes(SABE) Janeway’s spots (ABE)

Local Spread of Infection

Acute S. aureus IE with perforation of the aortic valve and aortic valve vegetations.

Acute S. aureus IE with mitral valve ring abscess extending into myocardium.

Septic Pulmonary Emboli

http://www.emedicine.com/emerg/topic164.htm

Septic Retinal Embolus

Roth’s Spots

TUBERCULOUS ENDOCARDITIS It is characterized by presence of typical tubeculosis on the valvular as well as mural endocardium and form tuberculosis thrombo emboli

Syphilis endocaditis 

Aortic valvular incompitance (severe)

Fungal endocaditis Oppurtunistic

fungal infections like candidiasis ans aspergillosis are seen I patients receiving long term anti biotic therapy

Viral endocarditis 

Only in experiment

Rickettsial endocarditis Another

rare cause of endocaditis is form infection in Q fever