Endocarditis

Endocarditis is an inflammation of the inner layer of the heart, the endocardium. It usually involves the heart valves. Other structures that may be involved include the interventricular septum, the chordae tendineae, the mural endocardium.

Classification
Classification is based on etiology: either infective or non-infective, depending on whether a microorganism is the source of the inflammation or not.

Diagnosis
Echocardiogram, as well as any blood cultures demonstrating the presence of endocarditiscausing microorganisms.

Infectious endocarditis

 * Since the valves of the heart do not receive any blood supply, defensive immune mechanisms (such as white blood cells) cannot directly reach the valves via the bloodstream.
 * If an organism (such as bacteria) attaches to a valve surface and forms a vegetation, the host immune response is blunted.
 * Normally, blood flows smoothly through these valves.
 * If they have been damaged (from rheumatic fever, for example) the risk of bacteria attachment is increased.

Non-Infectious Endocarditis

 * Most commonly found on previously undamaged valves.
 * The vegetations are small, sterile, and tend to aggregate along the edges of the valve or the cusps.
 * Does not cause an inflammation response from the body.

Diagnosis

 * Blood culture (raised inflammatory markers such as erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and white blood cell (WBC) count.


 * Electrocardiography
 * Chest radiograph


 * Echocardiography

Treatment
Antibiotic treatment with intravenous (IV) benzylpenicillin plus IV gentamicin should be initiated immediately if IE is suspected, unless Staphylococcus aureus is suspected, when empirical therapy should be IV vancomycin plus IV gentamicin.

After identification of the causative organism with blood cultures, antibiotic therapy should then be focused on treatment of that organism. Surgical valve replacement.