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, or the surfaces of intracardiac devices. Endocarditis is characterized by lesions, known as ''
vegetations'', which is a mass of
platelets,
fibrin
Fibrin (also called Factor Ia) is a fibrous, non-globular protein involved in the clotting of blood. It is formed by the action of the protease thrombin on fibrinogen, which causes it to polymerize. The polymerized fibrin, together with platele ...
,
microcolonies of microorganisms, and scant inflammatory cells.
In the
subacute
In medicine, describing a disease as acute denotes that it is of short duration and, as a corollary of that, of recent onset. The quantification of how much time constitutes "short" and "recent" varies by disease and by context, but the core deno ...
form of infective endocarditis, the vegetation may also include a center of
granulomatous tissue, which may fibrose or calcify.
There are several ways to classify endocarditis. The simplest classification is based on cause: either ''infective'' or ''non-infective'', depending on whether a
microorganism is the source of the inflammation or not. Regardless, the diagnosis of endocarditis is based on clinical features, investigations such as an
echocardiogram, and
blood cultures demonstrating the presence of endocarditis-causing microorganisms.
Signs and symptoms include fever, chills, sweating, malaise, weakness, anorexia, weight loss,
splenomegaly, flu-like feeling, cardiac murmur, heart failure,
petechia
A petechia () is a small red or purple spot (≤4 mm in diameter) that can appear on the skin, conjunctiva, retina, and Mucous membrane, mucous membranes which is caused by haemorrhage of capillaries. The word is derived from Italian , 'freckle,' ...
(red spots on the skin),
Osler's node
Osler's nodes are painful, red, raised lesions found on the hands and feet. They are associated with a number of conditions, including infective endocarditis, and are caused by immune complex deposition. Their presence is one definition of Osler' ...
s (subcutaneous nodules found on hands and feet),
Janeway lesion
Janeway lesions are rare, non- tender, small erythematous or haemorrhagic macular, papular or nodular lesions on the palms or soles only a few millimeters in diameter that are associated with infective endocarditis and often indistinguishable fro ...
s (nodular lesions on palms and soles), and
Roth's spots (retinal hemorrhages).
Infective endocarditis
Infective endocarditis is an
infection of the
inner surface of the heart, usually the
valves.
[ Symptoms may include fever, small areas of bleeding into the skin, heart murmur, feeling tired, and low red blood cells.]heart failure
Heart failure (HF), also known as congestive heart failure (CHF), is a syndrome, a group of signs and symptoms caused by an impairment of the heart's blood pumping function. Symptoms typically include shortness of breath, excessive fatigue, a ...
, stroke
A stroke is a medical condition in which poor blood flow to the brain causes cell death. There are two main types of stroke: ischemic, due to lack of blood flow, and hemorrhagic, due to bleeding. Both cause parts of the brain to stop functionin ...
, and kidney failure.[
The cause is typically a bacterial infection and less commonly a ]fungal infection
Fungal infection, also known as mycosis, is disease caused by fungi. Different types are traditionally divided according to the part of the body affected; superficial, subcutaneous, and systemic. Superficial fungal infections include common ti ...
.[ Risk factors include valvular heart disease including rheumatic disease, congenital heart disease, artificial valves, hemodialysis, intravenous drug use, and electronic pacemakers.][ The bacterial most commonly involved are ]streptococci
''Streptococcus'' is a genus of gram-positive ' (plural ) or spherical bacteria that belongs to the family Streptococcaceae, within the order Lactobacillales (lactic acid bacteria), in the phylum Bacillota. Cell division in streptococci occurs ...
or staphylococci.[
The diagnosis of infective endocarditis relies on the ]Duke criteria
Infective endocarditis is an infection of the inner surface of the heart, usually the valves. Signs and symptoms may include fever, small areas of bleeding into the skin, heart murmur, feeling tired, and low red blood cell count. Complication ...
, which were originally described in 1994 and modified in 2000. Clinical features and microbiological examinations are the first steps to diagnose an infective endocarditis. The imaging is also crucial. Echocardiography is the cornerstone of imaging modality in the diagnosis of infective endocarditis. Alternative imaging modalities as computer tomography, magnetic resonance imaging, and positron emission tomography/computer tomography (PET/CT) with 2- 8Fluorodeoxyglucose (FDG) are playing an increasing role in the diagnosis and management of infective endocarditis.
The usefulness of antibiotics following dental procedures for prevention is unclear.[ Treatment is generally with intravenous antibiotics.][ The choice of antibiotics is based on the blood cultures.][ Occasionally heart surgery is required.][
The number of people affected is about 5 per 100,000 per year.][ Rates, however, vary between regions of the world.][ Males are affected more often than females.][ The risk of death among those infected is about 25%.][
]
Non-infective endocarditis
Nonbacterial thrombotic endocarditis
Nonbacterial thrombotic endocarditis (NBTE) is a form of endocarditis in which small sterile vegetations are deposited on the valve leaflets. Formerly known as marantic endocarditis, which comes from the Greek , meaning "wasting away". The term ...
(NBTE) is most commonly found on previously undamaged valves.[ As opposed to infective endocarditis, the vegetations in NBTE are small, sterile, and tend to aggregate along the edges of the valve or the cusps.][ Also unlike infective endocarditis, NBTE does not cause an inflammation response from the body.][ NBTE usually occurs during a hypercoagulable state such as system-wide bacterial infection, or pregnancy, though it is also sometimes seen in patients with venous catheters.][ NBTE may also occur in patients with cancers, particularly mucinous adenocarcinoma][ where ]Trousseau syndrome
The Trousseau sign of malignancy or Trousseau's syndrome is a medical sign involving episodes of vessel inflammation due to blood clot (thrombophlebitis) which are recurrent or appearing in different locations over time (thrombophlebitis migrans o ...
can be encountered. Typically NBTE does not cause many problems on its own, but parts of the vegetations may break off and embolize to the heart or brain, or they may serve as a focus where bacteria can lodge, thus causing infective endocarditis.[
Another form of sterile endocarditis is termed ]Libman–Sacks endocarditis
Libman–Sacks endocarditis is a form of non-bacterial endocarditis that is seen in association with systemic lupus erythematosus, antiphospholipid syndrome, and malignancies. It is one of the most common cardiac manifestations of lupus (the most ...
; this form occurs more often in patients with lupus erythematosus and is thought to be due to the deposition of immune complexes.[ Like NBTE, Libman-Sacks endocarditis involves small vegetations, while infective endocarditis is composed of large vegetations.][ These immune complexes precipitate an inflammation reaction, which helps to differentiate it from NBTE. Also unlike NBTE, Libman-Sacks endocarditis does not seem to have a preferred location of deposition and may form on the undersurfaces of the valves or even on the endocardium.][
]
References
Further reading
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External links
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{{Authority control
Inflammations
Rodent-carried diseases
Valvular heart disease