Conditions Inflammation of the inner lining of the heart (endocarditis)

Endocarditis is the inflammation of the endocardium. The endocardium is the thin membrane that lines the inside of the heart. It is sometimes referred to as the lining of the heart. The endocardium also forms the valves of the heart. Endocarditis therefore usually also affects the heart valves.

Most cases of endocarditis are caused by a pathogen, such as bacteria or fungi. In rare cases, endocarditis has other causes, such as serious illnesses like cancer or autoimmune disorders.

Severe progression and complications can often be avoided with early diagnosis and treatment. 

Acute endocarditis caused by a pathogen is often accompanied by a high temperature and chills. However, the inflammation can also develop gradually, causing a slight fever over an extended period.

Other possible symptoms include:

• weakness
• headache
• joint and muscle pain
• loss of appetite, weight loss, nausea and vomiting

The person may also experience symptoms that indicate a problem with the heart. These include:

• chest pain
• shortness of breath
• abnormal sounds when a doctor listens to the heart (murmurs)
• an accelerated heartbeat
• fluid retention

Endocarditis can also cause a stroke and neurological symptoms may occur, including:

• impaired sensitivity
• visual impairment
• hemiplegia (paralysis on one side of the body) 
• difficulty speaking
• severe headache

If the inflammation progresses, symptoms include the following distinctive skin changes:

• Osler nodes: painful, bluish-red nodules about the size of a lentil, which occur on the fingers and/or toes
• Janeway lesions: painless, very small red lesions on the hands and feet
• Petechiae (blood spots): red dots the size of a pinhead, which usually occur in one part of the body

Endocarditis is almost always caused by bacteria – mainly staphylococcal, streptococcal and enterococcal bacteria. The most common type of bacteria to cause endocarditis is Staphylococcus aureus.

In very rare cases, fungi such as candida and aspergillus can cause inflammation of the endocardium. 

Also in very rare cases, endocarditis may occur when blood platelets (thrombocytes), proteins or immune cells may be deposited on the endocardium and the heart valves. This can occur as a result of other serious illnesses, such as cancer or autoimmune disorders. A blood clotting disorder can also make these kinds of deposits more likely to develop, especially if the person has a pre-existing heart valve disorder.

Several factors and pre-existing conditions can increase the risk of developing endocarditis. Risk factors for endocarditis caused by a pathogen include:

• congenital or acquired heart conditions, such as hypertrophic cardiomyopathy
• an artificial heart valve, pacemaker or other artificial material in the heart
• long-term dialysis therapy
• diabetes mellitus
• a weakened immune system, for example, due to medication or HIV/AIDS
• injecting drugs into the veins using unsterile equipment
• poor oral and dental hygiene

People with a blood clotting disorder are particularly vulnerable to endocarditis that is not caused directly by a pathogen. This can also occur as part of other health conditions, such as:

• cancer and autoimmune disorders
• hereditary clotting disorders
• blood poisoning (sepsis)
• severe burns

Endocarditis is rare. Every year in developed countries, it is estimated that between 3 and 10 people in every 100,000 develop endocarditis due to infection with a pathogen. Men are twice as likely as women to be affected. 

With acute endocarditis, the patient’s condition deteriorates rapidly. The milder form that begins more gradually (subacute endocarditis) often goes unnoticed for a long time. 

If endocarditis is not detected and treated in good time, serious complications and long-term effects can occur – including death of the patient. Almost 25 percent of adults who require hospital treatment for infective endocarditis will die either during treatment or later due to long-term effects.

The mortality rate for endocarditis is lower in children. Between 5 percent and 10 percent of children who are treated in hospital for infective endocarditis will die. 

Possible complications and long-term effects include:

• heart failure
• severe malfunction of the heart valves
• blood poisoning (sepsis) with multi-organ failure
• severe cardiac arrhythmias (irregular heartbeat), such as AV block
• blockages of the blood vessels, for example, a stroke or 
  pulmonary embolism

Endocarditis is not always easily diagnosed as it has a wide range of symptoms, some of which can also occur with other conditions.

During a consultation, a doctor will determine potential risk factors for endocarditis when taking a detailed medical history. These include, for example, an artificial heart valve or a congenital heart disease.

Other possible indicators are recent surgeries or dental treatments, during which pathogens may have entered the body.

Further indications of endocarditis may be discovered during a physical examination. These include unusual heart sounds when the doctor listens to the heart, or changes visible on the skin and nails.

If endocarditis is suspected, an echocardiogram and blood tests will usually be performed.

An echocardiogram or “echo” is an ultrasound scan of the heart. It allows doctors to check the structure and movement of the organ. 

Blood tests are performed to check for the presence of pathogens. Blood cultures, in which bacteria and fungi in the blood can grow, are created in a lab. 

Further indications of an inflammation can also be found by measuring inflammatory markers and the level of white corpuscles (also known as white blood cells or leukocytes) in the blood.

Certain antibodies and clotting factors in the blood may also help narrow down the cause of endocarditis.

If doctors are still unable to make a definitive diagnosis following these tests, additional imaging techniques may be used, such as X-ray, computed tomography (CT), or magnetic resonance imaging (MRI).

Antibiotics are used to treat endocarditis caused by bacteria. 

Antimycotics (anti-fungals), i.e., drugs that specifically target fungi, are used if the cause is a fungal infection. Antibiotics or antimycotics are usually administered over several weeks via an infusion into the bloodstream.

In many cases, treatment with medication alone is not sufficient to treat endocarditis – for example, if the heart valves are already seriously damaged by the inflammation and are no longer fully functional.

Surgery is then often required to prevent heart failure and other complications. The operation involves the surgeon removing the inflamed tissue. In most cases, the affected heart valve is replaced with an artificial heart valve. 

In people with endocarditis caused by another illness, the pre-existing condition is treated first. The treatment may also aim to prevent the formation of blood clots. In most cases, the patient will need to take anticoagulants (anti-clotting medication) such as heparin on a long-term basis. Under certain circumstances, such as acute heart failure, surgery may also be required. 

Following treatment, doctors will check the patient’s heart using an ultrasound scan (echocardiogram). This scan determines the condition and functioning of the heart.

Blood tests are performed again to check certain blood values and levels of white corpuscles in the blood. This indicates whether the inflammation has reduced. Regular check-ups are an important element of aftercare for endocarditis. 

People who have survived endocarditis or who are at an increased risk of developing endocarditis, e.g., following surgical procedures on the heart valves, are advised to observe good skin and dental hygiene. They should also attend preventive dental check-ups on a regular basis. In advance of certain surgical procedures and dental treatments, it is recommended – in consultation with a doctor – to take an antibiotic on a preventive basis to avoid developing endocarditis again. If anyone at an increased risk of developing endocarditis notice any sign of infection (e.g., high temperature or lethargy), they should always consult a doctor.