What Is Endocarditis?

Endocarditis is a severe disease that can significantly affect the functioning of the heart. Unfortunately, it has deadly consequences if it isn't treated in time.
What Is Endocarditis?

Last update: 16 January, 2023

Cardiovascular disease is responsible for a large number of deaths worldwide. The disease can affect any part of the heart. However, there’s a disease called endocarditis that can affect the inner lining of the organ. Keep reading to find out more about it!

What is endocarditis?

It’s a heart disease caused by inflammation of a part of the heart called the endocardium. The endocardium is nothing more than the inner lining of the heart’s chambers and valves. The pathology is usually very serious and endangers people’s lives.

Inflammation of the endocardium can occur for multiple reasons, although the most common cause is a bacterial infection. Therefore, the disease is also known as infective endocarditis.

The pathology can affect people of any age and gender. However, studies affirm that it’s more common in men, who represent up to 80% of cases. In addition, its frequency is higher in people between 27 and 37 years of age.

Types of endocarditis

Fever in endocarditis
Many cases of endocarditis are very extended, due to the diagnostic difficulties of the disease.

This disease can be classified according to its evolution. Endocarditis can be acute, subacute, and in prosthetic valves, each of which has a different severity.

  • Subacute endocarditis: This is a form of slow progressive development, and months may pass before symptoms appear. This infection is aggressive, but it offers the doctor some time to act and initiate treatment.
  • Acute endocarditis: This is an aggressive and rapidly evolving endocarditis, so symptoms appear within a few days. In this case, it’s possible to identify where the microorganisms enter, and it can affect normal and abnormal valves.
  • Endocarditis of valve prostheses: This is one that appears in the first year after a valve replacement. The infections closest to the procedure are associated with bacteria with resistance to antibiotics, so they are more severe.


Infective endocarditis is characterized by the formation of vegetations on the heart valves or in the tissue adjacent to them. Vegetations are produced by an accumulation of blood clots and bacteria, which affect valve function.

The main systemic symptoms appear due to the dysfunction of the affected valve and the infection itself. In this sense, people may experience some of the following clinical manifestations:

  • Fever
  • Muscle and joint pain
  • Night sweats
  • Fatigue
  • Weight loss
  • Increase in cardiac frequency
  • Difficulty breathing
  • Petechiae (small reddish skin lesions that are due to microbleeds)
  • The appearance of a heart murmur of variable intensity
  • Anemia

Some studies establish that up to 90% of patients have only fever, fatigue, and weight loss. For its part, endocarditis also has certain characteristic signs such as Janeway lesions, which are petechiae located on the hands and feet. Osler’s nodules (similar, but slightly larger) can also be seen in this disease.

Possible complications

Endocarditis is a very dangerous disease that must be treated as soon as possible to avoid the appearance of complications in other organs. Most complications are the result of the detachment of a piece of vegetation, which can obstruct the lumen of a blood vessel.

Taking this into account, the main complications of endocarditis include the following:

  • Irreversible damage to the heart valves
  • Cerebrovascular disease (CVD)
  • Abscesses in the heart and other organs
  • Pulmonary embolism
  • Pneumonia and empyema
  • Kidney damage

Causes of endocarditis

As previously mentioned, in most cases the disease is due to a bacterial infection of the endocardium. The germs most frequently implicated in the infection are streptococci and Staphylococcus aureus. A group of microorganisms called HACEK bacteria are also frequent causative agents.

The bacteria that cause endocarditis come from a distant infection such as a skin abscess or tonsillitis. They invade the bloodstream, reach the heart, and produce the characteristic infection.

The penetration of bacteria into the blood occurs most frequently through the skin, mucosa, or respiratory tract. It’s important to note that endocarditis can also be caused by multiple fungi or viruses entering the bloodstream, although its frequency is much lower.

On the other hand, there are non-infectious causes of endocarditis. These are due to the formation of sterile thrombi composed of platelets and fibrin that adhere to the valves, as well as to the endocardium.

Risk factors

Endocarditis can affect people of any age, however, there are multiple situations that predispose people to suffer from the disease. One of the biggest risk factors is valve problems, especially those caused by rheumatic fever.

Other factors that increase the likelihood of infective endocarditis include the following:

  • Advanced age
  • The use of catheters for a prolonged period of time
  • Injecting drugs
  • Congenital heart conditions
  • Performing invasive dental or medical procedures without proper hygiene measures
  • Implanted cardiovascular devices
  • History of endocarditis
  • Artificial heart valves

Diagnosis of endocarditis

Endocarditis is difficult to diagnose.
After a detailed physical examination, the cardiologist may perform an echocardiogram to confirm abnormalities typical of endocarditis.

Endocarditis is suspected by medical personnel when a fever is present for a long time without an obvious sign of infection. The suspicion is more evident if there’s an associated heart murmur and a history of cardiovascular conditions.

The diagnosis of endocarditis is confirmed with a blood culture and an echocardiogram. The blood culture consists of taking blood and exposing it to a special medium in order to isolate the pathogenic germ.

For its part, the echocardiogram allows the specialist to confirm the presence of vegetations in the heart valves. It also allows them to observe the functioning of the heart and determine the severity of the situation.


The main treatment for infective endocarditis is the use of high-dose intravenous antibiotics. The type of antibiotic will depend on the bacteria causing the infection. In addition, the treatment is long, and can last between 2 and 8 weeks.

On the other hand, fungal infections should be treated with a specific antifungal, depending on the causative agent. Treatment, in this case, is also carried out intravenously, at high doses, and for several weeks.

Medical personnel should treat any adjacent infection or complication. In this regard, skin abscesses should be drained, necrotic tissue debrided, and any infected devices removed.

Some people may need surgery to replace the damaged valve or to treat persistent infections. Also, some endocarditis caused by fungi require surgery to achieve remission of the disease.

An illness that needs immediate attention

Endocarditis is an infectious disease characterized by the presence of vegetations on the heart valves. Symptoms of the disease are usually very general, making it difficult to diagnose in most cases.

Unfortunately, it’s a severe and very aggressive condition that warrants immediate medical attention. In this sense, it’s essential to consult a specialist if you suffer from a fever of unknown origin for a long time. Only medical personnel are trained to treat the condition and prevent complications.

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