Dr. Rae Osborn 07 Jun 2022

Endocarditis by definition is when there is an inflammation of the endocardium layer of the heart, which includes the valves. There are two forms of endocarditis: infective and non-infective. Infective involves pathogenic organisms like bacteria while non-infective relates to physiological processes that compromise the valves leading to future problems.

Non-infective endocarditis is rarer than infective and occurs because clots and blood platelets stick to the valves resulting in inflammation and infection.

Causes of endocarditis

The causes of non-infective endocarditis include the following:

  • Vasculitis: An inflammatory response of the blood vessels.
  • Immune complexes: An immune system complex is when an antigen and antibody are bound together. This is a normal response of the immune system but research shows that this can be related to endocarditis; this is also the case in some patients who have Covid-19.
  • Hypercoagulation: In this situation, blood clotting happens too readily resulting in a buildup of clots on valve tissue.
  • Systemic lupus erythematosus: Commonly called lupus, this is an autoimmune disease.
  • Behçet disease: This is an uncommon blood vessel disease that can impact the valves.
  • Hypereosinophilic syndrome: A condition where there are too many eosinophils, which cause organ damage and result in Löffler endocarditis.
  • Marantic endocarditis: The condition that is also called nonbacterial thrombotic endocarditis (NBTE), where there are deposits on the valves; this often involves the mitral (bicuspid) valve.

The causes of infective endocarditis are the following:

  • Fungi: The fungus Candida albicans, is commonly found causing thrush and although not commonly a cause of endocarditis, it can happen in patients who are immunocompromised.
  • Viruses: There have been some cases of infective endocarditis in patients with Covid-19; it occurs as an uncommon complication of the viral infection.
  • Bacteria: Streptococcus and Staphylococcus can infect the heart valves. These are the most common pathogens implicated in causing bacterial endocarditis.

Bacteria can spread from the gums and teeth during dental procedures. Subacute bacterial endocarditis or SBE takes longer to develop (weeks) while acute bacterial endocarditis happens in days. SBE is most common when people already have a valve defect.

Endocarditis symptoms

The signs of endocarditis are not always obvious and can also indicate a different condition, making diagnosis problematic. There are some similar and different symptoms depending on if the endocarditis is due to infection or not.

Non-infective endocarditis symptoms:

  • Fever
  • Shortness of breath
  • Heart murmur: A situation where a sound is heard through a stethoscope indicating abnormal heart valve function.
  • Heart palpitations: A person has the feeling that the heart is fluttering or that the heartbeat is too rapid.
  • Valvular regurgitation: This is when the valves don’t close properly so that some blood leaks backward during heart muscle contractions.

Infective endocarditis symptoms:

Symptoms of endocarditis that are subacute bacterial or acute bacterial include the following:

Endocarditis complications

Endocarditis is a dangerous illness to have because it directly affects the heart and also indirectly impacts other organs in the body.

Non-infective endocarditis can also lead to complications such as embolization. This is when blood clots that are formed travel through the blood vessels and become deposited in vessels or other organs of the body. Some of the following consequences of emboli can result:

Infective endocarditis also has dangerous potential complications that can lead to organ failure and death.

Complications of infective endocarditis:

  • Valve regurgitation and heart failure
  • Inflammation of the aorta
  • Atrial fibrillation
  • Abscess of the myocardium: The myocardium is the muscle layer of the heart.
  • Infected material that spreads throughout the body.
  • Blood clots in the lungs
  • Glomerulonephritis: A type of kidney infection.
  • Infection in the central nervous system.

Risk factors for endocarditis

Certain people are at a higher risk for endocarditis, these are given below.

  • Intravenous drug users who use dirty needles inadvertently introduce bacteria into their bloodstream.
  • Immunocompromised people, such as individuals who have cancer, cannot easily fight off infections making them vulnerable to infective endocarditis.
  • People who already have cardiovascular system problems such as heart valve disorders such as calcification of the valves or congenital heart defects such as mitral valve prolapse.
  • Individuals who have an artificial heart valve.

Endocarditis diagnosis

The diagnosis of endocarditis is important because the complications are serious and can be deadly. The diagnostic measures can also help determine if the illness is the non-infective or infective type, which can determine what treatment measures are most appropriate.

The tests include:

  • Blood test: This includes a complete blood cell count and clotting time determination. There may be an increase in white blood cells and immunoglobulin complexes but these are not specific to endocarditis.
  • Blood cultures: Cultures can show if there are bacteria or other pathogens that are present in the blood that can be due to infective endocarditis.
  • Echocardiography: This is a type of ultrasound in which the heart is visualized to show if there are any valvular or other heart structural abnormalities present.
  • Clinical exam: If patients show symptoms along with results from the tests indicated above (specifically the blood culture and echo), then it is likely endocarditis is present.

Endocarditis treatment

Survival rates for non-infective endocarditis are lower than for infective endocarditis because the patients already have other serious illnesses compromising their ability to recover. Treatment for non-infective endocarditis is by the use of anticoagulant medicine to help stop blood clots from forming.

For infective endocarditis:

Potential sources of infection such as catheters need to be checked and removed. Dental health needs to also be evaluated to determine if this could be the source of bacteria. Prophylactic antibiotics are needed for dental work for those patients who have heart valve defects. This reduces the chance of future infective endocarditis.

Intravenous antibiotics are given for infective endocarditis. The antibiotics used are:

  • Gentamycin
  • Penicillin
  • Ampicillin


Endocarditis is a dangerous illness to have with mortality rates of about 25%. It is, therefore, paramount that the correct diagnosis is made in a timely manner. It is also essential that a doctor determines first what type of endocarditis a patient has and then, takes steps to treat the condition before any dangerous complications take place.

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About the Author:

Dr. Rae Osborn has a Ph.D. in Biology from the University of Texas at Arlington. She was a tenured Associate Professor of Biology at Northwestern State University where she taught many courses for Pre-nursing and Pre-medical students. She has written extensively on medical conditions and healthy lifestyle topics, including nutrition. She is from South Africa but lived and taught in the United States for 18 years.