What is Endocarditis and What Causes It?

May 06, 2016

We recently had a friend contract Endocarditis. Before his diagnosis, he had never heard of Endocarditis and we felt it was something that many of our community members would want to learn more about! So we reached out to him to learn more about his experience. After learning more, we thought it would be really beneficial to share what we learned with our community! 

What is Endocarditis?

Endocarditis is an inflammation of the inner layer of the heart also known as the endocardium and it usually involves the heart valves. The inflammation begins if the inner tissue has been damaged, injured, or infected. As a result, those who have artificial heart valves, heart defects or a history of illegal intravenous drugs are at a significantly higher risk of contracting endocarditis. Even a small cut on the tissue may cause a scab to form, damage the endocardium and can lead to the formation of a blood and tissue clot called a thrombus.


There are two types of endocarditis: infective and non-infective. Endocarditis is characterized by lesions, which are known as vegetations. A lesion is any abnormal damage or change in the tissue of an organism, usually caused by disease or trauma. For instance, a cut is a lesion on the skin. The vegetation or lesion may have a white center or granulomatous tissue, which may harden. Once the vegetations stick to the valves, it may spread to other organs and cause infection to those organs affected. The diagnosis of endocarditis is based on clinical features, investigations such as an echocardiogram, and blood cultures demonstrating the microorganism’s activity. (An echocardiogram is a type of ultrasound test that uses high-pitched sound waves that are sent through a device called a transducer. The device picks up echoes of the sound waves as they bounce off the different parts of your heart to see if there are vegetations). Blood cultures are done to test if there are any infections in the blood. Because there are not normally bacteria or fungi in blood, blood cultures will show if there are any abnormal microorganisms in your blood.

If a bacterial infection is causing the endocarditis, your doctor will prescribe one or more antibiotics for 4 to 8 weeks. These antibiotics often have to be given by intravenous (IV) injection. The duration and intensity of treatment depends on the severity of the infection and the type of bacterial organism responsible. Since treatment may last 6 to 8 weeks, it is likely a PICC line will be inserted to receive IV treatment. Heart surgery or surgical valve replacement is sometimes needed for infective endocarditis, especially for people with prosthetic heart valves.

The Difference Between Infective vs. Non-Infective Endocarditis

Infectious agents or pathogens which are usually bacterial cause infective endocarditis, although other organisms can also be responsible. If a bacteria attaches to a valve surface and forms a vegetation, it could be very dangerous and have serious side effects. 

Heart vales do not receive a constant blood supply and the vegetation could block the flow of blood to the valves. A lack of blood flow also hinders the effectiveness of treatments because they have difficulty reaching the infected area due to the clogged valves. Traditional defensive immune system mechanisms such as white blood cells cannot directly reach the valves through the bloodstream either because of the blockage. If the valves have been damaged before, the risk of bacterial attachment increases. Clots can be caused by bacterial or fungal infection, inflaming and damaging the heart cells. The infection then may reach the heart through blood that is carrying a concentration of bacteria, a condition called bacteremia. Once the infectious agent reaches the heart via the blood stream, it tends to concentrate around the valves, through which the blood stream enters and exits the heart. It is important to remember that infective endocarditis is not contagious.

On the other hand, non-infective endocarditis is a form of endocarditis in which small and sterile vegetations tend to aggregate along the edges of the valves or at the cusps. Typically it does not cause many problems on its own, but parts of the vegetations may break off and embolize to the heart or brain. The clot may not be infected but it interferes with heart valve function anyway. The clots form on damaged heart valves that occur from rheumatic fever, autoimmune disorders or even a birth defect. Since non-infective endocarditis is more rare to contract, it is trickier to treat.

Causes of Endocarditis

Endocarditis can involve the heart muscle, heart valves, or lining of the heart. Some people who develop endocarditis have a:

  • Birth defect of the heart
  • Damaged or abnormal heart valves
  • History of endocarditis
  • New heart valve after surgery

Infective Endocarditis begins when germs enter the bloodstream and then travel to the heart.

  • Bacterial infection is the most common cause of endocarditis.
  • Endocarditis can also be caused by fungi, such as Candida.
  • In some cases, no cause can be found.

Germs are most likely to enter the bloodstream by:

  • Central venous access lines
  • Injection drug use, from the use of unclean (unsterile) needles
  • Recent dental surgery
  • Other surgeries or minor procedures to the breathing tract, urinary tract, infected skin, or bones and muscles

Symptoms of Endocarditis

Symptoms of endocarditis may develop slowly or suddenly. Fever, chills, and sweating are frequent symptoms. These sometimes can be present for days before any other symptoms appear. They can also come and go or be more noticeable at nighttime. You may also have fatigue, weakness, and aches and pains in the muscles or joints. Other signs can include:

  • Small areas of bleeding under the nails (also known as splinter hemorrhages)
  • Red, painless skin spots on the palms and soles (Janeway lesions)
  • Red, painful nodes in the pads of the fingers and toes (Osler's nodes)
  • Shortness of breath with activity
  • Swelling of feet, legs, abdomen

If you have these symptoms, please contact your health provider to undergo testing!

Exams and Tests to Help Determine Whether You Have Endocarditis

There are several issues that your health provider may detect. Your health care provider may detect a new heart murmur, or a change in a past heart murmur. An eye exam may show bleeding in the retina and a central area of clearing. This finding is known as Roth's spots. There may be small, pinpoint areas of bleeding on the surface of the eye or the eyelids.

Tests that may be done include:

  • Blood culture to help identify the bacteria or fungus that is causing the infection
  • Complete blood count (CBC), C-reactive protein (CRP), or erythrocyte sedimentation rate (ESR)
  • A routine echocardiogram or a transesophageal echocardiogram to look at the heart valves


You may need to be in hospital to receive IV antibiotics. Blood cultures and tests will help your provider choose the best antibiotic. You will then need long-term antibiotic therapy. People most often need therapy for 4 to 6 weeks to fully kill all the bacteria from the heart chambers and valves. Antibiotic treatments that are started in the hospital will need to be continued at home. Surgery to replace the heart valve is usually needed when:

  • The infection is breaking off in little pieces, resulting in strokes.
  • The person develops heart failure as a result of damaged heart valves.
  • There is evidence of more severe organ damage.

Outlook (Prognosis)

Getting treatment for endocarditis right away improves the chances of a positive outcome. However, ignoring symptoms can result in more serious problems. Problems that may develop include:

  • Brain abscess
  • Further damage to the heart valves, causing heart failure
  • Spread of the infection to other parts of the body
  • Stroke, caused by small clots or pieces of the infection breaking off and traveling to the brain

When to Contact a Medical Professional

Call your health care provider if you notice the following symptoms during or after treatment:

  • Blood in urine
  • Chest pain
  • Fatigue
  • Fever
  • Numbness
  • Weakness
  • Weight loss without change in diet

How Can You Prevent Endocarditis?

The American Heart Association recommends preventive antibiotics for people at risk for infectious endocarditis, such as those with:

  • Certain birth defects of the heart
  • Heart transplant and valve problems
  • Man-made (prosthetic) heart valves
  • Past history of endocarditis

These people should receive antibiotics when they have:

  • Dental procedures that are likely to cause bleeding
  • Procedures involving the breathing tract
  • Procedures involving the urinary tract system
  • Procedures involving the digestive tract
  • Procedures on skin infections and soft tissue infections

Not all cases of endocarditis can be prevented because we do not always know when a bacteremia occurs. However, there are steps that can be taken to lower the risk and likelihood of contracted endocarditis.

For patients whose heart conditions put them at the highest risk for adverse events from infective endocarditis, the American Heart Association recommends antibiotics before certain dental procedures. However for most patients, antibiotics are not needed. Taking proper care of your teeth and gums is the single most important preventative measure you can take. The mouth is a common source of bacteria that can cause infection. Keeping your mouth clean and healthy while maintaining regular dental care will also help reduce the chance of bacteremia from routine daily activities. Early treatment of endocarditis symptoms will help reduce the severity of future treatments.

Care+Wear is committed to helping patients get back to living their lives. We hope this blog post on endocarditis was helpful for those hoping to learn more about it. If you know any patients with endocarditis and receiving treatment through a PICC line, you can check out our fashionable PICC line covers that help secure and protect your PICC line.

We’d love to hear what else you want to learn about as we’re always looking for more great blog post topics.

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