Endocarditis

What is endocarditis?

Endocarditis is an inflammation of the inner lining of the heart (the endocardium) and particularly of the heart valves. Most often it is caused by an infection (infective endocarditis) although there are certain rare non-infective causes too.

Endocarditis is a rare but serious condition that can cause damage to the heart’s chambers and valves. If not treated quickly, endocarditis can be fatal.

What are the symptoms of endocarditis?

Symptoms and presentations of endocarditis can include:

• fever and chills (flu-like symptoms)
• aches and pains in the muscles and joints
• fatigue
• chest pain
• shortness of breath
• swelling in the ankles or feet
• heart murmur
• changes to heart rate e.g. slow or fast heart rate
• stroke
• sepsis
• death

What causes endocarditis?

Endocarditis is most often caused by a bacterial infection, but can also be caused by fungi and other germs.

Bacteria can enter the body through your skin, throat, urinary tract, gums, or digestive system. These bacteria may then enter the bloodstream and travel to the heart.

While people with healthy hearts are unlikely to develop endocarditis, factors that can increase the risk of endocarditis include:

• heart valve disease
• congenital heart disease
• artificial heart valves or implanted cardiac devices such as pacemakers
• heart transplantation
• certain types of cardiomyopathies
• impaired immune system
• injection drug use
• previous history of endocarditis
• rheumatic heart disease
• dialysis

A rare form of this disease is Libman-Sacks endocarditis (LSE), which is characterised by non-infective lesions that commonly affect the aortic and mitral heart valves. Systemic lupus erythematosus (SLE) has been associated with LSE.

How is endocarditis diagnosed?

Diagnosing endocarditis may include several tests, but the most common and reliable test is a heart ultrasound known as an echocardiogram (echo). Types of echos to diagnose endocarditis include:

• Trans-thoracic echo - this will usually be the first test performed, but because the ultrasound beam needs to pass through the chest wall to see the heart this test is not always accurate enough to make the diagnosis
• Trans-oesophageal echo - this is the test of choice. It involves a special echo probe which is passed just like a gastroscopy into the oesophagus and stomach. Because the oesophagus lies directly behind and is in contact with the heart, trans-oesophageal echo provides much better image quality and is superior for diagnosing endocarditis.

Diagnosis may also involve blood cultures – which are special blood tests where the pathology lab will try to grow the bacteria or other organism from the patient’s blood stream. A positive blood culture - where the organism is grown and identified from the patient’s blood - helps to both confirm the diagnosis and also allows doctors to use the specific antibiotics that are most effective for that patient’s infection.

How is endocarditis treated?

Endocarditis is a serious condition that may initially require a stay in hospital. Treatments for endocarditis include:

• a course of antibiotics for bacterial infections
• antifungal medication for fungal infections
• surgery to repair or replace damaged heart valves and/or cardiac devices

How can endocarditis be prevented?

If you are at risk of endocarditis, your cardiologist will advise what precautionary measures should be taken.

This may include a course of antibiotics during high-risk procedures, such as dental procedures where bleeding is likely to occur.