Condition: Endocarditis

Endocarditis is an inflammation of the lining of the heart

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What is endocarditis?

In Greek, “itis” means inflammation.  The endocardium is the inner lining of the heart- The myocardium is the muscle, and the epicardium is on the outside of the heart. The Pericardium is on the outside of the heart, not part of the heart itself.

Endocarditis is an inflammation of the lining of the heart and most commonly affects the heart valves, causing them to malfunction.

What causes endocarditis?

Endocarditis is rarely caused by drugs or the body reacting to itself (auto-immune disease), but most commonly, it can be due to bacterial or fungal infection. The heart valve can sometimes be normal before the infection, but more commonly, the valve is abnormal and the increased turbulence around the abnormality makes it more prone to getting infection.

Usually problems in the heart that create a large pressure gradient- i.e. between a low pressure chamber and high pressure chamber lead to an increased chance of endocarditis.

There are a number of valve problems that patients have prior to endocarditis including:

  • Aortic valve stenosis – high pressure gradient between the left ventricle and the outflow blood vessel- the aorta. This can be treated using Transcatheter Aortic Valve Intervention (TAVI)
  • Aortic regurgitation – the leak on the valve means blood flows back through the valve when the aortic pressure is high, and the left ventricle pressure is low
  • Mitral stenosis – increased gradient from the left atrium to the left ventricle
  • Mitral regurgitation – a leak on the mitral valve meaning that when the heart contracts, the high pressure jet goes backwards into the left atrium.
  • Ventricular septal defect – High pressure between the left ventricle and the right ventricle

Right sided heart problems – much less common and more likely if you have indwelling catheters in the heart (e.g. dialysis) or have used intravenous drugs with dirty needles.

What problems
can endocarditis cause?

With a bacterial or fungal infection deep in your body several things can happen:

  • The valve deteriorates and leaks badly which puts a strain on the heart.
  • The infection causes “lumps of inflammation and infection” also known as “vegetations” in which can break off and cause stroke, heart attack or gut and kidney problems depending on where they land.
  • An abscess can form in your heart. This means surgery will be needed as antibiotics cannot get into the abscess.
  • Septicaemia – the infection can cause you to be very sick, with fever, sweat, and rigors.
  • Renal failure – the kidneys can fail as a reaction to inflammation in the body.

How is
endocarditis diagnosed?

It can sometimes be difficult to diagnose endocarditis however when you are generally unwell and have a known valve problem, the suspicion is high and  tests can be carried out to rule it out. Common tests include:

  • ECG – if an abscess develops the ECG can change with infection, and ECG will show a fast heart rate.
  • Echocardiogram – an Echo from the outside of the body may identify the vegetation, but even a transoesophageal echocardiogram cannot rule out endocarditis and if the resolution is 2mm or so it could miss a small infection.
  • Bloods – a blood count, renal function, liver function, and markers of inflammation such as C-Reactive Protein are routinely done. Blood cultures should be taken at least 6 times to be sure any bug is not a contaminant from the skin, but is growing in the bloods.
  • Chest X ray – to see if there is lung infection or heart failure.
  • CT or MRI head – if you are confused, or have a weak arm or leg, we need to exclude any infection in the brain.

Urine dipsticks – to see if the kidneys are damaged and leaking blood or protein.

Preventing and treating endocarditis


To reduce your risk of endocarditis consider these:

  • Avoid self medicating with the injection of drugs, especially dirty needles.
  • Good dental hygiene – many of the bugs that cause endocarditis come from the mouth, especially if you are immunosuppressed or have a known valve problem. It is advised to get regular dental check-ups.
  • Consider antibiotics prophylaxis for dental procedures if you have an existing valve problem, have had endocarditis or have a mechanical or tissue artificial valve. You can learn more about artificial heart valves.
  • See your GP if you feel very unwell to exclude endocarditis.


  • Antibiotics –  As with any infection, early use of antibiotics is vital.  These are usually given for 6 weeks to ensure the infection is gone.
  • Surgery –  If the antibiotics do not bring the fever down, an abscess is present, or the vegetation are large, surgery may be needed as an emergency. If the valve is damaged but stable, then surgery may be needed at a later stage.

At OneWelbeck Heart Health, we can provide rapid assessment with all the above tests within 24 hours to put your mind at ease.

Endocarditis Specialists

Our Heart Health specialists at OneWelbeck in London are leaders in their field. They are equipped with the latest diagnostic medical technology at custom-built, day-case facilities to investigate any symptoms and ensure you receive the best available care.