Endocarditis is most commonly caused by bacteria entering the blood and travelling to the heart.
Although the heart is usually well protected against infection, it may be easier for bacteria to bypass the immune system in people who have:
- a prosthetic (artificial) heart valve – valve replacement surgery is increasingly being used when people experience narrowing of one of their heart valves
- congenital heart disease – where a person is born with heart defects
- cardiomyopathy – where the heart muscle cells have enlarged and the walls of the heart chambers thicken
- damaged heart valves – because of infection or heart disease
People who inject drugs are also more likely to develop endocarditis.
You might also be at higher risk if you have lowered immunity to infection (immunosuppression) due to disease or treatment.
Symptoms of endocarditis
The symptoms of endocarditis can develop rapidly over the course of a few days (acute endocarditis) or slowly, over the course of a few weeks or possibly months (subacute endocarditis).
Subacute endocarditis is more common in people with congenital heart disease.
The most common symptoms of endocarditis include:
- a high temperature (fever) of 38C (100.4F) or above
- night sweats
- shortness of breath, especially during physical activity
- heart murmurs – where your heart makes a whooshing or swishing noise between beats
- tiredness (fatigue)
- muscle and joint pain
Other symptoms can include:
- the appearance of a spotty red rash on the skin (this is known as petechiae)
- narrow, reddish-brown lines of blood that run underneath the nails
- painful raised lumps that develop on the fingers and toes
- painful red spots that develop on the palms of your hand and soles of your feet
- mental confusion
When to seek medical advice
You should contact your GP as soon as possible if you develop any of the above symptoms. This is important particularly if you're at a higher risk of developing endocarditis, such as having a history of heart disease.
These symptoms are more likely to be caused by a less serious type of infection. Your doctor will want to investigate.
When to seek emergency medical advice
A stroke is one of the most serious complications that can develop from endocarditis.
If you suspect a stroke, you should dial 999 immediately to request an ambulance.
The most effective way to identify the symptoms of a stroke is to remember the word FAST which stands for:
- Face – the face may have fallen on one side, the person may be unable to smile, or their mouth or eye may have drooped
- Arms – the person may be unable to raise both arms and keep them there as a result of weakness or numbness
- Speech – the person's speech may be slurred
- Time – it's time to dial 999 immediately if there are any of these signs or symptoms
Endocarditis is treated with a course of antibiotics given via a drip. You'll need to be admitted to hospital for this.
Around one in five people also need surgery to repair or replace a damaged heart valve or drain away any abscesses that develop.
Endocarditis is a serious illness, especially if complications develop.
Even with the highest standard of medical care the risk of dying is around one in five. Early diagnosis and treatment is vital to improve the outlook for the condition.
People who can be affected
Endocarditis is more common in older people, with half of all cases developing in people aged over 50.
Cases of endocarditis have been recorded in children, particularly those born with congenital heart disease. Twice as many men are affected as women.
Rates of endocarditis are increasing because of advances in medical care.
This is due to an increasing number of people being treated with valve replacement surgery or surgery to repair congenital heart disease.