Infective Endocarditis

Infective endocarditis is an infection that can seriously damage heart valves and cause other serious complications if it is not treated quickly with antibiotics. Surgery to replace, or repair, damaged valves is also often needed. If you are at increased risk of this infection, do report promptly to your doctor any symptoms that you think may be due to infective endocarditis. The earlier the condition is diagnosed and treated, the better the likely outcome.

What is infective endocarditis

Infective endocarditis is an infection that affects some part of the endocardium. The endocardium is the tissue that lines the inside of the heart chambers. The infection usually involves one or more heart valves which are part of the endocardium. It is a serious infection that is life-threatening.

What are the symptoms and signs of infective endocarditis

Slowly developing infection:

In many cases the infection develops quite slowly. This is sometimes called subacute bacterial endocarditis (SBE). Symptoms can develop gradually, over weeks or months, and can be vague at first. You tend to feel generally unwell and may have general aches and pains, tiredness, and be off your food. A fever (a high temperature) develops at some stage in most cases. As these first symptoms can be caused by a lot of other conditions, the cause of the symptoms may not be diagnosed for some time. Heart murmurs tend to develop. These are sounds that can be heard by a doctor listening to your heart with a stethoscope. Murmurs are caused by abnormal flow of blood through faulty or damaged valves. If you already have a heart murmur from an existing valve problem, the murmur may change or become more intense. A new or changing murmur is often what alerts a doctor to suspect infective endocarditis.

Rapidly developing infection

In some cases the symptoms develop quite quickly and you can become very unwell over a few days. The speed at which the illness develops partly depends on which bacterium or fungus is causing the infection. Some bacteria are more virulent (aggressive) than others.

What are the possible complications

Complications usually develop if the infection is left untreated, or if treatment is delayed.

Complication in the heart

The infection can damage heart valves. This can lead to serious problems such as heart failure. (See separate leaflet called Heart Failure.) In some cases, the infection spreads and can damage other parts of the heart. For example, the infection may spread to affect the conducting (electrical) system of the heart and cause the heartbeat to become erratic. In some cases, an abscess (ball of pus) forms in the heart muscle nearby.

Complications in other parts of the body

Small bits may break off from the vegetations on the infected heart valves. These are called infected emboli and get carried in the bloodstream, and lodge in other parts of the body. This can cause various symptoms - for example:

  • Small spots may appear under fingernails, in the eyes, or on other parts of the body.
  • Infections may develop in other parts of the body.
  • The spleen may enlarge, as it is the main organ that fights off blood infections.
  • If a larger chunk of vegetation breaks off then it can block the blood flow in a main artery. For example, if it gets stuck in an artery in the brain it can cause a stroke or sudden loss of vision in one eye.