Endocarditis is an infection of the inner lining of the heart and its valves. The infection is caused by bacteria or fungi that enter the bloodstream through the mucous membranes of the mouth, open wounds, needles. It can also occur from medical procedures which involve cutting through infected skin.
Normally, bacteria which enter the bloodstream pass harmlessly through the heart and are killed by the immune system. However, bacteria circulating through the bloodstream may attach to heart tissue that is already damaged by heart disease or to an artificial heart valve. When this happens, the bacteria can hide from the immune system and cause a dangerous infection.
Endocarditis can lead to other life-threatening conditions. Stroke or reduced blood flow to other organs can occur when clumps of bacteria break off from the heart and block the blood vessels. The bacteria which cause endocarditis can also spread to other organs, causing additional tissue damage. Uncontrolled endocarditis can permanently damage the heart valves, eventually leading to heart failure.
Endocarditis is caused by bacteria or fungi that enter the bloodstream from outside the body. Endocarditis is unusual in people with healthy hearts. Some heart diseases or disorders, and some procedures used to treat certain types of heart disease, make people more susceptible to endocarditis, including:
- Congenital heart disease
- Valve disease
- Hypertrophic cardiomyopathy
- Implantation of an artificial heart valve
- Implanted devices, such as a pacemaker
Patients who had endocarditis once are more susceptible to another heart infection. People who use intravenous drugs, and those who have a compromised immune system (for example, from HIV or from an organ transplant) are also more likely to develop a heart infection.
The most common symptoms of endocarditis mimic the flu or other viral infections, including:
- Sweating, night sweats
- Lack of energy, weakness
- Aching joints and muscles
Other symptoms can include:
- Small areas of bleeding under the nails (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)
- Tiny purple or red spots on the skin, whites of the eyes, or in the mouth
- Trouble breathing
- Persistent cough
- Weight loss for no known reason
- Swelling of the feet, legs, or abdomen
Symptoms of endocarditis can develop quickly (within days) or slowly (over the course of weeks).
Tests commonly used to diagnose endocarditis include:
- Blood tests: Blood cultures are performed to determine what type of bacteria or fungi are causing the infection. Different types of infections require different treatments. A complete blood count is also done to look for damage to the blood cells. When endocarditis is suspected, blood cultures should be done before antibiotics are given. These drugs can mask the presence of infective organisms in the bloodstream.
- Echocardiogram: to look at the heart valves and blood vessels
- Electrocardiogram (ECG): to identify problems with heart rhythm that can be caused by an infection
- Chest X-rays, computed tomography (CT), or magnetic resonance imaging (MRI) : to look for physical damage to the heart or other organs.
Very high doses of antibiotics or antifungal drugs are used to treat the heart infection. They are delivered directly into a vein though an intravenous (IV). The drugs are usually given continuously for about six weeks. Drug treatment for endocarditis begins in the hospital, but some patients can complete their IV treatment at home.
Sometimes surgery is needed to remove damaged tissue or areas of infection. Fungal infections are harder than bacterial infections to treat with drugs alone.
Surgery may also be needed to repair or replace a heart valve damaged by endocarditis.
Patients at high risk for endocarditis should practice good dental hygiene, including regular brushing, flossing and visits to the dentist. The bacteria that cause endocarditis often enter the bloodstream though tissue damage in the mouth caused by poor dental hygiene (gingivitis).
Patients at high risk for endocarditis should also avoid cosmetic procedures, such as piercing or tattooing, which can push bacteria from the skin into the bloodstream. Patients at high risk should also see a doctor if they have normal wounds that do not heal quickly.
Finally, patients at high risk for endocarditis may be prescribed preventive antibiotics before some medical procedures, including dental work that involves cutting into the gums or teeth, or certain types of surgery.