Endocarditis: Heart Infection, Who Is at Risk, Symptoms and Treatment

Endocarditis, also called infective endocarditis, is a rare but life-threatening inflammation of the endocardium — the lining inside the heart's chambers and valves. It usually starts when germs get into the bloodstream and travel to the heart. There they can stick to the lining or get caught in the valves, multiply and cause an infection. Without quick treatment, the infection can damage the heart and lead to serious health problems.

Causes

• Bacteria cause most cases. Many bacteria normally live in the mouth, on the skin and elsewhere in the body, and they can enter the blood through cuts and scrapes, dental work or certain surgeries.
• Fungi, such as yeast, cause some cases. Fungal endocarditis generally affects people whose immune systems are too weak to stop the fungus from growing, including people with HIV.

Who is at higher risk

Endocarditis is rare, and in a healthy person the immune system usually destroys germs in the blood before they cause harm. The risk is higher if you:

• have certain heart conditions. Damaged or abnormal heart tissue, and devices in the heart, trap germs more easily than healthy tissue. That includes heart valve disease, certain congenital heart defects, a pacemaker or implantable defibrillator, and a replacement heart valve.
• are older. Age-related valve changes, such as mitral valve prolapse or calcium deposits on the aortic valve, give germs places to attach.
• inject illegal drugs. Unclean needles can carry bacteria into the blood.
• have a condition that weakens your immune system.
• don't care for your teeth and gums. Poor dental health lets germs into the blood through the gums and mouth.
• have a long-term central venous line — a tube left in a large vein for weeks or months for treatment.
• have had endocarditis before. It can damage heart tissue, which raises the chance of getting it again.

Symptoms

Symptoms can be severe or very mild, can start suddenly or slowly, and differ from person to person. They may include:

• fever and chills;
• a new or worsening heart murmur (an unusual sound between heartbeats);
• chest pain and cough;
• muscle, joint and back pain;
• night sweats;
• shortness of breath;
• skin changes: broken blood vessels, painful red or purple bumps, or painless flat red spots on the palms or the soles of the feet.

Complications

Germs in the heart can clump together with blood cells. Pieces of these clumps can break off and travel through the blood, blocking blood flow, spreading infection or damaging organs such as the brain, lungs, kidneys and spleen. Endocarditis can also lead to sepsis — a medical emergency in which the body responds to an infection in an extreme way — and to heart valve damage, heart failure and arrhythmia, a problem with the rate or rhythm of the heartbeat.

Diagnosis

Your provider will ask about your symptoms, recent illnesses and conditions that raise your risk, examine you, and will likely order tests: blood tests for signs of infection, bacteria or fungi; chest x-rays; and heart tests.

Treatment

Prompt treatment matters. It may include:

• antibiotics for bacterial endocarditis, usually started through an IV in the hospital;
• antifungal medicine for fungal endocarditis — sometimes for life, to keep the infection from returning;
• heart surgery to repair or replace damaged valves and heart tissue, or to remove infected tissue;
• dental care, especially cleanings, to cut down the bacteria growing in the mouth.

Treatment can last weeks, with tests to confirm it is working, and your provider will watch for complications such as heart failure or an irregular heartbeat.

Prevention

If you are at higher risk, you can lower it by:

• caring for your teeth and gums every day;
• having a dental exam and cleaning every 6 months;
• building heart-healthy habits into daily life;
• calling your provider right away if you have possible symptoms.

People at the very highest risk need antibiotics before dental visits and certain medical or surgical procedures. Ask your provider whether you are in that group — and if you are, make sure all your providers know.

Sources

Based on "Endocarditis," MedlinePlus, U.S. National Library of Medicine, drawing on the National Heart, Lung, and Blood Institute (NIH); a work of the United States government in the public domain.