HEART & BLOOD Cardiovascular System • Aortic aneurysm • High blood pressure (hypertension) • High blood cholesterol • Thrombophlebitis • Rheumatic fever • Varicose veins • Heart arrhythmias • Atrial fibrillation • Endocarditis • Aortic valve stenosis • Aortic valve regurgitation • Mitral valve stenosis • Mitral valve regurgitation • Pulmonary hypertension • Raynaud's disease • Long QT syndrome • Mitral valve prolapse • Pericarditis • Cardiomyopathy • Myocarditis • Arteriosclerosis / Atherosclerosis • Peripheral arterial disease (PAD) • Low blood pressure (hypotension) • Aortic dissection • Lymphedema • Pulmonary valve stenosis • Ventricular septal defect (VSD) • Tetralogy of Fallot • Coarctation of the aorta • Atrial septal defect (ASD) • Patent ductus arteriosus (PDA) • Left ventricular hypertrophy • Bundle branch block • Heart murmurs • Patent foramen ovale • Transposition of the great arteries • Hypoplastic left heart syndrome • Sudden cardiac arrest • Prehypertension • Tricuspid atresia • Ebstein's anomaly • Buerger's disease

Note: All links within content go to MayoClinic.com

The inside of your heart contains four chambers and four valves lined by a thin membrane called the endocardium. Endocarditis is an infection of this inner lining.

Endocarditis typically occurs when bacteria or other germs from another part of your body, such as your mouth, spread through your bloodstream and lodge in your heart. Left untreated, endocarditis can damage or destroy your heart valves. The consequences can be life-threatening.

Endocarditis is rare in people with healthy hearts. People at greatest risk of endocarditis have a damaged heart valve, an artificial heart valve or other heart defects.

If you're at risk of endocarditis, you may need antibiotics before certain medical or dental procedures. Also watch for signs and symptoms of infection. Prompt treatment can help you avoid this serious condition.

Endocarditis may develop slowly or suddenly — depending on what's causing the infection and whether you have any underlying heart abnormalities.

Signs and symptoms may include:

• Fever
• Chills
• Weakness
• Fatigue
• Aching joints and muscles
• Night sweats
• Shortness of breath
• Paleness
• Persistent cough
• Swelling in your feet, legs or abdomen
• Unexplained weight loss
• Blood in your urine
• A new heart murmur
• Tenderness in your spleen — an infection-fighting abdominal organ on your left side, just below your rib cage

Sometimes endocarditis causes red, tender spots under the skin of the fingers. These are known as Osler's nodes. You may notice tiny purple or red spots known as petechiae (puh-TE-ke-e) on other areas of the skin. Similar spots may appear in the whites of your eyes or under your fingernails.

Endocarditis occurs when germs enter your bloodstream, travel to your heart and lodge on abnormal heart valves or damaged heart tissue. Bacteria are the cause of most cases, but fungi, viruses or other microorganisms also may be responsible.

Sometimes the culprit is one of many common bacteria that live in your mouth, upper respiratory tract or other parts of your body. In other cases, the offending organism may gain entry to your bloodstream through:

• Certain dental or medical procedures. Any dental procedure that causes bleeding may allow bacteria to enter your bloodstream. Bacteria may be a concern with procedures involving the respiratory, urinary or intestinal tract as well.
• An infection or other medical condition. Bacteria may spread from an infected area, such as a skin sore. Gum disease, a sexually transmitted disease or an intestinal disorder — such as inflammatory bowel disease — also may give bacteria the opportunity to enter your bloodstream.
• Catheters or needles. Bacteria can enter your body through a catheter — a thin tube that doctors sometimes use to inject or remove fluid from the body. Contaminated needles and syringes are a concern for people who use intravenous (IV) drugs.
• Common activities. Even everyday activities such as brushing your teeth or chewing food can allow bacteria to enter your bloodstream — especially if your teeth and gums are in poor condition.

Typically, your immune system destroys bacteria that make it into your bloodstream. Even if bacteria reach your heart, they may pass through without causing an infection.

Most people who develop endocarditis have a diseased or damaged heart valve — an ideal spot for bacteria to settle. This damaged tissue in the endocardium provides bacteria with the roughened surface they need to attach and multiply.

If your heart is healthy, you're unlikely to develop endocarditis. Even most types of heart disease don't increase the risk of endocarditis. The organisms that cause infection tend to adhere to and multiply only in malformed, damaged or surgically implanted heart valves.

You're at risk of endocarditis if you have:

• Damaged heart valves. Certain medical conditions — such as the once-common childhood illness rheumatic fever — can damage or scar one or more of your heart valves, making them more prone to infection.
• Congenital heart defects or heart valve defects. If you were born with an abnormal heart valve or other heart defect, your heart may be more susceptible to infection.
• Other heart valve problems. Severe mitral valve prolapse is the most common heart condition associated with endocarditis. In this condition, your mitral valve — one of the four heart valves that normally open and close to allow blood to flow in only one direction through your heart — doesn't close properly. In severe cases, the valve may even allow blood to flow backward in your heart.
• Artificial heart valve. An artificial heart valve can provide a spot for bacteria to settle and multiply, infecting the surrounding tissue. Bacteria can also be introduced into your heart during surgery to implant an artificial valve.
• Thickening of the heart muscle. This rare condition, known as hypertrophic cardiomyopathy, impedes blood flow through the heart. It can damage or distort heart valves. Signs and symptoms include shortness of breath, chest pain and loss of consciousness with exertion.
• A history of endocarditis. An episode of endocarditis nearly always injures your heart, increasing the risk of a future heart infection.

If you have a known heart defect or heart valve problem, ask your doctor about your risk of developing endocarditis. Even if your heart condition has been repaired or hasn't caused symptoms, you may still be at risk.

Some people without heart problems are at risk of endocarditis as well. Intravenous drug users have a greater risk of infection because sharing or reusing needles can expose the bloodstream to infectious agents. People who are hospitalized with IV tubes also may be exposed to infection.

If you develop signs or symptoms of endocarditis, see your doctor right away — especially if you have risk factors for this serious infection. Although less serious conditions can cause similar signs and symptoms, you won't know for sure until you see a doctor.

Your doctor may suspect endocarditis based on your medical history and physical signs and symptoms, such as fever. Using a stethoscope to listen to your heart, your doctor may hear a new heart murmur or a change in a previous heart murmur — possible indicators of endocarditis.

The infection can mimic other illnesses in its early stages. Various tests may be necessary to help make the diagnosis:

• Blood tests. Blood tests can help your doctor identify certain conditions, including anemia — a shortage of healthy red blood cells that can be a sign of endocarditis. Blood tests can also help your doctor identify the type of bacteria or other microorganism that may be infecting your heart.
• Echocardiogram. This test uses sound waves to produce images of your heart at work. Your doctor may detect abnormal thickening or leakage of heart valves, or even abnormal growths (vegetations) that contain collections of bacteria — a telltale sign of endocarditis.
• Transesophageal echocardiogram. This type of echocardiogram allows your doctor to get a closer look at your heart valves. It's often used to check for vegetations or infected tissue. During this test, an ultrasound device is passed through your mouth and into your esophagus — the tube that connects your mouth and stomach.
• Electrocardiogram (ECG). In this test, patches with wires (electrodes) are attached to your skin to measure your heart's electrical impulses. The impulses are displayed as "waves" on a monitor or printed on paper. An infection in the heart can cause disruptions in the normal flow of electrical rhythms through your heart.
• Chest X-ray. An X-ray image of your chest allows your doctor to check your heart and lungs for physical abnormalities. Because endocarditis can make it harder for your heart to pump blood normally, an X-ray may reveal blood and fluid backed up into your lungs.

Endocarditis can cause clumps of bacteria and cellular debris (vegetations) to form in your heart at the site of the infection. These clumps can break loose and travel to your brain, lungs, abdominal organs or kidneys. This may cause various problems, including stroke, neurological changes and organ damage.

Left untreated, endocarditis can damage your heart valves and permanently destroy your heart's inner lining. This can cause your heart to work harder to pump blood. Eventually, you may experience heart failure — a chronic condition in which your heart is unable to pump enough blood to meet your body's needs. If the infection progresses, it's usually fatal.

If your doctor suspects that you have endocarditis, you may need high doses of intravenous antibiotics in the hospital. Blood tests may help identify the type of microorganism that's infecting your heart. This information will help your doctor choose the best antibiotic or combination of antibiotics to fight the infection.

You may need to take antibiotics for up to six weeks to clear up the infection. Once your fever and the worst of your signs and symptoms have passed, you may be able to leave the hospital and continue antibiotic therapy in an outpatient setting. You'll need to see your doctor regularly to make sure your treatment is working.

Report to your doctor any signs or symptoms that your infection is getting worse, such as:

• Fever
• Headaches
• Joint pain
• Blood in your urine
• Chills

Diarrhea, a rash, itching or joint pain may indicate a reaction to an antibiotic — another reason to call your doctor.

Finally, see your doctor immediately if you experience shortness of breath or swelling in your legs, ankles or feet. These signs and symptoms may indicate heart failure.

If the infection damages your heart valves, you may have symptoms and complications for years after treatment. Sometimes surgery is needed to treat persistent infections or replace a damaged valve.

Certain dental and medical procedures may allow bacteria to enter your bloodstream. Antibiotics can help destroy or control these harmful bacteria.

If you're at risk of endocarditis, you may need to take antibiotics before:

• Procedures that may cause bleeding in your mouth. Your doctor or dentist may prescribe an antibiotic to be taken by mouth one hour before any procedure that may cause bleeding in your mouth — including routine dental cleanings. In some cases, an injectable antibiotic may be prescribed.
• Procedures involving the respiratory, urinary or intestinal tract. You may need antibiotics before having your tonsils or adenoids removed or having certain types of throat exams. Antibiotics may be recommended before procedures affecting the bladder, prostate or urethra. Some gynecological procedures (not including routine pelvic exams or Pap tests) call for antibiotics as well. If your risk of endocarditis is high, your doctor may recommend taking injectable antibiotics just before the procedure and again six hours afterward. If your risk is lower, you may only need oral antibiotics before the procedure.
• Certain nonmedical procedures. It also may be wise to take antibiotics before procedures such as ear piercing and body tattooing. Check with your doctor ahead of time to find out the best way to protect yourself.

If you're at risk of endocarditis, let all of your health care providers know. You may want to request an endocarditis wallet card from the American Heart Association. Check with your local chapter or print the card from the association's Web site.

To help prevent endocarditis, take good care of yourself. Pay special attention to your dental health. Brush and floss your teeth and gums often, and schedule regular dental checkups.