Any of the four heart valves (mitral, aortic, tricuspid, or pulmonary) can be defective or become diseased in a variety of ways. The most common problems occur in the mitral and aortic valves, on the left side of the heart. The most typical causes of valve problems are:
• Congenital defects, meaning that a person is born with an abnor- mal heart valve
• Infectious disease, usually bacterial endocarditis, which can dam- age the valve with scar tissue
• Rheumatic fever, now uncommon
• Changes in valve structure or function that occur with aging
• Coronary artery disease, a heart attack, or heart muscle dysfunc- tion that leads to problems with the way valves work, because of structural changes in the heart or a decrease in blood ?ow to the muscle that controls the valve’s functioning.
The symptoms of valve problems can be subtle and gradual. They differ depending on which valve is involved and what type of malfunction is occurring. (For detailed information about speci?c valve disorders.)

Congenital Valve Defects

Some people are born with a defective valve but may never experience symptoms or may not have problems until later in life. Then the abnor- mal valve may be more vulnerable to calcium deposits that occur as a result of aging or abnormal functioning. If the defect is severe, the symptoms may occur earlier in life.
A valve defect that is congenital (present since birth) also increases a person’s risk of endocarditis, an infection of the lining of the heart (endocardium) or heart valves. Small amounts of bacte- ria may enter your bloodstream but are usually removed by your body’s defense system. However, these bacteria are somewhat more likely to lodge on an abnormal valve, where they can cause an infection that can damage your heart valve. For this reason, if your doctor determines that you have a defective heart valve, to prevent infection you may need antibiotics to kill the bacteria before you have certain dental or surgical procedures.

Infective Endocarditis

Infective endocarditis is an infection of the lining of the heart chambers (endocardium) or the heart valves. It is caused by microorganisms— usually bacteria, but sometimes fungi or other types of microorganisms— that enter your bloodstream and lodge in your heart. These microorgan- isms occur naturally and harmlessly in other parts of your body, such as your mouth or urinary tract, and may enter your bloodstream from any tiny cut or breakdown of tissue (see box, page 194). The presence of bacteria in your bloodstream (which is called bacteremia) does not nec- essarily lead to infection, and not all bacteria are even capable of causing endocarditis. It is a relatively uncommon disease.
When endocarditis does occur, the microorganisms in the bloodstream stick to the surface lining of the heart or abnormal valves, per- haps aided by microscopic blood clots that have formed at the site. Your body responds by sending in immune cells and ?brin (a clotting material) to trap the organism. A clump of cellular material, called a vegetation, forms over the organism. Vegetations can interfere with a valve’s function, or they can break off and block a
blood vessel in a vital organ.
You are more likely to get endocarditis if you have existing valve disease, if you have had heart valve surgery, if you have a congenital heart defect, if you had rheumatic fever as a child that scarred your heart valves, or if you have an arti?cial heart valve or other foreign material in your body. Drug addicts who share needles or use dirty needles are also at risk for endocarditis.
Symptoms of endocarditis are variable, but they usually include fever. Many people report other ?ulike symptoms, too, such as muscle aches and pains, fatigue,
night sweats, and loss of appetite. If you have chronic endocarditis, also known as subacute endocarditis, the symptoms can be subtle and last for months before the diagnosis is made. Sometimes symptoms of heart failure such as shortness of breath and confusion are the ?rst sign of a problem. You or your doctor may also notice changes in your skin and nails, such as red spots on the palms of your hands or the soles of your feet, painful sores on the tips of your ?ngers and toes, or dark lines (tiny hemor- rhages) under your nails that resemble wood splinters. Endocarditis can cause additional problems such as anemia and blood in the urine.
Your doctor may initially suspect endocarditis by your symptoms, especially if you are at known risk because of congenital heart disease, rheumatic fever, or valve disease. He or she will listen to your heart sounds with a stethoscope and may report a new heart murmur (the sound of turbulence in the blood ?ow through your heart) or a change in an old one. From blood samples that are sent for cultures, your doc- tor can identify if there is an infection and which microorganism is caus- ing the infection. Only rarely are blood cultures negative (that is, falsely suggesting no problem) in people with endocarditis. An echocardiogram will often con?rm the diagnosis by showing vegetations on the heart valve. The echocardiogram will also show the size of your heart and indicate how well the valves and heart wall are functioning.
To treat endocarditis, you will need to take intensive doses of antibiotics for 2 to 6 weeks to kill the infecting microorganisms in your bloodstream and to sterilize the heart valve. At ?rst, you will need to be hospitalized so that the antibiotics can be given intravenously. In some people who respond well to the initial treatment, the full course of antibiotics may be completed at home or in a long-term-care facility. Your doctor will want to do regular blood tests to ensure that the med- ication is working.
In some people, endocarditis seriously damages a heart valve (natural or arti?cial). Endocarditis can also cause heart failure, the infection can extend into the heart, or the vegetations can repeatedly break off and travel throughout the bloodstream. Surgery may be necessary to remove infected tissue and repair or replace the valve .

Rheumatic Fever

Rheumatic fever was once the most common cause of heart valve problems. This inflammatory disease, which can develop as a result of untreated strep throat in children more commonly than in adults, occurs in some people when the body’s immune response to ?ght the strep infection mistakenly attacks connective tissue (such as joints or the heart) instead. The affected tissue, often the heart valves, swells and develops scars. On a valve, the scar tissue may interfere with either opening or closing of the valve lea?ets.
Fortunately, the use of penicillin and other antibiotics to treat strep throat has almost eradicated rheumatic fever in the United States. But rheumatic fever remains a concern throughout the world. Without antibiotic treatment, anyone who gets strep throat can develop rheu- matic fever, but it is most likely to occur in children from 5 to 15 years old. There is probably a genetic factor involved that makes some people more susceptible to rheumatic fever. The damage to heart tissue can last a lifetime, although it may not be noticeable for years after the illness.
If you have had rheumatic fever, even decades ago, you are more sus- ceptible to heart attacks and valve disease. Although rheumatic fever rarely affects adults, you are more susceptible to it if you had it in child- hood. Be sure to tell your doctor if you know that you have a history of rheumatic fever; you may need to take preventive antibiotics.

To protect yourself against the rare occurrence of rheumatic fever, it is important to get prompt treatment for a strep throat (caused by Streptococcus bacteria). Symptoms of strep throat include a sore, red throat; dif?culty swallowing; a sudden fever; swelling in the glands in the neck; and sometimes a rash. If you experience these symptoms for 3 days, see your doctor to be tested for a strep infection. With antibiotic treatment, the symptoms are likely to disappear within a few days. It is essential that you continue taking the antibiotics as long as your doctor instructs, even after the symptoms are gone, to reduce the risk of rheu- matic fever (though only a small percentage of strep infections result in rheumatic fever).
Symptoms of rheumatic fever can occur in 3 days to 1 month or more after an untreated strep infection. The symptoms include fever; joint pain or swelling in your wrists, elbows, knees, or ankles; nodules under the skin on your elbows or knees; a raised rash on your chest, back, or stomach; or weakness or fatigue.
See your doctor immediately if you experi- ence these symptoms. He or she will do a throat culture (take a swab of material from your throat for analysis) and may order a chest X-ray or electrocardiogram.
If you have a strep infection that leads to rheumatic fever, your doctor will probably prescribe anti-inflammatory medications, including aspirin, to reduce swelling. You may also need to take a diuretic to get rid of excess fluids. Your doctor may prescribe antibiotic treatment monthly or even daily for life, to prevent reinfection.
If your heart has been damaged by rheumatic fever, you may need to take specific antibiotics if you undergo certain dental or surgical procedures. Surgery to repair or replace a damaged valve may be necessary .