Endocarditis is an inflammation of the endocardium (the thin layer of tissue cells lining the inner surface of the heart muscle and valves). This inflammation can be infectious or noninfectious. Noninfectious causes include systemic lupus erythematosus or rheumatic fever. The inflammation can also be infectious, meaning that organisms (such as bacteria, yeast or fungi) attach themselves to the endocardium, usually on the heart valves, leading to growth and destruction of the lining and damage to the valves.
The amount of valve damage depends on the type of inflammation (infectious or noninfectious) and the exact cause of the inflammation. With a bacterial cause, or bacterial endocarditis, the damage can be severe, although it typically depends on the type of bacteria as some are worse than others.
Noninfectious endocarditis can occur in anyone with an underlying inflammatory disease. Infectious endocarditis usually occurs in people who get infected with certain types of infectious agents which cause damage to the heart valves or who already have some damage or abnormalities of their endocardium. The latter can occur in people who have had rheumatic fever, artificial valves or breakdown of normal valve tissue by aging or a prior episode of endocarditis.
Also, individuals born with certain types of heart defects are predisposed to getting endocarditis from bacteria that would not affect a person born without these defects. The reason for endocarditis in all of these individuals is that there is either a preexisting valve or tissue abnormality (leading to places where bacteria can attach themselves) or very aggressive bacteria can attach itself even to a normal valve. Once the bacteria attach themselves or gain a foothold, they begin to multiply. This, in turn, causes inflammation and damages the heart valve.
People with endocarditis have a variety of symptoms. The symptoms may appear over a period of days or weeks. In early stages of infectious endocarditis, the symptoms may be mistaken for the flu.
The most usual symptoms are persistent fevers, rash, night sweats, chills, loss of appetite, fatigue, weight loss, and joint and muscle pain. These symptoms are nonspecific and may be seen in many types of inflammation. Symptoms of heart failure such as fatigue, shortness of breath, elevated heart rate or rate of breathing, swelling of the legs, lightheadedness or fainting are more specific for a heart problem. Neurological problems, including strokes, may occur in people with endocarditis. This is due to debris from the inflammation flipping off the valves and going through the blood stream to the brain.
Occasionally, there is inflammation of the electrical system of the heart (conduction system) which may cause rhythm abnormalities or heart block.
The diagnosis is made by a physician first obtaining a history and then performing a physical examination. The history may describe persistent and prolonged fevers. The examination may show an abnormal heart exam with abnormal murmurs. Other parts of the physical examination may show evidence of infectious debris in the toes or fingers which suggest that there is an infection of the heart valves.
The combination of the symptoms listed here and an abnormal heart examination may alert a physician to the possibility of endocarditis. If your doctor suspects endocarditis, other tests may be ordered. Special tests such as an electrocardiogram, chest x-ray and echocardiogram may help to make the diagnosis of an abnormal valve or vegetations. Vegetations are accumulations of inflammatory and/or infectious debris that are attached to the heart valves or inside lining of the heart. Blood tests (e.g., a blood count or blood cultures) may be helpful to show the presence of infection or inflammation. The vegetations on the valves give off a shower of bacteria into the bloodstream which can be cultured and identified so that appropriate antibiotics may be given.
Damage to the heart valve from any cause means the valves will not open and close normally. Usually, the problem with endocarditis is that the valves do not close properly or have holes in them which cause leaks. These leaks mean that every time the heart pumps blood out, some of the blood leaks back into the heart through the leaky valve. In very serious cases, most of the blood that gets pumped out leaks right back to the heart so that the blood does not get to the places it is supposed to. This means the heart is failing (heart failure) because it cannot pump adequately and supply the needs of the body. In less severe cases, smaller amounts of leakiness occur and only cause the heart chambers to be enlarged.
If the cause is a bacterial infection, it needs to be treated with antibiotics. Due to the seriousness of the infection, patients with endocarditis are usually hospitalized. The antibiotics are usually given intravenously at the start of treatment, and may sometimes be given by mouth later on. The duration and method of treatment (oral or i.v.) depends on the exact type of bacteria, the status of the heart, the ability of the patient to take medication and other factors. The cure of the infection is very important to try to minimize damage to the valve. If the cause is a fungus, an antifungal drug will be used. If the cause is non-infectious, the underlying inflammation is treated (such as aspirin for rheumatic fever). If there is significant leakiness of the valves, medicines may be given to make the heart pump better and reduce the blood pressure, so the heart doesn't have to work as hard. If the valve leakiness is very severe, surgery may be needed to fix or replace the valve. If the infection is in an artificial valve, it may have to be replaced to treat the infection. If severe heart rhythm abnormalities occur, and cause heart block, a pacemaker may be needed.
For non-infectious endocarditis, treating the primary disease can help prevent the heart from becoming inflamed. In patients predisposed to getting endocarditis (at higher risk due to congenital or acquired heart defects), the risk can be reduced by decreasing the risk of having bacteria in the bloodstream. This can be done by having good dental hygiene (bad teeth and gums cause more bacteria to get into the blood), and taking antibiotics prior to procedures (such as certain types of surgery, a genitourinary or gastrointestinal exam, or dental cleaning) in cardiac patients who are at risk for endocarditis which are known to increase the chances of bacteria getting into the blood. The antibiotics kill the bacteria before they have a chance to infect the heart.
It all depends on the cause and type of inflammation and the severity of leakiness. Successful treatment of the infection may not be enough to restore normal health. This varies from individual to individual. The damage to the heart valves may interfere with or completely prevent their normal function. Abnormal valve function causes the heart to work harder and may cause heart enlargement. Exercise tolerance may be limited. Severe valve damage may result in congestive heart failure that requires valve replacement surgery. Your doctor can describe the severity of the valve problem and whether medications or special restrictions are needed.