Bacterial endocarditis
Bacterial endocarditis, also known as infective endocarditis, is a serious infection of the endocardium, the thin membrane lining the heart. This condition typically arises when bacteria enter the bloodstream and attach to damaged heart tissues, particularly the heart valves. It is most prevalent in individuals with pre-existing heart conditions, which can exacerbate the risk of infection. Symptoms can range from mild to severe and may include fever, chills, fatigue, unexplained weight loss, and skin manifestations like red dots or bumps on fingers and toes. Diagnosis often involves a thorough medical history, physical examination, and various tests, such as blood cultures and echocardiograms.
Treatment typically requires hospitalization for intravenous antibiotics, lasting four to six weeks, and may necessitate surgery if the infection leads to significant heart damage or if antibiotics are ineffective. Preventive measures are crucial, especially for individuals with certain heart conditions, and may include taking antibiotics before invasive procedures and maintaining good oral hygiene. Awareness and prompt medical attention for potential symptoms are vital for better outcomes in those at risk.
Bacterial endocarditis
- ANATOMY OR SYSTEM AFFECTED: Blood, cardiovascular system, heart, tissue
- ALSO KNOWN AS: Infective endocarditis
Definition
The endocardium is a thin membrane that covers the inner surface of the heart. Bacterial endocarditis is an infection of this membrane. Infection occurs when bacteria attach to the membrane and grow.
The infection is most common when the heart or heart valves have already been damaged. It can be life-threatening, and it can permanently impair the heart valves. This can lead to serious health problems, such as congestive heart failure.
The infection can also cause growths on the valves or other areas of the heart. Pieces of these growths can break off and travel to other parts of the body. This can cause serious complications.
Causes
Bacteria can travel to the heart through the blood. They can enter the blood from an infection elsewhere in the body. They can also enter through breaks in the skin or mucous membranes caused by dental work, surgery, or IV (intravenous) drug use. Only certain bacteria cause this infection, the most common of which are streptococci, staphylococci, and enterococci.
The bacteria may then be able to attach to the endocardium. Some heart conditions can increase the chance of infections. These conditions may cause blood flow to be obstructed or to pool, providing a place for the bacteria to build up.
Risk Factors
According to the National Organization for Rare Disorders, there are between two and twelve cases of bacterial endocarditis per 100,000 people each year in developing countries. The following conditions place a person at greater risk for bacterial endocarditis during certain procedures: heart valve scarring from rheumatic fever or other conditions; artificial heart valve; congenital heart defect; cardiomyopathy; prior episode of endocarditis; and mitral valve prolapse, with significant regurgitation (abnormal backflow of blood).
The foregoing conditions increase the risk of the infection with certain activities, including IV drug use (risk is extremely high when needles are shared); any dental procedure, even cleanings; removal of tonsils or adenoids, and other procedures involving the ears, nose, and throat; bronchoscopy (viewing the airways through a thin, lighted tube); and surgery on the gastrointestinal or urinary tracts, including the gallbladder and prostate.
Symptoms
Symptoms of bacterial endocarditis vary from mild to severe, depending on the bacteria causing the infection, the number of bacteria in the bloodstream, the extent of structural heart defects, the body’s ability to fight infection, and overall health. The symptoms, which can begin within two weeks of the bacteria entering the bloodstream, include fever, chills, fatigue, weakness, malaise, unexplained weight loss, poor appetite, muscle aches, joint pain, coughing, shortness of breath, bumps on the fingers and toes, and little red dots on the skin, inside the mouth, or under the nails. The first symptom may be caused by a piece of the infected heart growth breaking off.
Screening and Diagnosis
A doctor will ask about symptoms and medical history and perform a physical exam, including listening to the patient’s heart for a murmur. Tests may include blood cultures to check for the presence of bacteria; blood tests to look for signs of infections and complications related to endocarditis; a computed tomography (CT) scan (a detailed X-ray picture that identifies abnormalities of fine tissue structure); an electrocardiogram (ECG or EKG), which is a test that records the heart’s activity by measuring electrical currents through the heart muscle; an echocardiogram, which is a test that uses high-frequency sound waves (ultrasound) to examine the size, shape, and motion of the heart; and a transesophageal echocardiogram, in which ultrasound is passed through the patient’s mouth and then into the esophagus to better visualize the heart valves.
Treatment and Therapy
Treatment, including medications and possible surgery, focuses on getting rid of the infection from the blood and heart. Antibiotics are given through an IV into a vein. The patient must be admitted to the hospital for this treatment, which could take four to six weeks to complete. If the antibiotics fail to remove the bacteria, or if the infection returns, surgery may be needed. Surgery may also be necessary if the infection has damaged the heart or valves.
Prevention and Outcomes
The best way to prevent endocarditis is to avoid the use of illegal IV drugs. Certain heart conditions may increase the risk, too. To find out if the patient is at increased risk for this condition, the doctor should be consulted.
The American Heart Association (AHA) recommends that people with high and moderate risk should take antibiotics before and after certain dental and non-dental medical procedures. In addition, the AHA recommends taking an antibiotic just before and after any procedure that may put a person at risk.
The patient should tell their dentist and other health professionals about the heart condition. Other preventive measures include maintaining good oral hygiene, brushing teeth twice daily, flossing daily, visiting a dentist for a cleaning at least every six months, and seeing a dentist if dentures cause discomfort. Finally, people should seek medical care immediately for symptoms of an infection.
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