Endocarditis is inflammation of the inside lining of the heart chambers and heart valves (endocardium).A.D.A.M.

Causes, incidence, and risk factors

Endocarditis can involve the heart muscle, heart valves, or lining of the heart. Most people who develop endocarditis have a:

• Birth defect of the heart
• Damaged or abnormal heart valve
• History of endocarditis
• New heart valve after surgery

Endocarditis begins when different germs enter the bloodstream and then travel to the heart.

• Bacterial infection is the most common cause of endocarditis.
• Endocarditis can also be caused by fungi, such as Candida.
• In some cases, no cause can be found.

Germs are most likely to enter the bloodstream during:

• Central venous access lines
• Injection drug use, from the use of unclean (unsterile) needles
• Recent dental surgery
• Other surgeries or minor procedures to the breathing tract, urinary tract, infected skin, or bones and muscles

Symptoms

Symptoms of endocarditis may develop slowly or suddenly.

Fever, chills, and sweating are the classic symptoms. These sometimes can:

• Be present for days before any other symptoms appear
• Come and go, or be more noticeable at nighttime

Fatigue, weakness, and aches and pains in the muscles or joints may also be present.

Other symptoms can include:

• Small areas of bleeding under the nails (splinter hemorrhages)    
• Red, painless skin spots on the palms and soles (Janeway lesions)
• Red, painful nodes in the pads of the fingers and toes (Osler's nodes)
• Shortness of breath with activity
• Swelling of feet, legs, abdomen

Signs and tests

The health care provider may detect a new heart murmur, or a change in a past heart murmur.

An eye exam may show bleeding in the retina and a central area of clearing. This is known as Roth's spots. There may be small, pinpoint areas of bleeding on the surface of the eye or the eyelids. 

Tests that may be done include:

• Blood culture -- helps identify the bacteria or fungus that is causing the infection
• Complete blood count (CBC), C-reactive protein (CRP), or erythrocyte sedimentation rate (ESR)
• A routine echocardiogram or a transesophageal echocardiogram provides a closer look at the heart valves

Treatment

You may need to be hospitalized at first to receive antibiotics through a vein (IV or intravenously). Blood cultures and tests will help your health care provider choose the best antibiotic.

You will then need long-term antibiotic therapy.

• Patients usually need therapy for 4-6 weeks to fully remove all the bacteria from the heart chambers and valves.
• Antibiotic treatments that are started in the hospital will need to be continued at home.

Surgery to replace the heart valve is usually needed when:

• The infection is breaking off in little pieces, resulting in strokes
• The person develops heart failure as a result of damaged heart valves
• There is evidence of more severe organ damage

Expectations (prognosis)

Getting treatment for endocarditis right away improves the chances of a good outcome.

More serious problems that may develop include:

• Brain abscess
• Further damage to the heart valves, causing heart failure
• Spread of the infection to other parts of the body
• Stroke, caused by small clots or pieces of the infection breaking off and traveling to the brain

Calling your health care provider

Call your health care provider if you notice the following symptoms during or after treatment:

• Blood in urine
• Chest pain
• Fatigue
• Fever
• Numbness
• Weakness
• Weight loss without change in diet

Prevention

The American Heart Association recommends preventive antibiotics for people at risk for infectious endocarditis, such as those with:

• Certain birth defects of the heart
• Heart transplant and valve problems
• Man-made (prosthetic) heart valves
• Past history of endocarditis

These patients should receive antibiotics when they have:

• Dental procedures that are likely to cause bleeding
• Procedures involving the breathing tract
• Procedures involving the urinary tract system
• Procedures involving the digestive tract
• Procedures on skin infections and soft tissue infections

References

1. Fowler VG Jr, Scheld WM, Bayer AS. Endocarditis and Intravascular Infections. In: Mandell GL, Bennett JE, Dolin R, eds. Principles and Practice of Infectious Diseases. 7th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2009; chapt 77.
2. Karchmer AW. Infective Endocarditis. In: Bonow RO, Mann DL, Zipes DP, Libby P, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 9th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 67.
3. Wilson W, Taubert KA, Gewitz M, et al. Prevention of infective endocarditis: guidelines from the American Heart Association: a guideline from the American Heart Association Rheumatic Fever, Endocarditis, and Kawasaki Disease Committee, Council on Cardiovascular Disease in the Young, and the Council on Clinical Cardiology, Council on Cardiovascular Surgery and Anesthesia, and the Quality of Care and Outcomes Research Interdisciplinary Working Group. Circulation. 2007 Oct 9;116(15):1736-54. [PubMed: 17446442]

Review Date: 7/16/2012.

Reviewed by: Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.