Endocarditis
Valve infection; Staphylococcus aureus - endocarditis; Enterococcus - endocarditis; Streptococcus viridans - endocarditis; Candida - endocarditis
Endocarditis is inflammation of the inside lining of the heart chambers and heart valves (endocardium). It is caused by a bacterial or, rarely, a fungal infection.
Infectious endocarditis involves the heart valves and is most commonly found in people who have underlying heart disease. Sources of the infection may be transient bacteremia, which is common during dental, upper respiratory, urologic, and lower gastrointestinal diagnostic and surgical procedures. The infection can cause growths on the heart valves, the lining of the heart, or the lining of the blood vessels. These growths may be dislodged and send clots to the brain, lungs, kidneys, or spleen.
The interior of the heart is composed of valves, chambers, and associated vessels.
The external structures of the heart include the ventricles, atria, arteries and veins. Arteries carry blood away from the heart while veins carry blood into the heart. The vessels colored blue indicate the transport of blood with relatively low content of oxygen and high content of carbon dioxide. The vessels colored red indicate the transport of blood with relatively high content of oxygen and low content of carbon dioxide.
There are four valves in the heart aortic valve, mitral valve, tricuspid valve, and pulmonary valve. The valves are designed to control the direction of blood flow through the heart. The opening and closing of the heart valves produce the heart-beat sounds.
Janeway lesions are seen in people with acute bacterial endocarditis. They appear as flat, painless, red to bluish-red spots on the palms and soles.
Janeway lesions appear as flat, painless, red or reddish-blue patches on the hands and soles of people with acute bacterial endocarditis.
The valves of the heart open and close to control the flow of blood entering or leaving the heart.
Causes
Endocarditis can involve the heart muscle, heart valves, or lining of the heart. Some people who develop endocarditis have a:
- Birth defect of the heart
- Damaged or abnormal heart valve
- History of endocarditis
- New heart valve after surgery
- Parenteral (intravenous) drug use disorder or addiction
- Long-term intravenous line in place
Endocarditis begins when 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 frequent symptoms. These sometimes can:
- Be present for days before any other symptoms appear
- Come and go, or be more noticeable at nighttime
You may also have fatigue, weakness, weight loss, loss of appetite, and aches and pains in the muscles or joints.
Other signs 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 nodes)
- Shortness of breath with activity
- Swelling of feet, legs, abdomen
Exams and Tests
The health care provider may detect a new heart murmur, or a change in an existing heart murmur.
An eye exam may show bleeding in the retina and a central area of clearing. This finding is known as Roth spots. There may be small, pinpoint areas of bleeding on the surface of the eye or the eyelids called petechiae.
Tests that may be done include:
- Blood culture to help identify the bacteria or fungus that is causing the infection
- Complete blood count (CBC), C-reactive protein (CRP), or erythrocyte sedimentation rate (ESR)
- An echocardiogram to look at the heart valves
Treatment
You may need to be in hospital to get antibiotics through a vein (IV or intravenously). Blood cultures and tests will help your provider choose the best antibiotic.
You will then need long-term antibiotic therapy.
- People most often need therapy for 4 to 6 weeks to kill 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 often needed when:
- The infection is breaking off in little pieces, resulting in strokes or blockages of other arteries.
- The person develops heart failure as a result of damaged heart valves.
- There is evidence of more severe organ damage (such as heart damage).
Outlook (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
When to Contact a Medical Professional
Contact your provider if you notice the following symptoms during or after treatment:
- Blood in urine
- Chest pain
- Fatigue
- Fever that doesn't go away
- 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
- Prosthetic heart valves (heart valves inserted by a surgeon)
- Past history of endocarditis
These people 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
Baddour LM, Anavekar NS, Crestanello JA, Wilson WR. Infectious endocarditis and infections of indwelling devices. In: Libby P, Bonow RO, Mann DL, Tomaselli GF, Bhatt DL, Solomon SD, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 12th ed. Philadelphia, PA: Elsevier; 2022:chap 80.
Baddour LM, Wilson WR, Bayer AS, et al. Infective endocarditis in adults: diagnosis, antimicrobial therapy, and management of complications: a scientific statement for healthcare professionals from the American Heart Association. Circulation. 2015;132(15):1435-1486. PMID: 26373316
Fowler VG, Bayer AS, Baddour LM. Infective endocarditis. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 67.
Holland TL, Bayer AS, Fowler VG. Endocarditis and intravascular infections. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 9th ed. Philadelphia, PA: Elsevier; 2020:chap 80.
Version Info
Last reviewed on: 12/4/2022
Reviewed by: Jatin M. Vyas, MD, PhD, Associate Professor in Medicine, Harvard Medical School; Associate in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
